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2023,42(4):1-6
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.001
Abstract:
Landscape architecture should fully play its positive role in the context of global climate change and the target of carbon peak and neutrality proposed by China government. The practical actions of landscape architecture in various countries taken to address the goals of carbon peak and neutrality were learned about through exclusively interviewing International Federation of Landscape Architects Asia Pacific Region Climate Change Working Group. The goals and prospects for the development of landscape architecture in the future were proposed from two aspects including the flexible design and low-carbon design of landscape architecture.
Landscape architecture should fully play its positive role in the context of global climate change and the target of carbon peak and neutrality proposed by China government. The practical actions of landscape architecture in various countries taken to address the goals of carbon peak and neutrality were learned about through exclusively interviewing International Federation of Landscape Architects Asia Pacific Region Climate Change Working Group. The goals and prospects for the development of landscape architecture in the future were proposed from two aspects including the flexible design and low-carbon design of landscape architecture.
2023,42(4):7-15
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.002
Abstract:
An intervention approach framework for landscape architecture to promote public participation in the response to climate change was proposed based on the three process dimensions of “cognition-emotion-behavior” of public participation and the theory of planned behavior to enhance the key role of landscape architecture in promoting public participation in the response to climate change.Three levels including willingness to enhance， action to stimulate， and long-term investment were covered.Seven key measures for intervention were included.In terms of enhancing awareness， the climate change information should be integrated into a multi-sensory public space design and activity system， and the spatial elements should be used to simulate possible local climate change impacts， in order to create climate change cognition and establish emotional links.In terms of stimulating action， pop-up experiences should be created and participatory low-carbon should be established.In terms of long-term guarantee mechanism， policy guarantees for public participation in the response to climate change should be promoted.The self-organization platforms in community should be built.The funding sources should be expanded.The feedback mechanisms for response actions should be improved.The sustainable public participation should be encouraged.Finally， three specific suggestions that China needs to focus on promoting public participation in the response to climate in the future were put forward based on the national conditions in China.Mainly including： changing traditional slogan promotion methods in the stage of increasing willingness， and integrating more climate change information into planning and design.Prioritize low-cost participatory low-carbon activities during the action phase to promote public participation.In the long-term investment stage， under the guidance of the government， expand funds and build self-organizing platforms， and develop sustainable evaluation feedback.
An intervention approach framework for landscape architecture to promote public participation in the response to climate change was proposed based on the three process dimensions of “cognition-emotion-behavior” of public participation and the theory of planned behavior to enhance the key role of landscape architecture in promoting public participation in the response to climate change.Three levels including willingness to enhance， action to stimulate， and long-term investment were covered.Seven key measures for intervention were included.In terms of enhancing awareness， the climate change information should be integrated into a multi-sensory public space design and activity system， and the spatial elements should be used to simulate possible local climate change impacts， in order to create climate change cognition and establish emotional links.In terms of stimulating action， pop-up experiences should be created and participatory low-carbon should be established.In terms of long-term guarantee mechanism， policy guarantees for public participation in the response to climate change should be promoted.The self-organization platforms in community should be built.The funding sources should be expanded.The feedback mechanisms for response actions should be improved.The sustainable public participation should be encouraged.Finally， three specific suggestions that China needs to focus on promoting public participation in the response to climate in the future were put forward based on the national conditions in China.Mainly including： changing traditional slogan promotion methods in the stage of increasing willingness， and integrating more climate change information into planning and design.Prioritize low-cost participatory low-carbon activities during the action phase to promote public participation.In the long-term investment stage， under the guidance of the government， expand funds and build self-organizing platforms， and develop sustainable evaluation feedback.
2023,42(4):16-22
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.003
Abstract:
A healthy living environment is an important cornerstone of all development in human society，but global climate change has plunged it into crisis.The emergence of concept of Anthropocene has laid a scientific foundation for the correct understanding of the relationship between man and nature.As a discipline connecting people，sites and environment，landscape architecture can play a key role in encouraging and leading living environment related disciplines to jointly cope with the global climate crisis.In order to meet the challenge of landscape architecture in the Anthropocene era，this article reviews the characteristics of landscape architecture in the Anthropocene.It points out that climate change，as the primary symbol of the Anthropocene，has a wide range of impacts on landscape architecture.The main objectives of landscape architecture to address climate change are summarized in depth by establishing a logical link between climate change，the human world and landscape architecture.Some feasible solutions and strategies are put forward.It will provide useful reference for the update and development of landscape architecture theories and practices.
A healthy living environment is an important cornerstone of all development in human society，but global climate change has plunged it into crisis.The emergence of concept of Anthropocene has laid a scientific foundation for the correct understanding of the relationship between man and nature.As a discipline connecting people，sites and environment，landscape architecture can play a key role in encouraging and leading living environment related disciplines to jointly cope with the global climate crisis.In order to meet the challenge of landscape architecture in the Anthropocene era，this article reviews the characteristics of landscape architecture in the Anthropocene.It points out that climate change，as the primary symbol of the Anthropocene，has a wide range of impacts on landscape architecture.The main objectives of landscape architecture to address climate change are summarized in depth by establishing a logical link between climate change，the human world and landscape architecture.Some feasible solutions and strategies are put forward.It will provide useful reference for the update and development of landscape architecture theories and practices.
2023,42(4):23-31
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.004
Abstract:
The increasing natural disasters caused by climate change and the national carbon peak and carbon neutrality target have brought historical opportunities for the development of landscape architecture，but the voice of landscape architecture in China’s response to climate change is still insufficient.In order to enhance the significance of landscape architecture in coping with climate change，clarify its responsibilities and responsibilities in this field，and explore the innovative approaches of landscape architecture in climate design，this study，based on a comprehensive analysis of relevant domestic and foreign literature and policy measures on coping with climate change，examines the fields that landscape architecture can contribute to from two aspects of climate change mitigation and adaptation.The results show that landscape architecture needs to meet national needs such as climate change adaptation，disaster management，and carbon peak and carbon neutrality，etc.，and strengthen multi-disciplinary integration.On the one hand，carbon sequestration and sink increase in urban and rural living environment and carbon emission reduction should be achieved through climate positive design.On the other hand，it also needs to adapt to climate change through landscape planning and design，reduce disaster risk，and enhance urban and rural resilience.The innovative approaches of landscape architecture in climate design include standardization direction，spatial quantitative transformation，ecological integrity orientation，multi-scale observation and implementation，and educational reform and innovation.The above results show that landscape architecture has great potential in coping with climate change.The innovative exploration of climate design can promote the paradigm transformation and innovative development of landscape architecture disciplines and provide Chinese solutions to climate change.
The increasing natural disasters caused by climate change and the national carbon peak and carbon neutrality target have brought historical opportunities for the development of landscape architecture，but the voice of landscape architecture in China’s response to climate change is still insufficient.In order to enhance the significance of landscape architecture in coping with climate change，clarify its responsibilities and responsibilities in this field，and explore the innovative approaches of landscape architecture in climate design，this study，based on a comprehensive analysis of relevant domestic and foreign literature and policy measures on coping with climate change，examines the fields that landscape architecture can contribute to from two aspects of climate change mitigation and adaptation.The results show that landscape architecture needs to meet national needs such as climate change adaptation，disaster management，and carbon peak and carbon neutrality，etc.，and strengthen multi-disciplinary integration.On the one hand，carbon sequestration and sink increase in urban and rural living environment and carbon emission reduction should be achieved through climate positive design.On the other hand，it also needs to adapt to climate change through landscape planning and design，reduce disaster risk，and enhance urban and rural resilience.The innovative approaches of landscape architecture in climate design include standardization direction，spatial quantitative transformation，ecological integrity orientation，multi-scale observation and implementation，and educational reform and innovation.The above results show that landscape architecture has great potential in coping with climate change.The innovative exploration of climate design can promote the paradigm transformation and innovative development of landscape architecture disciplines and provide Chinese solutions to climate change.
2023,42(4):32-41
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.005
Abstract:
The adverse effects of global climate change on the production and life of human including extreme drought, sea level rise, and reduced biodiversity are increasingly receiving attention.Landscape architecture can mitigate and adapt to the negative impacts of climate change by coordinating the relationship between humans and nature.Constructing a method and system for landscape architecture in responding to climate change has important and practical significance for better utilizing the functions of landscape architecture and promoting the development of landscape architecture disciplines.Three shortcomings in existing practices including insufficient understanding of the complexity of climate change, a disconnect between theory and practice in addressing climate change, and a lack of guarantee mechanisms for implementation were summarized by reviewing the practices and related concepts of landscape architecture in response to climate change at home and abroad.This article tentatively proposed the design of climate initiative for landscape architecture to positively address the comprehensive driving factors of climate change.The design method and technical system of climate initiative should be constructed from the perspectives of definition, characteristics, processes, methods, and implementation mechanisms.It will provide reference for the practice of designing landscape architecture with climate initiative.
The adverse effects of global climate change on the production and life of human including extreme drought, sea level rise, and reduced biodiversity are increasingly receiving attention.Landscape architecture can mitigate and adapt to the negative impacts of climate change by coordinating the relationship between humans and nature.Constructing a method and system for landscape architecture in responding to climate change has important and practical significance for better utilizing the functions of landscape architecture and promoting the development of landscape architecture disciplines.Three shortcomings in existing practices including insufficient understanding of the complexity of climate change, a disconnect between theory and practice in addressing climate change, and a lack of guarantee mechanisms for implementation were summarized by reviewing the practices and related concepts of landscape architecture in response to climate change at home and abroad.This article tentatively proposed the design of climate initiative for landscape architecture to positively address the comprehensive driving factors of climate change.The design method and technical system of climate initiative should be constructed from the perspectives of definition, characteristics, processes, methods, and implementation mechanisms.It will provide reference for the practice of designing landscape architecture with climate initiative.
2023,42(4):42-52
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.006
Abstract:
Flood disasters are the main risk faced by coastal cities due to climate change. Based on the IPCC's definition of risk， this article constructed an assessment model of flood risk index based on hazard， vulnerability， and exposure. 11 evaluation indicators were used to calculate the flood risk index with scenario simulation and GIS spatial overlay methods. The Huangpu River waterfront space in Shanghai was selected as the study area for empirical analysis. Scenarios in 2030， 2050， and 2100 were simulated. The spatial pattern of flood risk under climate change goals in the Huangpu River waterfront area was obtained based on the results of evaluation. Furthermore， a single-factor overlay evaluation was conducted based on population density to identify the “Three Zones and Three Policies” for landscape renewal in the Huangpu River waterfront space through scenario simulation. The results of assessing the flood-prone area showed that the risk level is increasing year by year according to the spatial pattern of flood risk under the objective of climate change in the Huangpu River waterfront. Both upstream and downstream parts of Huangpu River show high flood risk sections in the scenario simulation in 2050 and 2100. The coastline that adopts resistance （flood control） strategies has been increasing year by year， posing an increasing threat to areas with high urban population density. The number of shorelines adopting evacuation strategies has been increasing year by year， and the livability of water banks has decreased. The number of shorelines adopting coexistence （flood carrying） strategies is decreasing year by year， and more resistance and evacuation strategies are needed. According to the flood risk zoning policy of Huangpu River waterfront from the perspective of climate change， the flood area is located to the east of Baoshan District and the Northwest Angle of Pudong New Area. The Huangpu River waterfront space needs to adopt a retreat and evacuation strategy， implement population evacuation， plan the “estuary protection plan”， and construct ecological wetlands in the middle reaches of the Songjiang District. The flood-resistant area is located in the central urban area， and the waterfront space needs to continue to adopt flood-resistant strategies， with increasing risks. The assessment of the flood bearing area is located in most of the Huangpu waterfront spaces， and the strategy of coexisting with the flood can be adopted， but the potential is increasingly shrinking.
Flood disasters are the main risk faced by coastal cities due to climate change. Based on the IPCC's definition of risk， this article constructed an assessment model of flood risk index based on hazard， vulnerability， and exposure. 11 evaluation indicators were used to calculate the flood risk index with scenario simulation and GIS spatial overlay methods. The Huangpu River waterfront space in Shanghai was selected as the study area for empirical analysis. Scenarios in 2030， 2050， and 2100 were simulated. The spatial pattern of flood risk under climate change goals in the Huangpu River waterfront area was obtained based on the results of evaluation. Furthermore， a single-factor overlay evaluation was conducted based on population density to identify the “Three Zones and Three Policies” for landscape renewal in the Huangpu River waterfront space through scenario simulation. The results of assessing the flood-prone area showed that the risk level is increasing year by year according to the spatial pattern of flood risk under the objective of climate change in the Huangpu River waterfront. Both upstream and downstream parts of Huangpu River show high flood risk sections in the scenario simulation in 2050 and 2100. The coastline that adopts resistance （flood control） strategies has been increasing year by year， posing an increasing threat to areas with high urban population density. The number of shorelines adopting evacuation strategies has been increasing year by year， and the livability of water banks has decreased. The number of shorelines adopting coexistence （flood carrying） strategies is decreasing year by year， and more resistance and evacuation strategies are needed. According to the flood risk zoning policy of Huangpu River waterfront from the perspective of climate change， the flood area is located to the east of Baoshan District and the Northwest Angle of Pudong New Area. The Huangpu River waterfront space needs to adopt a retreat and evacuation strategy， implement population evacuation， plan the “estuary protection plan”， and construct ecological wetlands in the middle reaches of the Songjiang District. The flood-resistant area is located in the central urban area， and the waterfront space needs to continue to adopt flood-resistant strategies， with increasing risks. The assessment of the flood bearing area is located in most of the Huangpu waterfront spaces， and the strategy of coexisting with the flood can be adopted， but the potential is increasingly shrinking.
2023,42(4):53-63
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.007
Abstract:
In the context of global climate change and sea level rise， coastal disasters will have a significant impact on the landscape and socio-economic development of coastal cities. Guangzhou， a coastal city in the Pearl River Delta， was used to construct a “sensitivity adaptabilit” vulnerability assessment framework based on the land use and socio-economic data in the area. The vulnerability characteristics of urban landscape system in Guangzhou under three different scenarios of sea level rise superimposed with storm surge risk in the short-term （2030）， the medium-term （2050） and the long-term （2100） were assessed. The results showed that the agricultural landscape， park green space， and wetland landscape had the largest inundation area under different risk scenarios in the future， while the industrial landscape and commercial and public service landscape had the most severe economic losses from the perspective of inundation scope and economic losses. The areas with high landscape vulnerability in the short-term were mainly concentrated in Liwan District， Baiyun District and Huangpu District in the central part of Guangzhou from the perspective of the overall spatial distribution of vulnerability. In the medium and long term， the risk of landscape vulnerability in Haizhu District in the central part of Guangzhou gradually increased. From the perspective of spatial distribution of various landscape vulnerability， the most vulnerable areas of agricultural landscape in the short-term are Panyu District and Nansha District in southern Guangzhou compared with other landscapes including the transportation landscape and residential landscape. In the mid-term and long-term stages， the vulnerability risks of various landscapes have increased to varying degrees， with significant changes in the vulnerability levels of park green spaces and wetland landscapes. This article systematically assessed the impact of sea level rise combined with storm surge on different types of urban landscapes in Guangzhou. It will provide decision-making reference for the risk management and prevention of coastal disasters in the future， and the construction of urban resilience in Guangzhou.
In the context of global climate change and sea level rise， coastal disasters will have a significant impact on the landscape and socio-economic development of coastal cities. Guangzhou， a coastal city in the Pearl River Delta， was used to construct a “sensitivity adaptabilit” vulnerability assessment framework based on the land use and socio-economic data in the area. The vulnerability characteristics of urban landscape system in Guangzhou under three different scenarios of sea level rise superimposed with storm surge risk in the short-term （2030）， the medium-term （2050） and the long-term （2100） were assessed. The results showed that the agricultural landscape， park green space， and wetland landscape had the largest inundation area under different risk scenarios in the future， while the industrial landscape and commercial and public service landscape had the most severe economic losses from the perspective of inundation scope and economic losses. The areas with high landscape vulnerability in the short-term were mainly concentrated in Liwan District， Baiyun District and Huangpu District in the central part of Guangzhou from the perspective of the overall spatial distribution of vulnerability. In the medium and long term， the risk of landscape vulnerability in Haizhu District in the central part of Guangzhou gradually increased. From the perspective of spatial distribution of various landscape vulnerability， the most vulnerable areas of agricultural landscape in the short-term are Panyu District and Nansha District in southern Guangzhou compared with other landscapes including the transportation landscape and residential landscape. In the mid-term and long-term stages， the vulnerability risks of various landscapes have increased to varying degrees， with significant changes in the vulnerability levels of park green spaces and wetland landscapes. This article systematically assessed the impact of sea level rise combined with storm surge on different types of urban landscapes in Guangzhou. It will provide decision-making reference for the risk management and prevention of coastal disasters in the future， and the construction of urban resilience in Guangzhou.
2023,42(4):64-73
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.008
Abstract:
Quantitative analyses were conducted on the extreme temperatures and urban ecological spatial patterns with cooling effects in Wuhan in 2000， 2010， and 2020 by constructing indexes， functional models， and mathematical statistics to analyze the evolutionary characteristics of climate change and the cooling effect of urban ecological spatial pattern and the coordination mechanism between them. The results showed that the comprehensive index of extreme temperatures in Wuhan in 2000， 2010， and 2020 showed a trend of first increasing and then decreasing， while the overall index of urban ecological spatial pattern showed a trend of decreasing. The pattern indices including CA， NP， PLAND， LPI， LSI and AI， that were positively correlated with cooling effects， all exhibited linear or fluctuating decline characteristics within 20 years. It is indicated that the cooling effect of ecological space in Wuhan has gradually been weakened. The coordination degree between the comprehensive index of extreme temperature and the comprehensive index of urban ecological spatial pattern in 2000， 2010， and 2020 gradually decreased from intermediate coordination to severe imbalance， indicating that the cooling effect of ecological space in Wuhan on alleviating extreme temperature is gradually decreasing.
Quantitative analyses were conducted on the extreme temperatures and urban ecological spatial patterns with cooling effects in Wuhan in 2000， 2010， and 2020 by constructing indexes， functional models， and mathematical statistics to analyze the evolutionary characteristics of climate change and the cooling effect of urban ecological spatial pattern and the coordination mechanism between them. The results showed that the comprehensive index of extreme temperatures in Wuhan in 2000， 2010， and 2020 showed a trend of first increasing and then decreasing， while the overall index of urban ecological spatial pattern showed a trend of decreasing. The pattern indices including CA， NP， PLAND， LPI， LSI and AI， that were positively correlated with cooling effects， all exhibited linear or fluctuating decline characteristics within 20 years. It is indicated that the cooling effect of ecological space in Wuhan has gradually been weakened. The coordination degree between the comprehensive index of extreme temperature and the comprehensive index of urban ecological spatial pattern in 2000， 2010， and 2020 gradually decreased from intermediate coordination to severe imbalance， indicating that the cooling effect of ecological space in Wuhan on alleviating extreme temperature is gradually decreasing.
2023,42(4):74-85
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.009
Abstract:
Land use change is an important factor that affects the carbon cycle process of terrestrial systems and climate change.In order to seek the optimal carbon emission reduction path for terrestrial space and realize the optimization of low-carbon green national land spatial pattern，this study selected Wuhan as a case study area.Based on linear programming and Markov model，the land use structure of Wuhan in 2035 under different scenarios was formed.The cellular automata model incorporating spatial autocorrelation effect was used to simulate the land use spatial layout based on different land use structures，then the carbon emissions in the future under different land use structures and spatial layouts was analyzed，and finally a low-carbon land use pattern that meets the future development goals of the city was proposed.The results showed that in the natural development scenario and the economic priority scenario，the construction land and cultivated land area will change significantly，and the total carbon emissions will increase by 8.25% and 29.06%，respectively.Under the low-carbon oriented scenario，the growth rate of construction land slowed down，the forest land increased significantly，and the total carbon emissions increased by 5.46%.From the perspective of spatial form，under the natural development scenario and the economic priority scenario，the construction land expands outward around the central urban area obviously，and the scattered construction land in the far urban area was gradually merged.Under the low-carbon oriented scenario，the increase of construction land was limited，the increase of forest land in the far urban area was obvious，and the ecological framework of multi-ecological green wedges and ecological corridors was gradually formed.The above results showed that the simulation results under different scenarios can all show the impact of different development strategies on the territorial spatial pattern of Wuhan.The carbon emissions situation of the economic priority scenario that emphasizes the maximization of economic benefits is not optimistic.The new pattern of national land space development and protection integrated with the low-carbon concept can achieve the goal of green carbon reduction while taking into account the speed of economic growth.
Land use change is an important factor that affects the carbon cycle process of terrestrial systems and climate change.In order to seek the optimal carbon emission reduction path for terrestrial space and realize the optimization of low-carbon green national land spatial pattern，this study selected Wuhan as a case study area.Based on linear programming and Markov model，the land use structure of Wuhan in 2035 under different scenarios was formed.The cellular automata model incorporating spatial autocorrelation effect was used to simulate the land use spatial layout based on different land use structures，then the carbon emissions in the future under different land use structures and spatial layouts was analyzed，and finally a low-carbon land use pattern that meets the future development goals of the city was proposed.The results showed that in the natural development scenario and the economic priority scenario，the construction land and cultivated land area will change significantly，and the total carbon emissions will increase by 8.25% and 29.06%，respectively.Under the low-carbon oriented scenario，the growth rate of construction land slowed down，the forest land increased significantly，and the total carbon emissions increased by 5.46%.From the perspective of spatial form，under the natural development scenario and the economic priority scenario，the construction land expands outward around the central urban area obviously，and the scattered construction land in the far urban area was gradually merged.Under the low-carbon oriented scenario，the increase of construction land was limited，the increase of forest land in the far urban area was obvious，and the ecological framework of multi-ecological green wedges and ecological corridors was gradually formed.The above results showed that the simulation results under different scenarios can all show the impact of different development strategies on the territorial spatial pattern of Wuhan.The carbon emissions situation of the economic priority scenario that emphasizes the maximization of economic benefits is not optimistic.The new pattern of national land space development and protection integrated with the low-carbon concept can achieve the goal of green carbon reduction while taking into account the speed of economic growth.
2023,42(4):86-97
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.010
Abstract:
Global climate change has led to a gradual intensification of heat island effects and a significant increase in events of extreme high temperature at summer in urbans. How to effectively improve the cooling effect of urban blue-green spaces is an important way to adapt to the climate change and build a living environment with high-quality. The Landsat-8 data and radiative transfer equation was used to retrieve land surface temperature in Kunshan City. The correlation analysis and boosted regression tree （BRT） model of the urban blue-green spatial pattern and the measurement index of summer cooling effect were established constructed at the scale of urban and block to identify the key factors and their importance ranking of urban blue-green spatial patterns that affect summer cooling effects in the Jiangnan water network area and to explore the differences in spatial scale of cooling effect with comparative study. Results showed that there were four indicators with a relative contribution rate of over 10% for the impact of the blue-green spatial pattern on the summer maximum surface temperature at the scale of urban. The decreasing order of impact degree was as follows： index of water body shape > proportion of blue-green space > width of waterfront green space > aggregation index of water body. There were three indicators with a relative contribution rate of over 10% for the impact of the blue-green spatial pattern on the average intensity of cold island at the scale of urban. The decreasing order of impact degree was as follows： width of waterfront green space > index of water body shape > proportion of blue-green space. At the scale of block， there were five indicators with a relative contribution rate of over 10% for the impact of the blue-green spatial pattern on the summer maximum surface temperature at the scale of urban. The decreasing order of impact degree was as follows： index of water aggregation > average patch index of water > ratio of green space > ratio of water surface > index of water body shape. There were two indicators with a relative contribution rate of over 10% for the impact of the blue-green spatial pattern on the average intensity of cold island at the scale of urban. The decreasing order of impact degree was as follows： aggregation index of green space > proportion of blue-green space. It is indicated that the spatial pattern characteristics of urban blue-green space have significant scale effects on the correlation degree and contribution level of summer cooling. The optimization strategies of planning and design were proposed. It will provide a practical reference for creating a comfortable urban living environment at different scales.
Global climate change has led to a gradual intensification of heat island effects and a significant increase in events of extreme high temperature at summer in urbans. How to effectively improve the cooling effect of urban blue-green spaces is an important way to adapt to the climate change and build a living environment with high-quality. The Landsat-8 data and radiative transfer equation was used to retrieve land surface temperature in Kunshan City. The correlation analysis and boosted regression tree （BRT） model of the urban blue-green spatial pattern and the measurement index of summer cooling effect were established constructed at the scale of urban and block to identify the key factors and their importance ranking of urban blue-green spatial patterns that affect summer cooling effects in the Jiangnan water network area and to explore the differences in spatial scale of cooling effect with comparative study. Results showed that there were four indicators with a relative contribution rate of over 10% for the impact of the blue-green spatial pattern on the summer maximum surface temperature at the scale of urban. The decreasing order of impact degree was as follows： index of water body shape > proportion of blue-green space > width of waterfront green space > aggregation index of water body. There were three indicators with a relative contribution rate of over 10% for the impact of the blue-green spatial pattern on the average intensity of cold island at the scale of urban. The decreasing order of impact degree was as follows： width of waterfront green space > index of water body shape > proportion of blue-green space. At the scale of block， there were five indicators with a relative contribution rate of over 10% for the impact of the blue-green spatial pattern on the summer maximum surface temperature at the scale of urban. The decreasing order of impact degree was as follows： index of water aggregation > average patch index of water > ratio of green space > ratio of water surface > index of water body shape. There were two indicators with a relative contribution rate of over 10% for the impact of the blue-green spatial pattern on the average intensity of cold island at the scale of urban. The decreasing order of impact degree was as follows： aggregation index of green space > proportion of blue-green space. It is indicated that the spatial pattern characteristics of urban blue-green space have significant scale effects on the correlation degree and contribution level of summer cooling. The optimization strategies of planning and design were proposed. It will provide a practical reference for creating a comfortable urban living environment at different scales.
2023,42(4):98-106
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.011
Abstract:
The air temperature in the central urban area of Wuhan City was observed based on the local climate zone （LCZ） scheme to accurately evaluate the spatial-temporal differentiation characteristics of urban heat island （UHI） in Wuhan City and assist in the design of climate adaptability. The spatial-temporal variation of urban heat island intensity （UHII） in six types of architectural spaces and three types of natural spaces during three consecutive summer and winterperiods were analyzed. Explored the daily average UHII differences， hourly UHII variation， and UHII differences within the same LCZ type among different LCZ types， as well as their influencing factors were investigated. The results showed that each LCZ maintained stable daily average inter-type differences of UHII in summer and winter. The LCZ type with more high-rise building had a higher UHII， especially the open high-rise （LCZ 4） and open mid-rise （LCZ 5）. However， sparse forests （LCZ B）， dense forests （LCZ A）， open low-rise （LCZ 6）， and scattered buildings （LCZ 9） remained below 0 ℃ in general. There was a significant difference in the hourly variation of UHII between LCZ A and other LCZ types. LCZ A showed a rapid increase followed by a decrease within 8 hours after sunrise， while other LCZ types showed a rapid decrease followed by a stable increase. Within a single day， the UHII of each LCZ exhibited a characteristic of “strong in summer and weak in winter， weak in day and strong at night”. LCZ 9 and LCZ A were able to maintain the urban cold island effect for a long time to alleviate local heat environment， while LCZ 4 was the only type maintaining UHII above 0 ℃ in both summer and winter. Both LCZ 2 and LCZ 5 with mid-rise characteristics exhibited significant intra-type UHII differences. Similar LCZ plots located in the central part of the urban area were affected by the obstruction of urban canopy ventilation， and their UHII was higher than those on the urban boundary plots. The results indicated that UHII difference among LCZs were stable in summer and winter, while intra-class significant differences of the same LCZ were mainly driven by the spatial structure of Wuhan City, with densely urban core area being more prone to localized high temperatures due to poor ventilation performance and frequent anthropogenic heat emissions.
The air temperature in the central urban area of Wuhan City was observed based on the local climate zone （LCZ） scheme to accurately evaluate the spatial-temporal differentiation characteristics of urban heat island （UHI） in Wuhan City and assist in the design of climate adaptability. The spatial-temporal variation of urban heat island intensity （UHII） in six types of architectural spaces and three types of natural spaces during three consecutive summer and winterperiods were analyzed. Explored the daily average UHII differences， hourly UHII variation， and UHII differences within the same LCZ type among different LCZ types， as well as their influencing factors were investigated. The results showed that each LCZ maintained stable daily average inter-type differences of UHII in summer and winter. The LCZ type with more high-rise building had a higher UHII， especially the open high-rise （LCZ 4） and open mid-rise （LCZ 5）. However， sparse forests （LCZ B）， dense forests （LCZ A）， open low-rise （LCZ 6）， and scattered buildings （LCZ 9） remained below 0 ℃ in general. There was a significant difference in the hourly variation of UHII between LCZ A and other LCZ types. LCZ A showed a rapid increase followed by a decrease within 8 hours after sunrise， while other LCZ types showed a rapid decrease followed by a stable increase. Within a single day， the UHII of each LCZ exhibited a characteristic of “strong in summer and weak in winter， weak in day and strong at night”. LCZ 9 and LCZ A were able to maintain the urban cold island effect for a long time to alleviate local heat environment， while LCZ 4 was the only type maintaining UHII above 0 ℃ in both summer and winter. Both LCZ 2 and LCZ 5 with mid-rise characteristics exhibited significant intra-type UHII differences. Similar LCZ plots located in the central part of the urban area were affected by the obstruction of urban canopy ventilation， and their UHII was higher than those on the urban boundary plots. The results indicated that UHII difference among LCZs were stable in summer and winter, while intra-class significant differences of the same LCZ were mainly driven by the spatial structure of Wuhan City, with densely urban core area being more prone to localized high temperatures due to poor ventilation performance and frequent anthropogenic heat emissions.
2023,42(4):107-115
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.012
Abstract:
The observation data of the initial flowering period of Japanese cherry trees in the cherry blossom garden at Wuhan University and the meteorological data of the same period were used to analyze the temporal and spatial response characteristics of the flowering period of cherry blossoms to the urban heat island effect in Wuhan to improve the accuracy of the model for predicting the flowering period of cherry blossom in Wuhan and to better predict the flowering period of cherry blossom. The results showed that the urban heat island effect in Wuhan has been significantly enhanced since the late 1980s. The warming rate and contribution rate of urban heat island in winter have increased significantly since 1988. The urban heat island effect was the highest in the central urban areas of Wuhan， spreading and radiating from the urban core areas to the suburban areas. Huangpi and Xinzhou in the northern areas of Wuhan City were almost unaffected by the heat island effect. The flowering period of cherry blossom in Wuhan had obvious temporal and spatial response to the urban heat island effect in winter. The 5-year sliding average UHII of average winter temperature increased by 1 ℃， leading to an early flowering period of cherry blossoms by about 2.8 days. The Hankou River Beach， Holiday Inn Riverside and other places in the central urban areas of Wuhan were the first places where cherry blossoms bloomed， 1?2 days earlier than the flowering period of Wuhan University. The flowering period of cherry blossom garden in East Lake and Dijiao Park was 1?2 days later than that of Wuhan University. It is indicated that the urban heat island effect significantly advances the flowering period of cherry blossoms in Wuhan， and the flowering period of in the areas with strong urban heat island effect was earlier than that in the areas with weak urban heat island effect.
The observation data of the initial flowering period of Japanese cherry trees in the cherry blossom garden at Wuhan University and the meteorological data of the same period were used to analyze the temporal and spatial response characteristics of the flowering period of cherry blossoms to the urban heat island effect in Wuhan to improve the accuracy of the model for predicting the flowering period of cherry blossom in Wuhan and to better predict the flowering period of cherry blossom. The results showed that the urban heat island effect in Wuhan has been significantly enhanced since the late 1980s. The warming rate and contribution rate of urban heat island in winter have increased significantly since 1988. The urban heat island effect was the highest in the central urban areas of Wuhan， spreading and radiating from the urban core areas to the suburban areas. Huangpi and Xinzhou in the northern areas of Wuhan City were almost unaffected by the heat island effect. The flowering period of cherry blossom in Wuhan had obvious temporal and spatial response to the urban heat island effect in winter. The 5-year sliding average UHII of average winter temperature increased by 1 ℃， leading to an early flowering period of cherry blossoms by about 2.8 days. The Hankou River Beach， Holiday Inn Riverside and other places in the central urban areas of Wuhan were the first places where cherry blossoms bloomed， 1?2 days earlier than the flowering period of Wuhan University. The flowering period of cherry blossom garden in East Lake and Dijiao Park was 1?2 days later than that of Wuhan University. It is indicated that the urban heat island effect significantly advances the flowering period of cherry blossoms in Wuhan， and the flowering period of in the areas with strong urban heat island effect was earlier than that in the areas with weak urban heat island effect.
2023,42(4):116-124
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.013
Abstract:
To investigate whether differences in the representations of the two commonly used vegetation indices, NDVI and EVI, affect vegetation-related studies under different index representations. This study is based on the use of two different remote sensing vegetation indices, MODIS-NDVI and MODIS-EVI, from 2005 to 2020 to characterize the spatial features of vegetation in the Guangdong-Hong Kong-Macao Greater Bay Area. Using 17 natural and anthropogenic factors from the same time period as the driving factor, the effect of the 17 driving factors on the spatial features of the vegetation based on the different indices NDVI and EVI is calculated separately using Geo-detector. The results show that although there are differences in the results of the southern subtropical-tropical vegetation in the Guangdong-Hong Kong-Macao Greater Bay Area as characterized by different vegetation indices in NDVI and EVI, the quantitative and ranking results of the influence of driving factors under different indices calculated by the Geo-detector module are consistent, and are not affected by the differences in index representation. Among the drivers, land use type and elevation are the dominant drivers. Their effect on the spatial distribution of vegetation is greater than 50% under different metrics. Most of the factors have a two-factor enhancement effect on the spatial features of vegetation under different representation metrics. Synergies in population distribution and land use type have the strongest effect on NDVI-based vegetation cover; however, the synergistic effect of the population distribution and elevation has the strongest effect on the vegetation cover based on the EVI index. This study concludes that while the NDVI and EVI indices differ in representing vegetation cover characteristics, the results of the quantitative analysis of drivers remain consistent.
To investigate whether differences in the representations of the two commonly used vegetation indices, NDVI and EVI, affect vegetation-related studies under different index representations. This study is based on the use of two different remote sensing vegetation indices, MODIS-NDVI and MODIS-EVI, from 2005 to 2020 to characterize the spatial features of vegetation in the Guangdong-Hong Kong-Macao Greater Bay Area. Using 17 natural and anthropogenic factors from the same time period as the driving factor, the effect of the 17 driving factors on the spatial features of the vegetation based on the different indices NDVI and EVI is calculated separately using Geo-detector. The results show that although there are differences in the results of the southern subtropical-tropical vegetation in the Guangdong-Hong Kong-Macao Greater Bay Area as characterized by different vegetation indices in NDVI and EVI, the quantitative and ranking results of the influence of driving factors under different indices calculated by the Geo-detector module are consistent, and are not affected by the differences in index representation. Among the drivers, land use type and elevation are the dominant drivers. Their effect on the spatial distribution of vegetation is greater than 50% under different metrics. Most of the factors have a two-factor enhancement effect on the spatial features of vegetation under different representation metrics. Synergies in population distribution and land use type have the strongest effect on NDVI-based vegetation cover; however, the synergistic effect of the population distribution and elevation has the strongest effect on the vegetation cover based on the EVI index. This study concludes that while the NDVI and EVI indices differ in representing vegetation cover characteristics, the results of the quantitative analysis of drivers remain consistent.
2023,42(4):125-131
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.014
Abstract:
The conventional japonica rice and its Cry2A* transgenic rice lines， and the conventional indica rice and its Cry2A* transgenic rice lines were used to conduct the pot experiment. The root characteristics of Cry2A*transgenic rice lines under nitrogen application and no nitrogen application were investigated to study the root characteristics of Cry2A* transgenic rice lines and provide technical support for the cultivation and regulation of insect-resistant transgenic rice. The results showed that the root length， root surface area and root volume of the Cry2A* transgenic rice lines were significantly lower than those of the parents under no nitrogen application at the stage of mature， but there was no significant difference between them and the parental control under the nitrogen application. The root active absorption area of KY（Cry2A*） was significantly higher than that of the parents at the stage of flowering， while the root active absorption area of MH86（Cry2A*） was not significantly different from that of the parents. Compared with no nitrogen application， nitrogen application significantly increased the root diameter of KY（Cry2A*）， but had no significant effect on the root diameter of MH86（Cry2A*）. It is indicated that there was a certain difference in the root characteristics between the Cry2A* transgenic rice and its parents， and this difference was more obvious under no nitrogen application.
The conventional japonica rice and its Cry2A* transgenic rice lines， and the conventional indica rice and its Cry2A* transgenic rice lines were used to conduct the pot experiment. The root characteristics of Cry2A*transgenic rice lines under nitrogen application and no nitrogen application were investigated to study the root characteristics of Cry2A* transgenic rice lines and provide technical support for the cultivation and regulation of insect-resistant transgenic rice. The results showed that the root length， root surface area and root volume of the Cry2A* transgenic rice lines were significantly lower than those of the parents under no nitrogen application at the stage of mature， but there was no significant difference between them and the parental control under the nitrogen application. The root active absorption area of KY（Cry2A*） was significantly higher than that of the parents at the stage of flowering， while the root active absorption area of MH86（Cry2A*） was not significantly different from that of the parents. Compared with no nitrogen application， nitrogen application significantly increased the root diameter of KY（Cry2A*）， but had no significant effect on the root diameter of MH86（Cry2A*）. It is indicated that there was a certain difference in the root characteristics between the Cry2A* transgenic rice and its parents， and this difference was more obvious under no nitrogen application.
2023,42(4):132-139
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.015
Abstract:
After sowing winter wheat from 2018 to 2020， the cotton stalk was mechanically crushed and covered before returning to the field to study the decomposition dynamics of cotton stalk returning to the field and the impact of different amounts of cotton stalk returning to the field on the yield of wheat. Three treatments including zero stalk returning （ZS）， half stalk returning （HS） and all stalk returning （AS） were set up with the randomized block. The decomposition， nutrient release， and structural component changes of cotton straw with different returning amounts were analyzed. The results showed that the decomposition rate of straw was first fast and then slow， with the fastest decomposition occurring 20 days after returning to the field， and then gradually decreasing. After 170 days of returning to the field， the decomposition rates of HS and AS were 73.4% and 66.8% respectively from 2018 to 2019， and 77.6% and 60.4% respectively from 2019 to 2020. There were differences in the release rates of different structural components in straw. After 170 days of decomposition， the release rate of soluble sugars in cotton culms was 70.7%-81.38%， followed by cellulose （57.3%-60.7%） and lignin （44.1%-50.3%）. There were also differences in the release rates of N， P， and K in cotton stalk， with K release rates ranging from 83.1% to 87.9%， P release rates ranging from 71.4% to 80.5%， and N release rates ranging from 66.5% to 74.7%. Returning cotton stalk to the field increased the number of spikes per unit area of wheat， thereby increasing the yield of wheat. It is indicated that returning cotton stalk to the field is beneficial for improving soil nutrient status and increasing the yield of winter crop （wheat）， with all stalk returning （AS） being better.
After sowing winter wheat from 2018 to 2020， the cotton stalk was mechanically crushed and covered before returning to the field to study the decomposition dynamics of cotton stalk returning to the field and the impact of different amounts of cotton stalk returning to the field on the yield of wheat. Three treatments including zero stalk returning （ZS）， half stalk returning （HS） and all stalk returning （AS） were set up with the randomized block. The decomposition， nutrient release， and structural component changes of cotton straw with different returning amounts were analyzed. The results showed that the decomposition rate of straw was first fast and then slow， with the fastest decomposition occurring 20 days after returning to the field， and then gradually decreasing. After 170 days of returning to the field， the decomposition rates of HS and AS were 73.4% and 66.8% respectively from 2018 to 2019， and 77.6% and 60.4% respectively from 2019 to 2020. There were differences in the release rates of different structural components in straw. After 170 days of decomposition， the release rate of soluble sugars in cotton culms was 70.7%-81.38%， followed by cellulose （57.3%-60.7%） and lignin （44.1%-50.3%）. There were also differences in the release rates of N， P， and K in cotton stalk， with K release rates ranging from 83.1% to 87.9%， P release rates ranging from 71.4% to 80.5%， and N release rates ranging from 66.5% to 74.7%. Returning cotton stalk to the field increased the number of spikes per unit area of wheat， thereby increasing the yield of wheat. It is indicated that returning cotton stalk to the field is beneficial for improving soil nutrient status and increasing the yield of winter crop （wheat）， with all stalk returning （AS） being better.
2023,42(4):140-149
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.016
Abstract:
A questionnaire survey was conducted on 306 planting entities in main citrus planting provinces （cities） in China regarding techniques including winter sanitation，weed control，and management of fertilizer and water to understand the cultivation situation and management techniques of citrus in China.The results showed that 96.7% of planting entities conducted winter sanitation for citrus orchards.The annual average times of weed control，fertilization，irrigation and pesticide application were 3.2，4.9，6.7 and 11.5，respectively.57.5%，56.2%，and 47.4% of the planters used herbicides，knapsack mowers，and manual weed control，respectively.65.5% and 63.9% of the planters used broadcasting and foliar spraying methods.53.1% and 39.3% of the planters used pipe irrigation and drip irrigation methods.71.2% of the planters used pipeline injection，and the proportion of air-sent mechanical injection was relatively low （14.7%）.Only 34.5% of the planters had regular pruning during the growing season，and the pruning was mainly done by manual methods （accounting for 86.6%）.The application of citrus cultivation and management techniques is related to the area，type，and distribution of citrus orchards.The annual average number of weed control and fertilization，the proportion of drip irrigation and fertilization，is higher in large area or gentle slope flat orchards than that in small area or mountainous orchards，but the annual average number of pesticide applications is the opposite.In central China，the ratio of irrigation，fertilization and fruit holding operation at maturity were the least among different planting regions.Based on the results of investigation，suggestions for the development of citrus cultivation and management technologies have been proposed.Firstly，it is necessary to continue to pay attention to the research and development of citrus cultivation and management technologies that meet the needs of the times.Secondly，it is important to attach importance to the research and development of cultivation technologies and equipment that combine agronomy and agricultural machinery.Thirdly，the research and development of cultivation technologies and equipment with ease，simplicity and high quality should focus on systematicity.
A questionnaire survey was conducted on 306 planting entities in main citrus planting provinces （cities） in China regarding techniques including winter sanitation，weed control，and management of fertilizer and water to understand the cultivation situation and management techniques of citrus in China.The results showed that 96.7% of planting entities conducted winter sanitation for citrus orchards.The annual average times of weed control，fertilization，irrigation and pesticide application were 3.2，4.9，6.7 and 11.5，respectively.57.5%，56.2%，and 47.4% of the planters used herbicides，knapsack mowers，and manual weed control，respectively.65.5% and 63.9% of the planters used broadcasting and foliar spraying methods.53.1% and 39.3% of the planters used pipe irrigation and drip irrigation methods.71.2% of the planters used pipeline injection，and the proportion of air-sent mechanical injection was relatively low （14.7%）.Only 34.5% of the planters had regular pruning during the growing season，and the pruning was mainly done by manual methods （accounting for 86.6%）.The application of citrus cultivation and management techniques is related to the area，type，and distribution of citrus orchards.The annual average number of weed control and fertilization，the proportion of drip irrigation and fertilization，is higher in large area or gentle slope flat orchards than that in small area or mountainous orchards，but the annual average number of pesticide applications is the opposite.In central China，the ratio of irrigation，fertilization and fruit holding operation at maturity were the least among different planting regions.Based on the results of investigation，suggestions for the development of citrus cultivation and management technologies have been proposed.Firstly，it is necessary to continue to pay attention to the research and development of citrus cultivation and management technologies that meet the needs of the times.Secondly，it is important to attach importance to the research and development of cultivation technologies and equipment that combine agronomy and agricultural machinery.Thirdly，the research and development of cultivation technologies and equipment with ease，simplicity and high quality should focus on systematicity.
2023,42(4):150-157
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.017
Abstract:
To screen the rootstock resources for superior traits of convergent parents，94 individual plants of F1 hybrid population with Red tangerine as the female parent and Trifoliate orange as the male parent were used as test materials to observe their defoliation period and flowering period for two consecutive years，and the fruit quality，seed embryo types and germination rate of 37 individual plants with high fruition rates were analyzed. The results showed that the phenology of 94 individual plants was similar to that of their parents，but there was a significant difference in the defoliation period between hybrid progenies. The fruit shape of the hybrid population was more inclined toward paternal inheritance，mainly oval in shape. The average fruit weight of the offspring populations was 58.63 g，average number of seeds was 14，and 1000-grain weight was 153.73 g.The soluble solid content was 10.7%?16.5%，which was not significantly different from that of the female parent，and the titratable acid content of fruit was 2.00%?5.56%，which was significantly higher than that of the female parent. The flavedo of the hybrid population mainly includes red peel （female parent preferred） and yellow peel （male parent preferred）. The contents of β-cryptoxanthin were significantly higher than those of the parents，and the contents of violaxanthin lutein and zeaxanthin were between those of parents，while the contents of β-carotene in the peel of parents and hybrid offspring were relatively low. The contents of violaxanthin，lutein and β-carotene showed continuous changes，which showed quantitative characteristics. The ratio of monoembryoid to polyembryoid types in the hybrid progeny was close to 1∶3，which indicated that the character was determined by a single gene. In summary，the results showed that the progeny No. 3，No. 6 and No. 24 had the characteristics of polyembryony ，more seeds per fruit and a high germination rate，and could be used as excellent rootstock candidates for further evaluation.
To screen the rootstock resources for superior traits of convergent parents，94 individual plants of F1 hybrid population with Red tangerine as the female parent and Trifoliate orange as the male parent were used as test materials to observe their defoliation period and flowering period for two consecutive years，and the fruit quality，seed embryo types and germination rate of 37 individual plants with high fruition rates were analyzed. The results showed that the phenology of 94 individual plants was similar to that of their parents，but there was a significant difference in the defoliation period between hybrid progenies. The fruit shape of the hybrid population was more inclined toward paternal inheritance，mainly oval in shape. The average fruit weight of the offspring populations was 58.63 g，average number of seeds was 14，and 1000-grain weight was 153.73 g.The soluble solid content was 10.7%?16.5%，which was not significantly different from that of the female parent，and the titratable acid content of fruit was 2.00%?5.56%，which was significantly higher than that of the female parent. The flavedo of the hybrid population mainly includes red peel （female parent preferred） and yellow peel （male parent preferred）. The contents of β-cryptoxanthin were significantly higher than those of the parents，and the contents of violaxanthin lutein and zeaxanthin were between those of parents，while the contents of β-carotene in the peel of parents and hybrid offspring were relatively low. The contents of violaxanthin，lutein and β-carotene showed continuous changes，which showed quantitative characteristics. The ratio of monoembryoid to polyembryoid types in the hybrid progeny was close to 1∶3，which indicated that the character was determined by a single gene. In summary，the results showed that the progeny No. 3，No. 6 and No. 24 had the characteristics of polyembryony ，more seeds per fruit and a high germination rate，and could be used as excellent rootstock candidates for further evaluation.
LI Dasui, RUAN Siqi, HU Qingqing, ZHANG Jinzhi, ZHANG Yahao, DIAN Yuanyong, HU Chungen, LIU Yongzhong, LEI Hongwei, ZHOU Jingjing
2023,42(4):158-166
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.018
Abstract:
One hundred and twenty citrus trees under three cultivation patterns including wide row and narrow plant，wide row and narrow plant fence pattern and traditional cultivation were used to measure the content of nitrogen in the canopy and extract the texture index and vegetation index from the multispectral images data of UAV remote sensing to quickly and accurately obtain the content of nitrogen and spatial distribution characteristics of plant canopy，and to manage the large-scale orchard accurately and dynamically.The random forest （RF） algorithm was used to establish the inversion model of nitrogen in the citrus canopy based on vegetation index，texture index，and the integration of vegetation index and texture index.The inversion accuracy of support vector machine （SVM），BP neural network algorithm （BP），and RF models that integrate vegetation index and texture index was compared.The results showed that the integration of vegetation index and texture index predicted the content of nitrogen in citrus canopy more accurately than the single vegetation index or texture index in the random forest algorithm.The training sets R2 and the test sets R2 of the vegetation index，texture index，and integration of vegetation index and texture index were0.710 and 0.430，0.761 and 0.349，0.775 and 0.533，respectively.The training sets R2 and the test sets R2 of the integration of vegetation index and texture index in the SVM algorithm and BP neural network were0.511 and 0.371，0.651 and 0.204，respectively.The results of using the RF model of vegetation index and texture index to inverse the content of nitrogen in citrus orchards under three cultivation patterns showed that the average content of nitrogen in citrus canopy in wide row and narrow plant werethe highest，followed by the wide row and narrow plant fence pattern，and the traditional cultivation pattern was the lowest，with the average content of nitrogen being 31.33，30.20，and 27.82 mg/g，respectively.It is indicated that the random forest algorithm combining UAV remote sensing with vegetation index and texture index can effectively predict the content of nitrogen in citrus canopy.It will provide a reference for the quantitative fertilization of large-scale citrus orchards.
One hundred and twenty citrus trees under three cultivation patterns including wide row and narrow plant，wide row and narrow plant fence pattern and traditional cultivation were used to measure the content of nitrogen in the canopy and extract the texture index and vegetation index from the multispectral images data of UAV remote sensing to quickly and accurately obtain the content of nitrogen and spatial distribution characteristics of plant canopy，and to manage the large-scale orchard accurately and dynamically.The random forest （RF） algorithm was used to establish the inversion model of nitrogen in the citrus canopy based on vegetation index，texture index，and the integration of vegetation index and texture index.The inversion accuracy of support vector machine （SVM），BP neural network algorithm （BP），and RF models that integrate vegetation index and texture index was compared.The results showed that the integration of vegetation index and texture index predicted the content of nitrogen in citrus canopy more accurately than the single vegetation index or texture index in the random forest algorithm.The training sets R2 and the test sets R2 of the vegetation index，texture index，and integration of vegetation index and texture index were0.710 and 0.430，0.761 and 0.349，0.775 and 0.533，respectively.The training sets R2 and the test sets R2 of the integration of vegetation index and texture index in the SVM algorithm and BP neural network were0.511 and 0.371，0.651 and 0.204，respectively.The results of using the RF model of vegetation index and texture index to inverse the content of nitrogen in citrus orchards under three cultivation patterns showed that the average content of nitrogen in citrus canopy in wide row and narrow plant werethe highest，followed by the wide row and narrow plant fence pattern，and the traditional cultivation pattern was the lowest，with the average content of nitrogen being 31.33，30.20，and 27.82 mg/g，respectively.It is indicated that the random forest algorithm combining UAV remote sensing with vegetation index and texture index can effectively predict the content of nitrogen in citrus canopy.It will provide a reference for the quantitative fertilization of large-scale citrus orchards.
2023,42(4):167-176
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.019
Abstract:
The slow/controlled-release technology has been widely applied in the agricultural production with the rapid development of green， efficient， and intensive modern agriculture.The use of slow/controlled release fertilizers （SRFs or CRFs） can reduce environmental pollution， restore soil ecology， improve the utilization efficiency of fertilizer， and reduce labor costs.However， there are also some shortcomings in the application of slow/controlled release fertilizers.This article summarized the development， classification， preparation methods， and applications of SRFs or CRFs in recent years based on reviewing literatures.The advantages and disadvantages of slow/controlled release fertilizers in application were summarized.The problems and countermeasures in the application of slow/controlled release fertilizers were sorted out.It is proposed that systematic studies should be conducted on the application technology and evaluation system of slow/controlled release fertilizers in the future， focusing on the development of green materials， production processes， and equipment innovation， to form the integration and demonstration of industrial technology for slow/controlled release fertilizers， and to develop efficient， environment friendly， and low-cost slow/controlled release fertilizers that meet the requirements of production.
The slow/controlled-release technology has been widely applied in the agricultural production with the rapid development of green， efficient， and intensive modern agriculture.The use of slow/controlled release fertilizers （SRFs or CRFs） can reduce environmental pollution， restore soil ecology， improve the utilization efficiency of fertilizer， and reduce labor costs.However， there are also some shortcomings in the application of slow/controlled release fertilizers.This article summarized the development， classification， preparation methods， and applications of SRFs or CRFs in recent years based on reviewing literatures.The advantages and disadvantages of slow/controlled release fertilizers in application were summarized.The problems and countermeasures in the application of slow/controlled release fertilizers were sorted out.It is proposed that systematic studies should be conducted on the application technology and evaluation system of slow/controlled release fertilizers in the future， focusing on the development of green materials， production processes， and equipment innovation， to form the integration and demonstration of industrial technology for slow/controlled release fertilizers， and to develop efficient， environment friendly， and low-cost slow/controlled release fertilizers that meet the requirements of production.
2023,42(4):177-184
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.020
Abstract:
A pot experiment was designed to plant winter crops in the Science and Technology Park of Jiangxi Agricultural University from 2020 to 2021 to study the interaction mechanism between root exudates and the changes of soil microbial community under the intercropping pattern of Chinese milkvetch （Leguminous cruciferous） and rapeseed .The results showed that there were significant differences in the characteristics of root exudates under different planting patterns of Chinese milkvetch and rapeseed compared with the single cropping of Chinese milkvetch， intercropping significantly increased the content of monosaccharides and decreased the content of neurotransmitter compounds. Amino acids， monosaccharides， neurotransmitters， and other compounds were significantly correlated with soil microorganisms. Among them， monosaccharide compounds were significantly positively correlated with Acidobacteriota， Chloroflexi and other microorganisms.Neurotransmitter compounds were significantly positively correlated with Chloroflexota， Firmicutes， Gemmatimonadota， Myxococcota， Cyanobacteria and other microorganisms. The individual correlation results of the three models including the single cropping of Chinese milkvetch （A）， the single cropping of rapeseed （R）， and the intercropping of Chinese milkvetch and rapeseed oil （AR） showed that the difference in the correlation between root exudates and microorganisms and the overall result was the maximum under the single cropping of rapeseed.There was no significant correlation between monosaccharides and Acidobacterium and Chlorobacterium under A and R. Under AR， there was a significantly positive correlation between monosaccharides and Acidobacterium and Chlorobacterium. The relative abundance of Acidobacteriota communities under AR was significantly higher than that under A， and the index of microbial coverage was also significantly higher than that under A. It is indicated that root exudates are likely to be an important factor in changing the structure of soil microbial community in the intercropping of Chinese milkvetch and rapeseed， and monosaccharide compounds play a major role in this process.
A pot experiment was designed to plant winter crops in the Science and Technology Park of Jiangxi Agricultural University from 2020 to 2021 to study the interaction mechanism between root exudates and the changes of soil microbial community under the intercropping pattern of Chinese milkvetch （Leguminous cruciferous） and rapeseed .The results showed that there were significant differences in the characteristics of root exudates under different planting patterns of Chinese milkvetch and rapeseed compared with the single cropping of Chinese milkvetch， intercropping significantly increased the content of monosaccharides and decreased the content of neurotransmitter compounds. Amino acids， monosaccharides， neurotransmitters， and other compounds were significantly correlated with soil microorganisms. Among them， monosaccharide compounds were significantly positively correlated with Acidobacteriota， Chloroflexi and other microorganisms.Neurotransmitter compounds were significantly positively correlated with Chloroflexota， Firmicutes， Gemmatimonadota， Myxococcota， Cyanobacteria and other microorganisms. The individual correlation results of the three models including the single cropping of Chinese milkvetch （A）， the single cropping of rapeseed （R）， and the intercropping of Chinese milkvetch and rapeseed oil （AR） showed that the difference in the correlation between root exudates and microorganisms and the overall result was the maximum under the single cropping of rapeseed.There was no significant correlation between monosaccharides and Acidobacterium and Chlorobacterium under A and R. Under AR， there was a significantly positive correlation between monosaccharides and Acidobacterium and Chlorobacterium. The relative abundance of Acidobacteriota communities under AR was significantly higher than that under A， and the index of microbial coverage was also significantly higher than that under A. It is indicated that root exudates are likely to be an important factor in changing the structure of soil microbial community in the intercropping of Chinese milkvetch and rapeseed， and monosaccharide compounds play a major role in this process.
2023,42(4):185-191
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.021
Abstract:
A soil culture experiment was conducted to study the effects of two sulfur fertilizers including sulfur and sodium sulfate combined with calcium magnesium phosphate on the changes in Cd availability and the transformation of Cd morphology in paddy soil to investigate the immobilization effect of sulfur fertilizer combined with phosphorus fertilizer on cadmium （Cd） in paddy soil. Six treatments including control （CK）， calcium magnesium phosphate （P）， sulfur （S1）， sodium sulfate （S2）， calcium magnesium phosphate + sulfur （PS1）， and calcium magnesium phosphate + sodium sulfate （PS2） were set up. The relationship between the Cd availability in soil and the available sulfur， available phosphorus， pH， and Eh was analyzed. The results showed that the Cd availability in soil decreased significantly after applying different immobilization materials in the soil. Among them， PS1 treatment had the lowest content of available Cd， which decreased by 49.8% compared to CK. P treatment increased soil pH by 0.39 compared to CK. S1 treatment significantly reduced the soil Eh value， which was 23.2% lower than CK， and promoted the reduction of SO42- to S2-. PS1 treatment significantly increased the content of available phosphorus in soil. Compared with CK， the available phosphorus in PS1 treatment increased by 81.9%. PS1 treatment synergistically promoted the Cd transformation of exchangeable fraction to residual fraction in soil due to the regulation of soil Eh， available sulfur and available phosphorus. It is indicated that the combination application of sulfur and calcium magnesium phosphate has potential in alleviating Cd pollution in paddy soil.
A soil culture experiment was conducted to study the effects of two sulfur fertilizers including sulfur and sodium sulfate combined with calcium magnesium phosphate on the changes in Cd availability and the transformation of Cd morphology in paddy soil to investigate the immobilization effect of sulfur fertilizer combined with phosphorus fertilizer on cadmium （Cd） in paddy soil. Six treatments including control （CK）， calcium magnesium phosphate （P）， sulfur （S1）， sodium sulfate （S2）， calcium magnesium phosphate + sulfur （PS1）， and calcium magnesium phosphate + sodium sulfate （PS2） were set up. The relationship between the Cd availability in soil and the available sulfur， available phosphorus， pH， and Eh was analyzed. The results showed that the Cd availability in soil decreased significantly after applying different immobilization materials in the soil. Among them， PS1 treatment had the lowest content of available Cd， which decreased by 49.8% compared to CK. P treatment increased soil pH by 0.39 compared to CK. S1 treatment significantly reduced the soil Eh value， which was 23.2% lower than CK， and promoted the reduction of SO42- to S2-. PS1 treatment significantly increased the content of available phosphorus in soil. Compared with CK， the available phosphorus in PS1 treatment increased by 81.9%. PS1 treatment synergistically promoted the Cd transformation of exchangeable fraction to residual fraction in soil due to the regulation of soil Eh， available sulfur and available phosphorus. It is indicated that the combination application of sulfur and calcium magnesium phosphate has potential in alleviating Cd pollution in paddy soil.
2023,42(4):192-198
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.022
Abstract:
By analyzing and predicting the changes in soil organic carbon content of maize fields in Qianqiaozi Village，Huairou District，we reveal the key influencing factors affecting organic carbon changes and provide a scientific basis for achieving carbon sequestration and emission reduction targets in Beijing，China. In this study，the DNDC model was validated using the actual measured organic carbon data from 2016 to 2019 in the maize fields，and then the main influencing factors such as climate，soil and material return were selected to conduct sensitivity analysis on the validated DNDC model，and finally the future （to 2100） organic carbon changes under different typical concentration pathways （RCP8.5，RCP4.5） were simulated. The results showed that： the calibrated DNDC model can simulate the soil organic carbon changes in this maize field well； the initial organic carbon content and straw return rate are the main influencing factors of organic carbon changes； the organic carbon content increases significantly under RCP8.5 and RCP4.5，and the soil carbon pool reaches equilibrium at about 77 years，and the organic carbon content reaches 27.70 g/kg and 29.03 g/kg by 2100，respectively. The DNDC model can be used to study organic carbon changes in maize fields in this study area，and this management approach can be used to sustain carbon sequestration in the future.
By analyzing and predicting the changes in soil organic carbon content of maize fields in Qianqiaozi Village，Huairou District，we reveal the key influencing factors affecting organic carbon changes and provide a scientific basis for achieving carbon sequestration and emission reduction targets in Beijing，China. In this study，the DNDC model was validated using the actual measured organic carbon data from 2016 to 2019 in the maize fields，and then the main influencing factors such as climate，soil and material return were selected to conduct sensitivity analysis on the validated DNDC model，and finally the future （to 2100） organic carbon changes under different typical concentration pathways （RCP8.5，RCP4.5） were simulated. The results showed that： the calibrated DNDC model can simulate the soil organic carbon changes in this maize field well； the initial organic carbon content and straw return rate are the main influencing factors of organic carbon changes； the organic carbon content increases significantly under RCP8.5 and RCP4.5，and the soil carbon pool reaches equilibrium at about 77 years，and the organic carbon content reaches 27.70 g/kg and 29.03 g/kg by 2100，respectively. The DNDC model can be used to study organic carbon changes in maize fields in this study area，and this management approach can be used to sustain carbon sequestration in the future.
2023,42(4):199-206
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.023
Abstract:
In order to investigate the regulatory mechanisms of the interferon-induced transmembrane protein 1 gene （Ifitm1） in mammalian follicle development， Ifitm1 was overexpressed and suppressed in mouse granulosa cells （mGCs）. The effects of Ifitm1 on the growth of mGCs were detected by flow cytometry， qRT-PCR and EdU method， the effects of Ifitm1 on the expression of ovulation-related genes in mice were detected by qRT-PCR and Western blot， and the mGCs were treated with related pathway inhibitors to investigate the mechanisms by which Ifitm1 affectes follicle development and ovulation in mice. The results showed that the Ifitm1 gene was successfully overexpressed and suppressed in mGCs. Further studies revealed that interference with Ifitm1 gene expression reduced the expression of cell cycle protein Ccnd1 by 63.5%， decreased the percentage of cells in G0/G1 phase， blocked the cells in G2/M phase， thus inhibiting the proliferation of granulosa cell. Ifitm1 interference also resulted in 1.95-6.76 fold increase in the expression levels of the ovulation marker genes Lhr， Ereg and Cyp19a1 （P<0.05）， and inhibited the expression of p-AKT （Ser473）， a key protein in the PI3K/AKT signalling pathway， blocked the PI3K/AKT signalling pathway， and then inhibited the expression of Ifitm1 gene， but the mRNA levels of Lhr， Ereg and Cyp19a1 remained unchanged in mGCs， suggesting that the Ifitm1 gene affects ovulation through inhibiting the activity of PI3K/AKT signalling pathway. In summary， Ifitm1 plays an important role in mGC growth and follicular ovulation through the PI3K/AKT pathway.
In order to investigate the regulatory mechanisms of the interferon-induced transmembrane protein 1 gene （Ifitm1） in mammalian follicle development， Ifitm1 was overexpressed and suppressed in mouse granulosa cells （mGCs）. The effects of Ifitm1 on the growth of mGCs were detected by flow cytometry， qRT-PCR and EdU method， the effects of Ifitm1 on the expression of ovulation-related genes in mice were detected by qRT-PCR and Western blot， and the mGCs were treated with related pathway inhibitors to investigate the mechanisms by which Ifitm1 affectes follicle development and ovulation in mice. The results showed that the Ifitm1 gene was successfully overexpressed and suppressed in mGCs. Further studies revealed that interference with Ifitm1 gene expression reduced the expression of cell cycle protein Ccnd1 by 63.5%， decreased the percentage of cells in G0/G1 phase， blocked the cells in G2/M phase， thus inhibiting the proliferation of granulosa cell. Ifitm1 interference also resulted in 1.95-6.76 fold increase in the expression levels of the ovulation marker genes Lhr， Ereg and Cyp19a1 （P<0.05）， and inhibited the expression of p-AKT （Ser473）， a key protein in the PI3K/AKT signalling pathway， blocked the PI3K/AKT signalling pathway， and then inhibited the expression of Ifitm1 gene， but the mRNA levels of Lhr， Ereg and Cyp19a1 remained unchanged in mGCs， suggesting that the Ifitm1 gene affects ovulation through inhibiting the activity of PI3K/AKT signalling pathway. In summary， Ifitm1 plays an important role in mGC growth and follicular ovulation through the PI3K/AKT pathway.
2023,42(4):207-214
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.024
Abstract:
In order to explore the optimum spectrum for largemouth bass （Micropterus salmoides） larvae，four treatments including full spectrum （FS），red light （RL），green light （GL） and blue light （BL） were set up under the industrial recirculating aquaculture system. Hoping to find suitable spectral range for largemouth bass breeding，the growth performance，activities of superoxide dismutase （SOD），catalase （CAT），lysozyme （LZM），alkaline phosphatase （AKP），contents of glutathione （GSH） and malondialdehyde （MDA），the relative expression levels of growth hormone （gh），insulin-like growth factors-1 （igf-1），thyroid stimulating hormone （tsh），heat shock protein 70 （hsp70），corticotropin releasing factor （crf），caspase-3 of largemouth bass larvae in different treatments were compared and analyzed. The results showed that the final body length and weight，specific growth rate （SGR），weight gain rate （WGR） and LZM activity of larvae in the full spectrum，green light and blue light groups were significantly higher than those in the red light group （P<0.05），while the contents of MDA，GSH and activities of SOD and CAT were significantly lower than those of the red light group （P<0.05）. The activity of AKP and mRNA expressions of gh，igf-1 and tsh in the full spectrum and green light groups were significantly higher than those in the red light group （P<0.05），and the mRNA expressions of hsp70，crf and caspase-3 were significantly lower than those of the red and blue light groups （P<0.05）. The survival rate （SR） of larvae in the full spectrum group was significantly higher than that in other groups （P<0.05），and showed good cluster phototaxis behavior. In conclusion，full spectrum light source is the most beneficial for largemouth bass larvae cultivation under the industrial recirculating aquaculture.
In order to explore the optimum spectrum for largemouth bass （Micropterus salmoides） larvae，four treatments including full spectrum （FS），red light （RL），green light （GL） and blue light （BL） were set up under the industrial recirculating aquaculture system. Hoping to find suitable spectral range for largemouth bass breeding，the growth performance，activities of superoxide dismutase （SOD），catalase （CAT），lysozyme （LZM），alkaline phosphatase （AKP），contents of glutathione （GSH） and malondialdehyde （MDA），the relative expression levels of growth hormone （gh），insulin-like growth factors-1 （igf-1），thyroid stimulating hormone （tsh），heat shock protein 70 （hsp70），corticotropin releasing factor （crf），caspase-3 of largemouth bass larvae in different treatments were compared and analyzed. The results showed that the final body length and weight，specific growth rate （SGR），weight gain rate （WGR） and LZM activity of larvae in the full spectrum，green light and blue light groups were significantly higher than those in the red light group （P<0.05），while the contents of MDA，GSH and activities of SOD and CAT were significantly lower than those of the red light group （P<0.05）. The activity of AKP and mRNA expressions of gh，igf-1 and tsh in the full spectrum and green light groups were significantly higher than those in the red light group （P<0.05），and the mRNA expressions of hsp70，crf and caspase-3 were significantly lower than those of the red and blue light groups （P<0.05）. The survival rate （SR） of larvae in the full spectrum group was significantly higher than that in other groups （P<0.05），and showed good cluster phototaxis behavior. In conclusion，full spectrum light source is the most beneficial for largemouth bass larvae cultivation under the industrial recirculating aquaculture.
2023,42(4):215-224
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.025
Abstract:
To determine the dietary protein requirement of mandarin fish （Siniperca chuatsi） with different sizes，mandarin fish with initial body weight of （11.58±1.34） g （G1），（94.77±2.59） g （G2） and （245.26±3.59） g （G3） were selected to investigate the effects of different dietary protein levels on growth performance，feed utilization rate，morphological indexes，digestive enzyme activity，antioxidant capacity and ammonia nitrogen excretion.The results showed that when the protein content was 500 g/kg，the specific growth rate （SGR），final body weight （FBW） and weight gain rate （WGR） of mandarin fish in G1 and G2 groups were the highest，while when the protein content was 450 g/kg，those in group G3 were the highest.The feed coefficient showed an opposite trend.Based on the analysis of SGR’s broken-line regression model，the optimal protein requirements of three different sizes of mandarin fish were 497.1 g/kg，451.9 g/kg and 446 g/kg，respectively.The survival rate of mandarin fish with small and middle sizes fed with low protein level （350 g/kg and 400 g/kg） diet was significantly lower than that of other groups （P<0.05），but dietary protein level had no significant effect on survival rate of mandarin fish in G3 group （P>0.05）.Condition factor，hepotasomatic index and viscerasomatic index of mandarin fish in G1 and G2 groups decreased significantly with the increase of dietary protein level （P<0.05）.With the increase of dietary protein level，the dry matter apparent digestibility coefficient （ADC） of mandarin fish was first increased and then stabilized in G1 and G3 groups，while that in G2 group was first increased and then decreased.With the increase of dietary protein level，the crude protein ADC of mandarin fish with three different sizes increased significantly （P<0.05） and decreased slightly after reaching the highest value at 500 g/kg protein level.A similar trend was observed in trypsin activity of the foregut.The activities of glutamic-pyruvic transaminase and glutamic-oxalacetic transaminase in liver of mandarin fish at three different growth stages increased dramatically as dietary protein level elevated （P<0.05）.The ammonia nitrogen excretion rate of mandarin fish with three different sizes reached the peak at 6 h after feeding and increased significantly with the increase of dietary protein level （P<0.05）.When feeding with high protein level diet，the ammonia nitrogen excretion rate of mandarin fish in G3 group was noticeably higher than that in G1 group （P<0.05）.The above results showed that dietary protein content had significant effects on the growth performance，digestion and metabolic indexes of mandarin with three sizes，and the optimal protein requirement could be determined to achieve the optimal healthy breeding effect for mandarin fish.
To determine the dietary protein requirement of mandarin fish （Siniperca chuatsi） with different sizes，mandarin fish with initial body weight of （11.58±1.34） g （G1），（94.77±2.59） g （G2） and （245.26±3.59） g （G3） were selected to investigate the effects of different dietary protein levels on growth performance，feed utilization rate，morphological indexes，digestive enzyme activity，antioxidant capacity and ammonia nitrogen excretion.The results showed that when the protein content was 500 g/kg，the specific growth rate （SGR），final body weight （FBW） and weight gain rate （WGR） of mandarin fish in G1 and G2 groups were the highest，while when the protein content was 450 g/kg，those in group G3 were the highest.The feed coefficient showed an opposite trend.Based on the analysis of SGR’s broken-line regression model，the optimal protein requirements of three different sizes of mandarin fish were 497.1 g/kg，451.9 g/kg and 446 g/kg，respectively.The survival rate of mandarin fish with small and middle sizes fed with low protein level （350 g/kg and 400 g/kg） diet was significantly lower than that of other groups （P<0.05），but dietary protein level had no significant effect on survival rate of mandarin fish in G3 group （P>0.05）.Condition factor，hepotasomatic index and viscerasomatic index of mandarin fish in G1 and G2 groups decreased significantly with the increase of dietary protein level （P<0.05）.With the increase of dietary protein level，the dry matter apparent digestibility coefficient （ADC） of mandarin fish was first increased and then stabilized in G1 and G3 groups，while that in G2 group was first increased and then decreased.With the increase of dietary protein level，the crude protein ADC of mandarin fish with three different sizes increased significantly （P<0.05） and decreased slightly after reaching the highest value at 500 g/kg protein level.A similar trend was observed in trypsin activity of the foregut.The activities of glutamic-pyruvic transaminase and glutamic-oxalacetic transaminase in liver of mandarin fish at three different growth stages increased dramatically as dietary protein level elevated （P<0.05）.The ammonia nitrogen excretion rate of mandarin fish with three different sizes reached the peak at 6 h after feeding and increased significantly with the increase of dietary protein level （P<0.05）.When feeding with high protein level diet，the ammonia nitrogen excretion rate of mandarin fish in G3 group was noticeably higher than that in G1 group （P<0.05）.The above results showed that dietary protein content had significant effects on the growth performance，digestion and metabolic indexes of mandarin with three sizes，and the optimal protein requirement could be determined to achieve the optimal healthy breeding effect for mandarin fish.
2023,42(4):225-235
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.026
Abstract:
Neuropeptide Y receptors （YR） are thought to mediate multiple physiological functions of teleost NPY family peptides，such as feeding. However，the structure and signaling of fish NPY receptors have not been fully elucidated. In this study，the gene structure，tissue expression and signaling of YR in grass carp （Ctenopharyngodon idellus） were reported. The sequences of seven YR genes of Y1R，Y2R，Y2-2R，Y4R，Y7R，Y8Ra and Y8Rb were obtained in the grass carp genome. Homology analysis of grass carp YR revealed that the amino acid sequences encoded by seven YR isoforms were highly conserved in teleost fish. The results of tissue expression showed that grass carp YR was mainly expressed in central tissues，but also in peripheral tissues，including eyes，gills and intestines. NPY can activate the expression of Y2R，Y4R and Y8Rb in HEK293t cells. Y2R is coupled to the cAMP/PKA signaling pathway and Y4R is coupled to the MAPK/ERK signaling pathway. Y8Rb can activate both cAMP/PKA and MAPK/ERK signaling pathways. Intracerebroventricular injection of NPY could significantly increase the expression of Y1R，Y2R，Y4R and Y8Rb. This study shows that grass carp Y2R，Y4R and Y8Rb are functional and can transmit signals efficiently，and NPY action is likely mediated by these receptors.
Neuropeptide Y receptors （YR） are thought to mediate multiple physiological functions of teleost NPY family peptides，such as feeding. However，the structure and signaling of fish NPY receptors have not been fully elucidated. In this study，the gene structure，tissue expression and signaling of YR in grass carp （Ctenopharyngodon idellus） were reported. The sequences of seven YR genes of Y1R，Y2R，Y2-2R，Y4R，Y7R，Y8Ra and Y8Rb were obtained in the grass carp genome. Homology analysis of grass carp YR revealed that the amino acid sequences encoded by seven YR isoforms were highly conserved in teleost fish. The results of tissue expression showed that grass carp YR was mainly expressed in central tissues，but also in peripheral tissues，including eyes，gills and intestines. NPY can activate the expression of Y2R，Y4R and Y8Rb in HEK293t cells. Y2R is coupled to the cAMP/PKA signaling pathway and Y4R is coupled to the MAPK/ERK signaling pathway. Y8Rb can activate both cAMP/PKA and MAPK/ERK signaling pathways. Intracerebroventricular injection of NPY could significantly increase the expression of Y1R，Y2R，Y4R and Y8Rb. This study shows that grass carp Y2R，Y4R and Y8Rb are functional and can transmit signals efficiently，and NPY action is likely mediated by these receptors.
2023,42(4):236-243
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.027
Abstract:
To address the issues of low prediction accuracy and slow convergence rate of ammonia nitrogen concentration model under small sample data， a method of establishing ammonia nitrogen concentration prediction model by using long short-term memory （LSTM） and optimizing the model by using Bayesian optimization algorithm and Meta-learning mechanism was proposed. The Bayesian optimization algorithm was used to optimize the superparameters of the prediction model， and the initial values of the model parameters were given. Then the Meta-LSTM algorithm was used to learn the model gradient and allow the parameter sharing and updating among the optimizers， and finally the optimization of the prediction model of ammonia nitrogen concentration was realized. Compared with LSTM， GRU and RNN models， the result shows that the root-mean-square error， mean absolute error and mean square error of the proposed model are 0.027 6， 0.023 9 and 0.000 76， respectively， which are better than other prediction models. It is further indicated that the prediction model of ammonia nitrogen concentration based on Bayesian and Meta-learning is effective for modeling small sample data， and can achieve convergence in rapid training. The accuracy of the model meets the prediction requirements of ammonia nitrogen concentration for aquaculture.
To address the issues of low prediction accuracy and slow convergence rate of ammonia nitrogen concentration model under small sample data， a method of establishing ammonia nitrogen concentration prediction model by using long short-term memory （LSTM） and optimizing the model by using Bayesian optimization algorithm and Meta-learning mechanism was proposed. The Bayesian optimization algorithm was used to optimize the superparameters of the prediction model， and the initial values of the model parameters were given. Then the Meta-LSTM algorithm was used to learn the model gradient and allow the parameter sharing and updating among the optimizers， and finally the optimization of the prediction model of ammonia nitrogen concentration was realized. Compared with LSTM， GRU and RNN models， the result shows that the root-mean-square error， mean absolute error and mean square error of the proposed model are 0.027 6， 0.023 9 and 0.000 76， respectively， which are better than other prediction models. It is further indicated that the prediction model of ammonia nitrogen concentration based on Bayesian and Meta-learning is effective for modeling small sample data， and can achieve convergence in rapid training. The accuracy of the model meets the prediction requirements of ammonia nitrogen concentration for aquaculture.
2023,42(4):244-253
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.028
Abstract:
As a high-value carotenoid， lycopene has many physiological functions， such as anti-oxidation， scavenging free radicals and preventing heart cerebrovascular disease. It is widely used in fields such as food and medicine. At present， lycopene mainly comes from natural tomato extraction， and its market application is limited due to the limited production capacity. While the biotechnology represented by synthetic biology has brought the dawn for the innovative production of lycopene. In this paper， the physicochemical properties， physiological functions and production methods of lycopene were summarized according to the relevant domestic and foreign research literature. In particular this paper focuses on the recent research progress in the metabolic engineering， fermentation and extraction of lycopene by biotechnology. The research status of lycopene synthetic biology was systematically reviewed. Finally， the future direction and problems of lycopene production by biotechnology are prospected， so as to provide reference for the related research on the biosynthesis of lycopene.
As a high-value carotenoid， lycopene has many physiological functions， such as anti-oxidation， scavenging free radicals and preventing heart cerebrovascular disease. It is widely used in fields such as food and medicine. At present， lycopene mainly comes from natural tomato extraction， and its market application is limited due to the limited production capacity. While the biotechnology represented by synthetic biology has brought the dawn for the innovative production of lycopene. In this paper， the physicochemical properties， physiological functions and production methods of lycopene were summarized according to the relevant domestic and foreign research literature. In particular this paper focuses on the recent research progress in the metabolic engineering， fermentation and extraction of lycopene by biotechnology. The research status of lycopene synthetic biology was systematically reviewed. Finally， the future direction and problems of lycopene production by biotechnology are prospected， so as to provide reference for the related research on the biosynthesis of lycopene.
2023,42(4):254-261
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.029
Abstract:
In order to explore the impact of TGase from different species of freshwater fish on gel properties， the effect of silver carp transglutaminase （STG） or black carp transglutaminase （BTG） on the solubility， protein aggregation， rheological properties， puncture properties， and microscopic morphology of myosin after low-temperature gelation were evaluated. Results showed that the addition of STG/BTG promoted formation of more ε-（γ-Glu）-Lys covalent bonds in myosin heavy chain （MHC） of silver carp or black carp compared with the group without enzyme addition， resulting in more aggregation of MHC. The turbidity and average particle size of myosin， the elastic modulus（G'）， breaking force， and breaking distance of myosin gel increased significantly， and the protein network structure was enhanced. In terms of enhancing the gel properties of the same myosin， the catalytic cross-linking effect of BTG was stronger than that of STG， while the activity of BTG （12.67 U/mg） was lower than that of STG （14.34 U/mg）， and the myosin gel properties of black carp were always higher than those of silver carp regardless of TGase addition. In conclusion， the essential reason for the differences in gel properties of surimi from different freshwater fish species was the source of myosin rather than the differences in TGase activity.
In order to explore the impact of TGase from different species of freshwater fish on gel properties， the effect of silver carp transglutaminase （STG） or black carp transglutaminase （BTG） on the solubility， protein aggregation， rheological properties， puncture properties， and microscopic morphology of myosin after low-temperature gelation were evaluated. Results showed that the addition of STG/BTG promoted formation of more ε-（γ-Glu）-Lys covalent bonds in myosin heavy chain （MHC） of silver carp or black carp compared with the group without enzyme addition， resulting in more aggregation of MHC. The turbidity and average particle size of myosin， the elastic modulus（G'）， breaking force， and breaking distance of myosin gel increased significantly， and the protein network structure was enhanced. In terms of enhancing the gel properties of the same myosin， the catalytic cross-linking effect of BTG was stronger than that of STG， while the activity of BTG （12.67 U/mg） was lower than that of STG （14.34 U/mg）， and the myosin gel properties of black carp were always higher than those of silver carp regardless of TGase addition. In conclusion， the essential reason for the differences in gel properties of surimi from different freshwater fish species was the source of myosin rather than the differences in TGase activity.
2023,42(4):262-269
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.030
Abstract:
An improved YOLOv5s-based method for rapidly detecting strawberry ripeness was proposed to solve the problem of rapid and accurate identification of strawberry fruits in greenhouse. The Shuffle_Block was introduced as a feature extraction network in the backbone to lightweight the model.Meanwhile，the omni-dimensional dynamic convolution （ODConv） module was used in the neck structure to enhance the information mining ability of model for strawberry targets，reduce computational complexity，and further achieve lightweight.The results showed that the average precision of the improved YOLO-ODM model reached 97.4%.The model size is 7.79 Mb.The average detection time on the GPU is only 11 ms per image，and the floating-point operations are 6.9×109 FLOPs.Compared with the original network，the lightweighted YOLO-ODM method improved the accuracy of detection while reducing model size by 43% and floating-point operations by 52%.It is indicated that the lightweighted method can rapidly and accurately detect the ripeness of strawberry fruit in greenhouse，monitor the growth status of strawberries.
An improved YOLOv5s-based method for rapidly detecting strawberry ripeness was proposed to solve the problem of rapid and accurate identification of strawberry fruits in greenhouse. The Shuffle_Block was introduced as a feature extraction network in the backbone to lightweight the model.Meanwhile，the omni-dimensional dynamic convolution （ODConv） module was used in the neck structure to enhance the information mining ability of model for strawberry targets，reduce computational complexity，and further achieve lightweight.The results showed that the average precision of the improved YOLO-ODM model reached 97.4%.The model size is 7.79 Mb.The average detection time on the GPU is only 11 ms per image，and the floating-point operations are 6.9×109 FLOPs.Compared with the original network，the lightweighted YOLO-ODM method improved the accuracy of detection while reducing model size by 43% and floating-point operations by 52%.It is indicated that the lightweighted method can rapidly and accurately detect the ripeness of strawberry fruit in greenhouse，monitor the growth status of strawberries.
2023,42(4):270-278
, DOI: 10.13300/j.cnki.hnlkxb.2023.04.031
Abstract:
To address the problem of the lack of effective discrete element models in the design and simulation analysis of water caltrop dehulling primary processing equipment， this paper carries out the research work of water caltrop discrete element parameter calibration and prototype test. The 3D inverse technique was used to obtain the water caltrop profile model， and the water caltrop intrinsic parameters and basic contact parameters were measured by physical tests. The average shearing force of the water caltrop was obtained from the uniaxial compression test as 352.95 N， and this was used as the calibration target. Based on the Hertz-Mindlin with bonding model， a water caltrop discrete element model was established to carry out virtual calibration tests on bonding parameters， and the calibration range of each parameter was initially screened by single-factor tests. The two-level analysis factor test and the steepest climb test were used to quickly screen the significant factors and their calibration intervals， and the Central composite response surface test was designed to solve the bonding parameters to determine the optimal combination of parameters in the discrete element model， and a rotary shear water caltrop simulation model was established to study the effects of different tools on water caltrop shear at different rotational speeds， which was used as a basis to design a shear vibration-type water caltrop sheller to carry out prototype tests to verify the reliability of the model. The results show that，the significant effect on the shearing force of the factor normal stiffness per unit area is 4.818×107 N/m3， shear stiffness per unit area is 5.343×108 N/m3， the remaining insignificant factors are taken as the middle level， that is， the normal stress per unit area is 1×107 Pa， shear stress per unit area is 1×107 Pa， bond radius of 1.6 mm. The shearing force of the simulated test is 352 N， with an error of 0.269%； the minimum shearing force of the rectangular tool screened from the rotary shear test is 93.20 N at 230 r/min， with an error of 0.215% from the predicted value of 92.99 N； the prototype test shows that the rectangular tool has better performance than other rotational speeds in shearing water caltrop angles at 230 r/min； the comprehensive demonstration shows that the established discrete element model of water caltrop can provide a reference basis for the design of dehulling tools and the determination of key parameters for water caltrop primary machining equipment.
To address the problem of the lack of effective discrete element models in the design and simulation analysis of water caltrop dehulling primary processing equipment， this paper carries out the research work of water caltrop discrete element parameter calibration and prototype test. The 3D inverse technique was used to obtain the water caltrop profile model， and the water caltrop intrinsic parameters and basic contact parameters were measured by physical tests. The average shearing force of the water caltrop was obtained from the uniaxial compression test as 352.95 N， and this was used as the calibration target. Based on the Hertz-Mindlin with bonding model， a water caltrop discrete element model was established to carry out virtual calibration tests on bonding parameters， and the calibration range of each parameter was initially screened by single-factor tests. The two-level analysis factor test and the steepest climb test were used to quickly screen the significant factors and their calibration intervals， and the Central composite response surface test was designed to solve the bonding parameters to determine the optimal combination of parameters in the discrete element model， and a rotary shear water caltrop simulation model was established to study the effects of different tools on water caltrop shear at different rotational speeds， which was used as a basis to design a shear vibration-type water caltrop sheller to carry out prototype tests to verify the reliability of the model. The results show that，the significant effect on the shearing force of the factor normal stiffness per unit area is 4.818×107 N/m3， shear stiffness per unit area is 5.343×108 N/m3， the remaining insignificant factors are taken as the middle level， that is， the normal stress per unit area is 1×107 Pa， shear stress per unit area is 1×107 Pa， bond radius of 1.6 mm. The shearing force of the simulated test is 352 N， with an error of 0.269%； the minimum shearing force of the rectangular tool screened from the rotary shear test is 93.20 N at 230 r/min， with an error of 0.215% from the predicted value of 92.99 N； the prototype test shows that the rectangular tool has better performance than other rotational speeds in shearing water caltrop angles at 230 r/min； the comprehensive demonstration shows that the established discrete element model of water caltrop can provide a reference basis for the design of dehulling tools and the determination of key parameters for water caltrop primary machining equipment.
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Abstract:
Abstract: The differences of fruit quality between protected cultivation and open cultivation (CK) mode were studied with Cocktail grapefruit as material. The results showed that the single fruit weight, transverse and longitudinal diameter and fruit shape index of protected cultivation were larger than those in the open air, and there was no significant difference in peel hardness during fruit development, but there was a significant difference in peel hardness from 227d days after anthesis. Protected cultivation significantly increased the soluble solid content of fruit to 10.43%, the titratable acid and Vc contents were higher than those in the open air. Through GC-MS, it was found that protected cultivation could increase the sucrose content of fruit to 49.63mg/g. Real-time quantitative PCR analysis showed that protected cultivation might increase the sucrose content in fruit by up-regulating the expression levels of CsSPS2, CsSUS2 and CsSUS4. Facility cultivation can improve the fruit quality of chicken-tailed grapefruit.
Abstract: The differences of fruit quality between protected cultivation and open cultivation (CK) mode were studied with Cocktail grapefruit as material. The results showed that the single fruit weight, transverse and longitudinal diameter and fruit shape index of protected cultivation were larger than those in the open air, and there was no significant difference in peel hardness during fruit development, but there was a significant difference in peel hardness from 227d days after anthesis. Protected cultivation significantly increased the soluble solid content of fruit to 10.43%, the titratable acid and Vc contents were higher than those in the open air. Through GC-MS, it was found that protected cultivation could increase the sucrose content of fruit to 49.63mg/g. Real-time quantitative PCR analysis showed that protected cultivation might increase the sucrose content in fruit by up-regulating the expression levels of CsSPS2, CsSUS2 and CsSUS4. Facility cultivation can improve the fruit quality of chicken-tailed grapefruit.
Abstract:
As an important part of urban public space, community public sports service space is the primary place for people to keep fit. High quality public sports space can effectively improve people's quality of life. At present, the public sports service space in China is still in the stage of "reconstruction, establishment and neglect of management". The lack of consideration on the use of venues and residents' satisfaction in planning and construction has led to unscientific allocation of public sports service space, low utilization efficiency and low service level, which has affected the development of national fitness. In addition, with the increasing number of residents in the old city and the aging of public sports service facilities, the original public sports service space in the old city has been unable to effectively meet the people's high-quality fitness needs. Therefore, it is particularly important to optimize the layout of new and reconstructed public sports service facilities. This paper takes Jinniu District of Chengdu City as the research object to conduct empirical research, collect POI for data collection, analyze the accessibility of large public sports facilities based on ArcGIS road network analysis method, and analyze the balance degree of public sports service spatial layout by applying Gini coefficient and Lorenz curve. The results show that there are some problems in Jinniu District, such as insufficient scale of public sports service space, low accessibility from residential areas to public sports facilities, and mismatch between population distribution and public sports space layout. We should increase the supply of public sports facilities, improve the transportation conditions from public sports facilities to residential areas, and improve the coverage of public sports space in populous streets, so as to improve the fitness difficulties and poor fitness experience in old communities, and promote the high-quality development of national fitness.
As an important part of urban public space, community public sports service space is the primary place for people to keep fit. High quality public sports space can effectively improve people's quality of life. At present, the public sports service space in China is still in the stage of "reconstruction, establishment and neglect of management". The lack of consideration on the use of venues and residents' satisfaction in planning and construction has led to unscientific allocation of public sports service space, low utilization efficiency and low service level, which has affected the development of national fitness. In addition, with the increasing number of residents in the old city and the aging of public sports service facilities, the original public sports service space in the old city has been unable to effectively meet the people's high-quality fitness needs. Therefore, it is particularly important to optimize the layout of new and reconstructed public sports service facilities. This paper takes Jinniu District of Chengdu City as the research object to conduct empirical research, collect POI for data collection, analyze the accessibility of large public sports facilities based on ArcGIS road network analysis method, and analyze the balance degree of public sports service spatial layout by applying Gini coefficient and Lorenz curve. The results show that there are some problems in Jinniu District, such as insufficient scale of public sports service space, low accessibility from residential areas to public sports facilities, and mismatch between population distribution and public sports space layout. We should increase the supply of public sports facilities, improve the transportation conditions from public sports facilities to residential areas, and improve the coverage of public sports space in populous streets, so as to improve the fitness difficulties and poor fitness experience in old communities, and promote the high-quality development of national fitness.
Abstract:
Lily (Lilium spp.) is one of the most important cut flowers, which occupies an important position in the cut flower consumption market around the world. However, lily cut flowers can’t be stored or transported for a long period. Huge postharvest loss and short vase life, severely restrict its industrial development. In order to understand the molecular mechanism underlying the flower senescence of lilies, a senescence-associated gene named SAG10 was selected. The expression of SAG10 is not only extremely high during flowers and leafs senescence in lilies, but also induced by abscisic acid (ABA) and salicylic acid (SA). Through alignment of protein sequences, SAG10 was officially named as LoENDONUCLEASE 1 (accession NO. OP589201). The full length of LoENDONUCLEASE 1 was successfully transferred into Arabidopsis thaliana with the mediation of Agrobacterium tumfaciens GV3101. In addition, LoENDONUCLEASE 1 was transiently overexpressed in the tepals of lily ‘Siberia’. The results showed that LoENDONUCLEASE 1 significantly promoted the senescence both in leaves of Arabidopsis thaliana and tepals of Lilium oriental hybrid ‘Siberia’.
Lily (Lilium spp.) is one of the most important cut flowers, which occupies an important position in the cut flower consumption market around the world. However, lily cut flowers can’t be stored or transported for a long period. Huge postharvest loss and short vase life, severely restrict its industrial development. In order to understand the molecular mechanism underlying the flower senescence of lilies, a senescence-associated gene named SAG10 was selected. The expression of SAG10 is not only extremely high during flowers and leafs senescence in lilies, but also induced by abscisic acid (ABA) and salicylic acid (SA). Through alignment of protein sequences, SAG10 was officially named as LoENDONUCLEASE 1 (accession NO. OP589201). The full length of LoENDONUCLEASE 1 was successfully transferred into Arabidopsis thaliana with the mediation of Agrobacterium tumfaciens GV3101. In addition, LoENDONUCLEASE 1 was transiently overexpressed in the tepals of lily ‘Siberia’. The results showed that LoENDONUCLEASE 1 significantly promoted the senescence both in leaves of Arabidopsis thaliana and tepals of Lilium oriental hybrid ‘Siberia’.
Abstract:
Aiming at the current problems of low efficiency and low accuracy of automatic cow lameness detection in farms, this study designs a cow lameness recognition method based on posture estimation and knee angle eigenvectors. Given that the behavior of cows is characterized by random stays, a cow posture estimation dataset is produced by combining the imaging characteristics of cows under different conditions such as near and far field of view scales and observation angles. The Faster RCNN convolutional neural network model is introduced into the cow key point detection to improve the reliability of lameness recognition; the ResNet101 network is used as the feature extraction network, the cow posture estimation network is constructed, and the hyperparameter fine-tuning training method is used to migrate the network model for training. Through the cow posture information and key point coordinate information in the video, the angle characteristics of the knee joint of the cow when walking were calculated, and the 1-D Convolution classification model was used to realize the cow's lameness recognition. The experimental results show that the PCK0.1 value of the cow posture estimation network based on the ResNet101 network model can reach 0.9250; the accuracy of the cow behavior classification and recognition using the 1-D Convolution model is 97.22%, which is 5.55%, 2.78%, respectively, compared with the LSTM, Bi-LSTM, and GRU models, 11.11%. The above results show that the proposed method has better detection effect on cow lameness in natural environment, which can provide technical reference for intelligent dairy cattle breeding and management.
Aiming at the current problems of low efficiency and low accuracy of automatic cow lameness detection in farms, this study designs a cow lameness recognition method based on posture estimation and knee angle eigenvectors. Given that the behavior of cows is characterized by random stays, a cow posture estimation dataset is produced by combining the imaging characteristics of cows under different conditions such as near and far field of view scales and observation angles. The Faster RCNN convolutional neural network model is introduced into the cow key point detection to improve the reliability of lameness recognition; the ResNet101 network is used as the feature extraction network, the cow posture estimation network is constructed, and the hyperparameter fine-tuning training method is used to migrate the network model for training. Through the cow posture information and key point coordinate information in the video, the angle characteristics of the knee joint of the cow when walking were calculated, and the 1-D Convolution classification model was used to realize the cow's lameness recognition. The experimental results show that the PCK0.1 value of the cow posture estimation network based on the ResNet101 network model can reach 0.9250; the accuracy of the cow behavior classification and recognition using the 1-D Convolution model is 97.22%, which is 5.55%, 2.78%, respectively, compared with the LSTM, Bi-LSTM, and GRU models, 11.11%. The above results show that the proposed method has better detection effect on cow lameness in natural environment, which can provide technical reference for intelligent dairy cattle breeding and management.
Abstract:
Ecological space is an important vehicle for maintaining regional carbon balance and securing carbon storage, and the ecological protection red line area is an important part of ecological space. This study aims to investigate the spatial and temporal response of the carbon storage function of the ecological space under the ecological bottom line constraint and use the ArcGIS platform to integrate the PLUS model and the InVEST-Carbon model to predict and simulate the change of ecological space carbon storage and its spatial characteristics in Xiangyang from 2000 to 2030. The results show that: 1) Between 2000 and 2020, the area of ecological space in Xiangyang City has reduced. It is predicted that under the constraint of the ecological baseline, the rate of ecological space degradation will decrease by 2030;2) By 2030, the carbon storage of Xiangyang City will change accordingly due to the change in ecological space. The maximum carbon storage per grid unit is about 18.47 kg, mainly distributed in the forest areas in the west, northeast, and southeast; 3) The hotspot analysis presents a pattern of "concentrated hotspots, dispersed cold spots". The constraint of the ecological baseline helps optimize the carbon hotspot pattern of Xiangyang City's ecological space. These findings can provide scientific guidance for implementing "carbon peaking and carbon neutrality" strategies and promoting low-carbon planning in similar regions. This paper also highlights the crucial role of ecological space planning and policies such as Ecological Redline in mitigating the effects of climate change by regulating LULC and preserving carbon storage.
Ecological space is an important vehicle for maintaining regional carbon balance and securing carbon storage, and the ecological protection red line area is an important part of ecological space. This study aims to investigate the spatial and temporal response of the carbon storage function of the ecological space under the ecological bottom line constraint and use the ArcGIS platform to integrate the PLUS model and the InVEST-Carbon model to predict and simulate the change of ecological space carbon storage and its spatial characteristics in Xiangyang from 2000 to 2030. The results show that: 1) Between 2000 and 2020, the area of ecological space in Xiangyang City has reduced. It is predicted that under the constraint of the ecological baseline, the rate of ecological space degradation will decrease by 2030;2) By 2030, the carbon storage of Xiangyang City will change accordingly due to the change in ecological space. The maximum carbon storage per grid unit is about 18.47 kg, mainly distributed in the forest areas in the west, northeast, and southeast; 3) The hotspot analysis presents a pattern of "concentrated hotspots, dispersed cold spots". The constraint of the ecological baseline helps optimize the carbon hotspot pattern of Xiangyang City's ecological space. These findings can provide scientific guidance for implementing "carbon peaking and carbon neutrality" strategies and promoting low-carbon planning in similar regions. This paper also highlights the crucial role of ecological space planning and policies such as Ecological Redline in mitigating the effects of climate change by regulating LULC and preserving carbon storage.
Abstract:
Olfaction is an important sensory systems in fish due to its role in many behavioral activities. Olfactory receptors, as one of the largest gene families in vertebrates, could detect and discriminate tens of thousands of odorants. They are critical to food selection and toxic identification. To explore the potential role of olfactory receptors β subtype (OR-β) in the evolution of feeding adaptation in fish, we analyzed OR-β from 12 fish species with different feeding habits including Megalobrama amblycephala, Ctenopharyngodon idellus, Cynoglossus semilaevis, Gadus morhua, Gasterosteus aculeatus, Larimichthys crocea, Paralichthys olivaceus, Danio rerio, Oreochromis niloticus, Oryzias latipes, Sinocyclocheilus graham and Xiphophorus maculatus. We also detected the expression patterns of the OR-β in muscle, olfactory epithelium, olfactory bulb and brain of M. amblycephala. The results showed that the number of OR-β varied greatly among different feeding fish species, with 20 copies in M. amblycephala and 14 copies in C. idellus, respectively. However, carnivorous and omnivorous fish have an average of 1 and 4 copies, respectively. During the evolutionary process, the OR-β gene of fish diverged. OR-β of several Cyprinidae fish clustered together and were strongly positive selected. The results of qRT-PCR showed that 10 OR-β genes were highly expressed in the olfactory epithelium of M. amblycephala at 1-year-old and 2-year-old M. amblycephala. OR-β-9 and OR-β-10 were also expressed in the olfactory bulb and brain tissue, while other OR-β genes were not expressed. Taken together, these results showed that OR-β genes in the two herbivorous fish were the specific expanded and highly expressed in the olfactory epithelium, suggesting that OR-β might play potential crucial role in the adaptation to their herbivore diet.
Olfaction is an important sensory systems in fish due to its role in many behavioral activities. Olfactory receptors, as one of the largest gene families in vertebrates, could detect and discriminate tens of thousands of odorants. They are critical to food selection and toxic identification. To explore the potential role of olfactory receptors β subtype (OR-β) in the evolution of feeding adaptation in fish, we analyzed OR-β from 12 fish species with different feeding habits including Megalobrama amblycephala, Ctenopharyngodon idellus, Cynoglossus semilaevis, Gadus morhua, Gasterosteus aculeatus, Larimichthys crocea, Paralichthys olivaceus, Danio rerio, Oreochromis niloticus, Oryzias latipes, Sinocyclocheilus graham and Xiphophorus maculatus. We also detected the expression patterns of the OR-β in muscle, olfactory epithelium, olfactory bulb and brain of M. amblycephala. The results showed that the number of OR-β varied greatly among different feeding fish species, with 20 copies in M. amblycephala and 14 copies in C. idellus, respectively. However, carnivorous and omnivorous fish have an average of 1 and 4 copies, respectively. During the evolutionary process, the OR-β gene of fish diverged. OR-β of several Cyprinidae fish clustered together and were strongly positive selected. The results of qRT-PCR showed that 10 OR-β genes were highly expressed in the olfactory epithelium of M. amblycephala at 1-year-old and 2-year-old M. amblycephala. OR-β-9 and OR-β-10 were also expressed in the olfactory bulb and brain tissue, while other OR-β genes were not expressed. Taken together, these results showed that OR-β genes in the two herbivorous fish were the specific expanded and highly expressed in the olfactory epithelium, suggesting that OR-β might play potential crucial role in the adaptation to their herbivore diet.
Abstract:
To understand the current status of fish resources in Lake Bosten and their relationship with environmental factors, a lake-wide acoustic survey was conducted in May (spring), July-August (summer), and October (autumn) of 2019 using a split-beam echosounder (Simrad EY60, 120 kHz), along with on-site measurements of water environmental indicators. The results showed that fish density in Lake Bosten was highest in summer, with an average value of 8783 ± 2611 ind./hm2. There was no significant difference between spring and autumn, with average values of 709 ± 141 ind./hm2 and 743 ± 499 ind./hm2, respectively. Based on the empirical formula relating target strength to fish size, the average total length of fish in spring, summer, and autumn were estimated to be 8.8 cm, 4.0 cm, and 5.1 cm, respectively. Correlation analysis indicated that fish density in Lake Bosten was significantly positively correlated with chlorophyll-a, water temperature, conductivity, and dissolved oxygen (P < 0.05), while it was significantly negatively correlated with water depth, transparency, and pH (P < 0.05). The feature importance ranking of the random forest model revealed that conductivity was the most important factor influencing fish density in Lake Bosten, followed by dissolved oxygen, salinity, and water temperature. The seasonal variation in fish density is presumed to be closely related to environmental changes, food sources, and reproductive habits. Environmental factors may affect fish ecological requirements directly or indirectly. This study contributes to the improvement of basic information on fish resources in Lake Bosten and highlights the need to consider not only the fish themselves but also the changes in their living environment for fish conservation.
To understand the current status of fish resources in Lake Bosten and their relationship with environmental factors, a lake-wide acoustic survey was conducted in May (spring), July-August (summer), and October (autumn) of 2019 using a split-beam echosounder (Simrad EY60, 120 kHz), along with on-site measurements of water environmental indicators. The results showed that fish density in Lake Bosten was highest in summer, with an average value of 8783 ± 2611 ind./hm2. There was no significant difference between spring and autumn, with average values of 709 ± 141 ind./hm2 and 743 ± 499 ind./hm2, respectively. Based on the empirical formula relating target strength to fish size, the average total length of fish in spring, summer, and autumn were estimated to be 8.8 cm, 4.0 cm, and 5.1 cm, respectively. Correlation analysis indicated that fish density in Lake Bosten was significantly positively correlated with chlorophyll-a, water temperature, conductivity, and dissolved oxygen (P < 0.05), while it was significantly negatively correlated with water depth, transparency, and pH (P < 0.05). The feature importance ranking of the random forest model revealed that conductivity was the most important factor influencing fish density in Lake Bosten, followed by dissolved oxygen, salinity, and water temperature. The seasonal variation in fish density is presumed to be closely related to environmental changes, food sources, and reproductive habits. Environmental factors may affect fish ecological requirements directly or indirectly. This study contributes to the improvement of basic information on fish resources in Lake Bosten and highlights the need to consider not only the fish themselves but also the changes in their living environment for fish conservation.
Abstract:
Grassland animal husbandry is an important part of modern animal husbandry, as well as a traditional, basic, characteristic, and advantageous industry in Xinjiang. The high-quality development of grassland animal husbandry requires taking into account the high quality of products, grassland restoration, herdsmen 's income increase and cultural inheritance. There is still a large space for transformation and upgrading of grassland animal husbandry in Xinjiang on the basis of the development status. At present, the realistic dilemma faced by Xinjiang in the process of transformation and upgrading of grassland animal husbandry include the transformation of breeding mode and the lack of technology application affecting the quality of animal products, overgrazing on natural grasslands affecting ecological restoration, insufficient development of the industry chain affecting the increase in income of herdsmen and the transformation of herdsmen 's production and lifestyle affecting the inheritance of grassland culture. The research holds that the essence of the high-quality development of grassland animal husbandry is the dynamic balance of ' grass-animal-human-culture '. In the transformation and upgrading of grassland animal husbandry in Xinjiang, Xinjiang should pay attention to the matching of scientific and technological research and development application and breeding mode, improve incentive policies and grazing management measures, accelerate the construction and value-added of the whole industry chain, and strengthen the cultural characteristics of grassland animal husbandry in Xinjiang.
Grassland animal husbandry is an important part of modern animal husbandry, as well as a traditional, basic, characteristic, and advantageous industry in Xinjiang. The high-quality development of grassland animal husbandry requires taking into account the high quality of products, grassland restoration, herdsmen 's income increase and cultural inheritance. There is still a large space for transformation and upgrading of grassland animal husbandry in Xinjiang on the basis of the development status. At present, the realistic dilemma faced by Xinjiang in the process of transformation and upgrading of grassland animal husbandry include the transformation of breeding mode and the lack of technology application affecting the quality of animal products, overgrazing on natural grasslands affecting ecological restoration, insufficient development of the industry chain affecting the increase in income of herdsmen and the transformation of herdsmen 's production and lifestyle affecting the inheritance of grassland culture. The research holds that the essence of the high-quality development of grassland animal husbandry is the dynamic balance of ' grass-animal-human-culture '. In the transformation and upgrading of grassland animal husbandry in Xinjiang, Xinjiang should pay attention to the matching of scientific and technological research and development application and breeding mode, improve incentive policies and grazing management measures, accelerate the construction and value-added of the whole industry chain, and strengthen the cultural characteristics of grassland animal husbandry in Xinjiang.
Abstract:
Aquaculture of captive-pond mode has higher sewage efficiency and higher breeding density, due to the benefit upon frequent removals of aquaculture waste in the captive tank. However, dissolved oxygen in the water of densified aquaculture is a concern of farmers. When the water temperature is high in summer, air aeration is inefficient, and bubble-based aeration method cannot meet the requirements of supplying oxygen. Gas-liquid mixed pump has a great performance on dissolved oxygen in sewage aeration treatment. To explore whether it is suitable for pond-captive mode’s oxygenation, experimental test is needed to explore the optimal process parameters. In this study, performances of the pump were tested under different water temperatures, outlet pressures and gas-water volume ratios, and tests were carried out on site in the pond captive tank (diameter 4 m, height 2 m, aquaculture water volume 20 m^3). The test results of dissolved oxygen performance showed that, under the outlet pressure of 0.25 MPa and the volume ratio of gas to water being 0.01 to 0.05, the dissolved oxygen in the outlet water was inversely proportional to the water temperature at different water temperatures (5.6 ℃, 13.5 ℃ and 30.3 ℃), and the dissolved oxygen varied from 47.93 mg/L to 20.60 mg/L. The oxygen absorption efficiency was inversely proportional to the gas-liquid volume ratio, and the oxygen absorption efficiency varied from 91% to 33.7%. The dynamic efficiency was proportional to volumetric gas-to-liquid ratio, which varied from 22.32 kg O_2/(kW?h)to 55.12 kg O_2/(kW?h). The onsite test showed that, under the condition of oxygen consumption by fish, of which the density was about 13.19 to16.49kg/m^3 , the dissolved oxygen in each captive tank can reach 11 mg/L in the daytime and keep above 8 mg/L at night when the pump’s working power was about 3 kW. The fluctuation of dissolved oxygen in the captive tank was within 0.2 mg/L, and the uniformity was good. The pump system has a simple structure and can work efficiently under high water temperatures.
Aquaculture of captive-pond mode has higher sewage efficiency and higher breeding density, due to the benefit upon frequent removals of aquaculture waste in the captive tank. However, dissolved oxygen in the water of densified aquaculture is a concern of farmers. When the water temperature is high in summer, air aeration is inefficient, and bubble-based aeration method cannot meet the requirements of supplying oxygen. Gas-liquid mixed pump has a great performance on dissolved oxygen in sewage aeration treatment. To explore whether it is suitable for pond-captive mode’s oxygenation, experimental test is needed to explore the optimal process parameters. In this study, performances of the pump were tested under different water temperatures, outlet pressures and gas-water volume ratios, and tests were carried out on site in the pond captive tank (diameter 4 m, height 2 m, aquaculture water volume 20 m^3). The test results of dissolved oxygen performance showed that, under the outlet pressure of 0.25 MPa and the volume ratio of gas to water being 0.01 to 0.05, the dissolved oxygen in the outlet water was inversely proportional to the water temperature at different water temperatures (5.6 ℃, 13.5 ℃ and 30.3 ℃), and the dissolved oxygen varied from 47.93 mg/L to 20.60 mg/L. The oxygen absorption efficiency was inversely proportional to the gas-liquid volume ratio, and the oxygen absorption efficiency varied from 91% to 33.7%. The dynamic efficiency was proportional to volumetric gas-to-liquid ratio, which varied from 22.32 kg O_2/(kW?h)to 55.12 kg O_2/(kW?h). The onsite test showed that, under the condition of oxygen consumption by fish, of which the density was about 13.19 to16.49kg/m^3 , the dissolved oxygen in each captive tank can reach 11 mg/L in the daytime and keep above 8 mg/L at night when the pump’s working power was about 3 kW. The fluctuation of dissolved oxygen in the captive tank was within 0.2 mg/L, and the uniformity was good. The pump system has a simple structure and can work efficiently under high water temperatures.
Abstract:
The purpose of this study was to investigate the effects of replacing fish meal with soybean meal and adding Clostridium butyricumon on growth performance, feed utilization, body composition and antioxidant performance of largemouth bass. Juvenile largemouth bass (initial body weight 50.78±1.15g) were used as the research object. Seven diets were designed. The fish meal content of control group was 30%, and soybean meal was used to replace fish meal with 25%, 50% and 75%, respectively.?Three groups of soybean meal were supplemented with 0.05% Clostridium butyricum.?An 8-week feeding experiment was conducted, and the growth performance, feed utilization, body composition and antioxidant performance of largemouth bass were analyzed after the feeding experiment.??The results showed that there were no significant differences in growth performance, body composition and antioxidant capacity of largemouth bass when 25% fish meal was replaced by soybean meal (P>0.05). But WGR and SGR of largemouth bass were significantly decreased (P<0.05), and FCR was also significantly increased when the replacement ratio reached 50% (P<0.05), meanwhile?ROS, T-AOC and SOD in liver and serum were significantly changed (P<0.05).??However, there were no significant differences in WGR, SGR, ROS, T-AOC and SOD in the group supplemented with Clostridium butyricum on the basis of replacing 50% fish meal compared with the control group.?When the replacement level reached 75%, the growth performance and antioxidant performance were improved by adding Clostridium butyricum, but still significantly lower than the control group.?The results demonstrated that the addition of 0.05% Clostridium butyricum could improve the negative effects of the proportion of soybean meal replacing fish meal by 50% on the growth performance and antioxidant capacity of largemouth bass.
The purpose of this study was to investigate the effects of replacing fish meal with soybean meal and adding Clostridium butyricumon on growth performance, feed utilization, body composition and antioxidant performance of largemouth bass. Juvenile largemouth bass (initial body weight 50.78±1.15g) were used as the research object. Seven diets were designed. The fish meal content of control group was 30%, and soybean meal was used to replace fish meal with 25%, 50% and 75%, respectively.?Three groups of soybean meal were supplemented with 0.05% Clostridium butyricum.?An 8-week feeding experiment was conducted, and the growth performance, feed utilization, body composition and antioxidant performance of largemouth bass were analyzed after the feeding experiment.??The results showed that there were no significant differences in growth performance, body composition and antioxidant capacity of largemouth bass when 25% fish meal was replaced by soybean meal (P>0.05). But WGR and SGR of largemouth bass were significantly decreased (P<0.05), and FCR was also significantly increased when the replacement ratio reached 50% (P<0.05), meanwhile?ROS, T-AOC and SOD in liver and serum were significantly changed (P<0.05).??However, there were no significant differences in WGR, SGR, ROS, T-AOC and SOD in the group supplemented with Clostridium butyricum on the basis of replacing 50% fish meal compared with the control group.?When the replacement level reached 75%, the growth performance and antioxidant performance were improved by adding Clostridium butyricum, but still significantly lower than the control group.?The results demonstrated that the addition of 0.05% Clostridium butyricum could improve the negative effects of the proportion of soybean meal replacing fish meal by 50% on the growth performance and antioxidant capacity of largemouth bass.
Abstract:
In order to understand the aquatic organism resources and characteristcs of aquatic ecological environment after ecological water transport in lower reaches of Tarim River basin, this study investigated the community structure of macroinvertebrates in the middle and lower reaches of Tarim River, Qarqan River and Taitema Lake, and evaluated their environmental influencing factors during 2019 and 2020. The survey results show that a total of 97 taxa of macroinvertebrates taxa, belonging to 3 phyla, 4 classes, 10 orders and 27 families, were identified during the study. Aquatic insects were the main groups (82 species), among which Diptera (47 species), Coleoptera (14 species) and Odonata (13 species) were the most numerous taxa. Chironomidae were dominant taxa in different regions. The average density and biomass of benthic animals peaked in May, which was more higher than that in August and October, but the diversity indices had no significant difference in time and space (P > 0.05). The main functional feeding groups in the Tarim River and Qarqan River were collector gatherers (95.89%, 91.86%), while the main functional feeding groups in Taitma Lake were collector gatherers (50.68%) and predators (34.12%). The correlation analysis showed that ammonia nitrogen, dissolved oxygen and potassium permanganate were the main environmental factors affecting the diversity and functional groups of benthic animals. The results show that the composition of the macroinvertebrates community in the Tarim River Basin is relatively simple and the ecological environment is relatively fragile. Therefore, it is necessary to continue and deepen the ecological restoration and management of the rivers in this area.
In order to understand the aquatic organism resources and characteristcs of aquatic ecological environment after ecological water transport in lower reaches of Tarim River basin, this study investigated the community structure of macroinvertebrates in the middle and lower reaches of Tarim River, Qarqan River and Taitema Lake, and evaluated their environmental influencing factors during 2019 and 2020. The survey results show that a total of 97 taxa of macroinvertebrates taxa, belonging to 3 phyla, 4 classes, 10 orders and 27 families, were identified during the study. Aquatic insects were the main groups (82 species), among which Diptera (47 species), Coleoptera (14 species) and Odonata (13 species) were the most numerous taxa. Chironomidae were dominant taxa in different regions. The average density and biomass of benthic animals peaked in May, which was more higher than that in August and October, but the diversity indices had no significant difference in time and space (P > 0.05). The main functional feeding groups in the Tarim River and Qarqan River were collector gatherers (95.89%, 91.86%), while the main functional feeding groups in Taitma Lake were collector gatherers (50.68%) and predators (34.12%). The correlation analysis showed that ammonia nitrogen, dissolved oxygen and potassium permanganate were the main environmental factors affecting the diversity and functional groups of benthic animals. The results show that the composition of the macroinvertebrates community in the Tarim River Basin is relatively simple and the ecological environment is relatively fragile. Therefore, it is necessary to continue and deepen the ecological restoration and management of the rivers in this area.
Abstract:
In order to improve the yield of bio-oil production and enhance the quality of bio-oil obtained from black soldier fly larvae, as well as achieve high-value utilization of the larvae, this study employed the method of methanol-water co-solvent liquefaction of black soldier fly larvae to prepare bio-oil. The study investigated the effects of iron-based catalysts (FeS, FeSO4), molecular sieve catalysts (ZSM-5, Y-type molecular sieve), bimetallic catalysts (Ni/TiO2), and molecular sieve-supported metal catalysts (Ni/Y-type molecular sieve) on the distribution and properties of hydrothermal liquefaction products.The results showed that FeSO4 catalyst obtained the highest bio-oil yield, conversion rate, energy recovery rate, and carbon recovery rate in the co-solvent of methanol-water ratio of 4:1. The bio-oil yield reached up to 82.17%, which was 13.94% higher than the bio-oil yield without a catalyst (68.23%). The addition of FeSO4 catalyst effectively suppressed the production of solid products, and the conversion rate reached 91.1%. The improvement of bio-oil yield and conversion rate by iron-based catalysts was attributed to the ability of iron elements to promote the in-situ hydrogenation of liquefaction solvents. In-situ hydrogenation can stabilize the reaction intermediates generated by depolymerization reactions of biomass materials during liquefaction, thereby inhibiting repolymerization reactions. The study found that the esterification reaction between methanol and fatty acids dominated the liquefaction process, and the main compound in the bio-oil was fatty acid methyl ester. Among the catalysts, Ni, as a transition metal, has good redox properties and catalytic activity, can enhance the esterification reaction during the liquefaction reaction process, and inhibit the formation of amide substances during protein hydrolysis.
In order to improve the yield of bio-oil production and enhance the quality of bio-oil obtained from black soldier fly larvae, as well as achieve high-value utilization of the larvae, this study employed the method of methanol-water co-solvent liquefaction of black soldier fly larvae to prepare bio-oil. The study investigated the effects of iron-based catalysts (FeS, FeSO4), molecular sieve catalysts (ZSM-5, Y-type molecular sieve), bimetallic catalysts (Ni/TiO2), and molecular sieve-supported metal catalysts (Ni/Y-type molecular sieve) on the distribution and properties of hydrothermal liquefaction products.The results showed that FeSO4 catalyst obtained the highest bio-oil yield, conversion rate, energy recovery rate, and carbon recovery rate in the co-solvent of methanol-water ratio of 4:1. The bio-oil yield reached up to 82.17%, which was 13.94% higher than the bio-oil yield without a catalyst (68.23%). The addition of FeSO4 catalyst effectively suppressed the production of solid products, and the conversion rate reached 91.1%. The improvement of bio-oil yield and conversion rate by iron-based catalysts was attributed to the ability of iron elements to promote the in-situ hydrogenation of liquefaction solvents. In-situ hydrogenation can stabilize the reaction intermediates generated by depolymerization reactions of biomass materials during liquefaction, thereby inhibiting repolymerization reactions. The study found that the esterification reaction between methanol and fatty acids dominated the liquefaction process, and the main compound in the bio-oil was fatty acid methyl ester. Among the catalysts, Ni, as a transition metal, has good redox properties and catalytic activity, can enhance the esterification reaction during the liquefaction reaction process, and inhibit the formation of amide substances during protein hydrolysis.
Abstract:
s: RACE was used to clone the selenow2a, selenop2 and selenot2 genes with full length cDNAs of 891, 1998 and 1432 bp, respectively, of which the ORFs were 288, 828 and 600 bp in length, encoding 95, 275 and 219 amino acids, respectively. The stop codon encoding selenocysteine was found in the cDNA sequence, and the selenocysteine insertion sequence (SECIS) element was found in the 3′ untranslated region (3′ UTR). The amino acid sequences of the three cloned selenoprotein genes were compared and the redox motifs were found to be present in the amino acid sequences. The results of the phylogenetic tree showed that the three selenoprotein isoforms of yellow catfish Pelteobagrus fulvidraco are closely related to those of Ictalurus punctatus and Danio rerio. The tissue expression profiles showed that the mRNAs of the three selenoprotein genes were expressed in heart, liver, muscle, brain, intestine, spleen, testis and ovaries, but their expression levels were differentially influenced by tissue specificity. In short, these results help us to better understand the relationship between selenoprotein gene isoforms.
s: RACE was used to clone the selenow2a, selenop2 and selenot2 genes with full length cDNAs of 891, 1998 and 1432 bp, respectively, of which the ORFs were 288, 828 and 600 bp in length, encoding 95, 275 and 219 amino acids, respectively. The stop codon encoding selenocysteine was found in the cDNA sequence, and the selenocysteine insertion sequence (SECIS) element was found in the 3′ untranslated region (3′ UTR). The amino acid sequences of the three cloned selenoprotein genes were compared and the redox motifs were found to be present in the amino acid sequences. The results of the phylogenetic tree showed that the three selenoprotein isoforms of yellow catfish Pelteobagrus fulvidraco are closely related to those of Ictalurus punctatus and Danio rerio. The tissue expression profiles showed that the mRNAs of the three selenoprotein genes were expressed in heart, liver, muscle, brain, intestine, spleen, testis and ovaries, but their expression levels were differentially influenced by tissue specificity. In short, these results help us to better understand the relationship between selenoprotein gene isoforms.
Abstract:
In order to better protect and exploit the resources of Triplophysa yarkandensis in the Tarim River basin, based on 348 samples collected in the Qarqan River, a tributary of the Tarim River, from 2019 to 2022, the age structure and growth characteristics of the Triplophysa yarkandensis were studied. The results showed that the collected samples had a body length distribution range of 38-290 mm and a body weight distribution range of 0.8-271.6 g. The age structure was 1-11 years old, and the body length weight relationship equation was W=2.47×10-5L2.8562. Von Bertalanffy growth equation of female: Lt=407.2572[1-e-0.1117(t+0.9298)], Wt=697.2606[1-e-0.1117(t+0.9298)]2.8756; The male1: Lt=327.9114[1-e-0.1572(t+0.7154)], Wt=373.9090[1-e-0.1572(t+0.9298)]2.8353. The apparent growth indexes: ?♀=4.2678, ?♂=4.2280. The inflection point age and corresponding body length and weight for females are: 8.5 years old, 265.63 mm, 204.04 g; Male: 5.9 years old, 212.26 mm, 108.94 g. The results showed that the growth size and natural life of the population of Triplophysa yarkandensis in the Qarqan River was the larger, and the growth rate was faster than that of other tributaries.
In order to better protect and exploit the resources of Triplophysa yarkandensis in the Tarim River basin, based on 348 samples collected in the Qarqan River, a tributary of the Tarim River, from 2019 to 2022, the age structure and growth characteristics of the Triplophysa yarkandensis were studied. The results showed that the collected samples had a body length distribution range of 38-290 mm and a body weight distribution range of 0.8-271.6 g. The age structure was 1-11 years old, and the body length weight relationship equation was W=2.47×10-5L2.8562. Von Bertalanffy growth equation of female: Lt=407.2572[1-e-0.1117(t+0.9298)], Wt=697.2606[1-e-0.1117(t+0.9298)]2.8756; The male1: Lt=327.9114[1-e-0.1572(t+0.7154)], Wt=373.9090[1-e-0.1572(t+0.9298)]2.8353. The apparent growth indexes: ?♀=4.2678, ?♂=4.2280. The inflection point age and corresponding body length and weight for females are: 8.5 years old, 265.63 mm, 204.04 g; Male: 5.9 years old, 212.26 mm, 108.94 g. The results showed that the growth size and natural life of the population of Triplophysa yarkandensis in the Qarqan River was the larger, and the growth rate was faster than that of other tributaries.
Abstract:
Amino acids, vitamin E and lipids are three classes of metabolites with antioxidant activity. In order to analyze the dynamic changes of these metabolites in citrus fruits during the ripening process and evaluate the antioxidant activity of citrus, GC-MS, UPLC and LC-MS/MS were performed to detect the relative contents of three antioxidants during fruit ripening in six citrus varieties. The results showed that serine, proline and aspartic acid accumulated in citrus fruits mainly, the threonine is especially abundant in green fruit, and the total contents of nine amino acids in green pulp of C. chuana ‘Bendizao’ (BDZ) is highest. For vitamin E, α-tocopherol is the primary isomer in citrus, which is abundant in mature colored pericarp. What’s more, there was no accumulation of δ-tocopherol, and γ-tocopherol only exists in the colored pericarp in citrus. A total of eight classes including 176 lipids were identified, which showed obvious temporal and spatial distribution characteristics and phosphatidylcholine is the primary isomer of lipids. Through the correlation calculation of contents between three metabolites, it was found that some amino acids and lipids are highly positively correlated. These results revealed the patterns of accumulation and variation of three important metabolites during fruit ripening in different citrus varieties, which have a guiding significance for the improvement of citrus quality.
Amino acids, vitamin E and lipids are three classes of metabolites with antioxidant activity. In order to analyze the dynamic changes of these metabolites in citrus fruits during the ripening process and evaluate the antioxidant activity of citrus, GC-MS, UPLC and LC-MS/MS were performed to detect the relative contents of three antioxidants during fruit ripening in six citrus varieties. The results showed that serine, proline and aspartic acid accumulated in citrus fruits mainly, the threonine is especially abundant in green fruit, and the total contents of nine amino acids in green pulp of C. chuana ‘Bendizao’ (BDZ) is highest. For vitamin E, α-tocopherol is the primary isomer in citrus, which is abundant in mature colored pericarp. What’s more, there was no accumulation of δ-tocopherol, and γ-tocopherol only exists in the colored pericarp in citrus. A total of eight classes including 176 lipids were identified, which showed obvious temporal and spatial distribution characteristics and phosphatidylcholine is the primary isomer of lipids. Through the correlation calculation of contents between three metabolites, it was found that some amino acids and lipids are highly positively correlated. These results revealed the patterns of accumulation and variation of three important metabolites during fruit ripening in different citrus varieties, which have a guiding significance for the improvement of citrus quality.
Abstract:
To understand the changes in the composition and structure of endophytic bacteria in potato under drought stress, high throughput sequencing of endophytic bacterial 16S rRNA in potato leaves under drought stress was performed using Illumina Novaseq sequencing technology to investigate the effects of drought stress on the composition and diversity of endophytic bacteria in potato leaves. The results showed that 1548 and 2006 taxonomic sequences were obtained from potato leaves under normal watering and drought stress, respectively, with 287 unique OTUs under normal watering and 769 unique OTUs under drought treatment. Under drought stress, the abundance of the endosymbiotic bacteria Candidatus Portiera and Arsenophonus was reduced by 95.9% and 68.1% compared to normal watering, while the abundance of the genera Muribaculaceae, Lachnospira, Lactobacillus, Lachnospiraceae_NK4A136_group, Rhizobium, Helicobacter, Streptococcus and Desulfovibrio increased by 203.8%, 203.8%, 203.8%, 203.8%, 203.8%, 203.8%, 203.8% and 203.8% respectively under drought treatment compared to normal watering. The Shannon and Simpson indices were significantly higher under drought stress than under normal watering, while the ACE and Chao1 indices were not significantly different under drought stress and normal watering.
To understand the changes in the composition and structure of endophytic bacteria in potato under drought stress, high throughput sequencing of endophytic bacterial 16S rRNA in potato leaves under drought stress was performed using Illumina Novaseq sequencing technology to investigate the effects of drought stress on the composition and diversity of endophytic bacteria in potato leaves. The results showed that 1548 and 2006 taxonomic sequences were obtained from potato leaves under normal watering and drought stress, respectively, with 287 unique OTUs under normal watering and 769 unique OTUs under drought treatment. Under drought stress, the abundance of the endosymbiotic bacteria Candidatus Portiera and Arsenophonus was reduced by 95.9% and 68.1% compared to normal watering, while the abundance of the genera Muribaculaceae, Lachnospira, Lactobacillus, Lachnospiraceae_NK4A136_group, Rhizobium, Helicobacter, Streptococcus and Desulfovibrio increased by 203.8%, 203.8%, 203.8%, 203.8%, 203.8%, 203.8%, 203.8% and 203.8% respectively under drought treatment compared to normal watering. The Shannon and Simpson indices were significantly higher under drought stress than under normal watering, while the ACE and Chao1 indices were not significantly different under drought stress and normal watering.
Abstract:
Research Purpose: Covalent attachment of ubiquitin onto lysine residues of the substrate requires the coordinated action of three classes of enzymes: the E1 ubiquitin-activating enzymes, the E2 ubiquitin-conjugating enzymes, and the E3 ubiquitin ligases. These ubiquitination-related proteins play a pivotal role in plant development and plant physiology, Detecting E3 ligase activity in vitro is important for exploring the molecular mechanism of protein ubiquitination. Research method: In this study, we used the APPBP1/UBA3 (E1), UBC12 (E2), Cullin1-Rbx1 (E3) and Nedd8 as an example to reconstitute SCF E3 ligase activity in vitro, Ub (Ubiquitin) labeled with FITC-Cysteine green fluorescein was prepared, which dramatically improved the operability of the in vitro system and provided significant convenience. Result: we used the Cullin1-Rbx1 ligase as an example to reconstitute SCF E3 ligase activity in vitro, which dramatically improved the operability of the in vitro system and provided significant convenience. Conclusion: This method can not only detect the auto-ubiquitination activity of SCF E3 in vitro, but also visualize and quantify the ubiquitination modification, providing a powerful platform for studying the mechanisms of multisubunit SCF E3 ligases in eukaryotes.
Research Purpose: Covalent attachment of ubiquitin onto lysine residues of the substrate requires the coordinated action of three classes of enzymes: the E1 ubiquitin-activating enzymes, the E2 ubiquitin-conjugating enzymes, and the E3 ubiquitin ligases. These ubiquitination-related proteins play a pivotal role in plant development and plant physiology, Detecting E3 ligase activity in vitro is important for exploring the molecular mechanism of protein ubiquitination. Research method: In this study, we used the APPBP1/UBA3 (E1), UBC12 (E2), Cullin1-Rbx1 (E3) and Nedd8 as an example to reconstitute SCF E3 ligase activity in vitro, Ub (Ubiquitin) labeled with FITC-Cysteine green fluorescein was prepared, which dramatically improved the operability of the in vitro system and provided significant convenience. Result: we used the Cullin1-Rbx1 ligase as an example to reconstitute SCF E3 ligase activity in vitro, which dramatically improved the operability of the in vitro system and provided significant convenience. Conclusion: This method can not only detect the auto-ubiquitination activity of SCF E3 in vitro, but also visualize and quantify the ubiquitination modification, providing a powerful platform for studying the mechanisms of multisubunit SCF E3 ligases in eukaryotes.
Abstract:
Taking the purplish soil from the landfill in Yunxi Town, Yanting County, Sichuan Province as the research object, different mass ratios of silicon fertilizer (Si1: 0.5%, Si2: 1.0%) and phosphate rock (P1: 0.2%, P2: 0.4%, P3: 1.0%) compound was added to the soil and passivation cultured for 90 days. To study the changes of available heavy metal content Cd、Cu、Pb、Zn before and after passivation culture, and the soil remediation effect was evaluated by Risk Assessment Code （RAC）. The results showed that high Si treatment (Si2: 1.0%) could significantly reduce the heavy metal effectiveness compared with low Si treatment (Si1: 0.5%), among which, Si2P3 treatment had the highest passivation rates of 30.79%, 27.27%, 27.13% and 36.88% for Cd, Cu, Pb and Zn, respectively; there was no significant difference between Si2P1 and Si2P2 treatments. And Si2P1 treatment could significantly reduce the toxic leaching amount and RAC Risk Assessment Code of heavy metals. The compound passivator mainly promotes the transformation of heavy metals from high activity weak acid extraction state and reducible state to low activity oxidizable state and residue state through the improvement of soil pH and EC values, and the complex-precipitation of functional groups (O-Si-O, Si-O-Si, H2PO4-, PO43-, etc.). On the whole, Si2P1 treatment passivator application amount is lower and more suitable for the remediation of heavy metal contaminated soil in landfills.
Taking the purplish soil from the landfill in Yunxi Town, Yanting County, Sichuan Province as the research object, different mass ratios of silicon fertilizer (Si1: 0.5%, Si2: 1.0%) and phosphate rock (P1: 0.2%, P2: 0.4%, P3: 1.0%) compound was added to the soil and passivation cultured for 90 days. To study the changes of available heavy metal content Cd、Cu、Pb、Zn before and after passivation culture, and the soil remediation effect was evaluated by Risk Assessment Code （RAC）. The results showed that high Si treatment (Si2: 1.0%) could significantly reduce the heavy metal effectiveness compared with low Si treatment (Si1: 0.5%), among which, Si2P3 treatment had the highest passivation rates of 30.79%, 27.27%, 27.13% and 36.88% for Cd, Cu, Pb and Zn, respectively; there was no significant difference between Si2P1 and Si2P2 treatments. And Si2P1 treatment could significantly reduce the toxic leaching amount and RAC Risk Assessment Code of heavy metals. The compound passivator mainly promotes the transformation of heavy metals from high activity weak acid extraction state and reducible state to low activity oxidizable state and residue state through the improvement of soil pH and EC values, and the complex-precipitation of functional groups (O-Si-O, Si-O-Si, H2PO4-, PO43-, etc.). On the whole, Si2P1 treatment passivator application amount is lower and more suitable for the remediation of heavy metal contaminated soil in landfills.
Abstract:
This article proposed an improved YOLOv5s model for detecting dense and highly occluded plums in orchards. Firstly, a new Focus-Maxpool module replaced the down-sampling convolution in the backbone network, enabling the model to retain more feature information of small and highly occluded targets during down-sampling. Secondly, focal loss and weighted cross-entropy functions were used as classification losses to improve the recognition ability of the model for adherent targets. Finally, several tests were designed to evaluate the model's performance. The results showed that the average precision of the improved YOLOv5s model was superior to YOLOv5s, YOLOv4, Faster-RCNN, SSD, and Centernet. Compared with the YOLOv5s model, the improved model's average precision, recall rate, and accuracy had increased by 2.84%, 9.53%, and 1.66%, respectively. Moreover, the detection speed of the improved model could reach 91.37 frames per second, which could meet the real-time detection requirements. The results indicated that the improved detection model had high accuracy and robustness in the natural orchard environment, providing data reference for the research of fruit-picking robots and orchard environmental monitoring.
This article proposed an improved YOLOv5s model for detecting dense and highly occluded plums in orchards. Firstly, a new Focus-Maxpool module replaced the down-sampling convolution in the backbone network, enabling the model to retain more feature information of small and highly occluded targets during down-sampling. Secondly, focal loss and weighted cross-entropy functions were used as classification losses to improve the recognition ability of the model for adherent targets. Finally, several tests were designed to evaluate the model's performance. The results showed that the average precision of the improved YOLOv5s model was superior to YOLOv5s, YOLOv4, Faster-RCNN, SSD, and Centernet. Compared with the YOLOv5s model, the improved model's average precision, recall rate, and accuracy had increased by 2.84%, 9.53%, and 1.66%, respectively. Moreover, the detection speed of the improved model could reach 91.37 frames per second, which could meet the real-time detection requirements. The results indicated that the improved detection model had high accuracy and robustness in the natural orchard environment, providing data reference for the research of fruit-picking robots and orchard environmental monitoring.
Abstract:
Addressing the low automation level in the water-based loading process for basket-loaded eggs in domestic egg processing plants, this paper proposes a visual system solution for an automatic Loading robot. The scheme combines YOLOv5s and image processing to locate and identify basket-loaded eggs in complex environments. A relationship model between the optimal segmentation threshold T and the image"s average gray value M is established, and the dynamic threshold segmentation method is used to segment the entire stack of eggs in the image. The two types of basket-loaded egg stacks are distinguished based on the aspect ratio of the minimum bounding rectangle of the stack. The recognition accuracy of the stack type is 100%. YOLOv5s is used to locate and identify the top egg baskets of the stack, and the model"s recognition precision is 98.48%. The time required to detect a single image is 0.0054s. Based on the positioning results outputted by YOLOv5s, the image is cropped, and the egg basket border is segmented using image segmentation and Canny operators to detect its edge information. The rotation angle of all egg baskets is calculated, with an average angle error of 0.36°, and the pose information of all egg baskets in the basket-loaded eggs stack is determined by combining the basket height. Experimental results show that the basket-loaded eggs positioning method based on YOLOv5s and image processing can accurately identify the pose information of all egg baskets in the stack, and the system has good robustness and feasibility, providing visual system technology support for automatic feeding robots for basket-loaded eggs.
Addressing the low automation level in the water-based loading process for basket-loaded eggs in domestic egg processing plants, this paper proposes a visual system solution for an automatic Loading robot. The scheme combines YOLOv5s and image processing to locate and identify basket-loaded eggs in complex environments. A relationship model between the optimal segmentation threshold T and the image"s average gray value M is established, and the dynamic threshold segmentation method is used to segment the entire stack of eggs in the image. The two types of basket-loaded egg stacks are distinguished based on the aspect ratio of the minimum bounding rectangle of the stack. The recognition accuracy of the stack type is 100%. YOLOv5s is used to locate and identify the top egg baskets of the stack, and the model"s recognition precision is 98.48%. The time required to detect a single image is 0.0054s. Based on the positioning results outputted by YOLOv5s, the image is cropped, and the egg basket border is segmented using image segmentation and Canny operators to detect its edge information. The rotation angle of all egg baskets is calculated, with an average angle error of 0.36°, and the pose information of all egg baskets in the basket-loaded eggs stack is determined by combining the basket height. Experimental results show that the basket-loaded eggs positioning method based on YOLOv5s and image processing can accurately identify the pose information of all egg baskets in the stack, and the system has good robustness and feasibility, providing visual system technology support for automatic feeding robots for basket-loaded eggs.
Abstract:
Filter media filtration can effectively reduce the content of suspended solids and other harmful substances in fish culture tailwater and is often used as a primary treatment technology for aquaculture tailwater. In order to investigate the effect of filter media filtration for pond captive tailwater treatment, this study used volcanic rock, activated carbon and zeolite as the filter media materials, and carried out pond captive tailwater treatment experiments with filter media type, filter media size and filter media thickness as the test factors, and TSS removal rate, ammonia nitrogen removal rate and COD removal rate as the test indexes. The results showed that all three filter media could remove TSS and COD in the tailwater, and all could reduce the concentration of ammonia nitrogen in the tailwater to a certain extent, and among the three filter media, the treatment effect of activated carbon was better than the other two, and the smaller the particle size or the larger the thickness of the filter media, the better the effect of the activated carbon in treating the tailwater. The results of the orthogonal test based on the single-factor test showed that the best overall treatment effect of the filtration device was achieved when the filter media was activated carbon, the particle size was 0.5-2 mm, and the thickness of the filter media was 80 cm. Under these conditions, the removal rates of TSS, COD and ammonia were 83.86%, 49.78% and 29.89%, respectively. The study showed that the filter media filtration has good effect on the removal of TSS and COD, but the ammonia nitrogen removal effect is not satisfactory. Therefore, in the treatment of captive tailwater, media filtration can be used as a primary treatment process for captive tailwater, but further purification of tailwater is needed for ammonia nitrogen by means of biofilter, artificial wetland or bioreactor.
Filter media filtration can effectively reduce the content of suspended solids and other harmful substances in fish culture tailwater and is often used as a primary treatment technology for aquaculture tailwater. In order to investigate the effect of filter media filtration for pond captive tailwater treatment, this study used volcanic rock, activated carbon and zeolite as the filter media materials, and carried out pond captive tailwater treatment experiments with filter media type, filter media size and filter media thickness as the test factors, and TSS removal rate, ammonia nitrogen removal rate and COD removal rate as the test indexes. The results showed that all three filter media could remove TSS and COD in the tailwater, and all could reduce the concentration of ammonia nitrogen in the tailwater to a certain extent, and among the three filter media, the treatment effect of activated carbon was better than the other two, and the smaller the particle size or the larger the thickness of the filter media, the better the effect of the activated carbon in treating the tailwater. The results of the orthogonal test based on the single-factor test showed that the best overall treatment effect of the filtration device was achieved when the filter media was activated carbon, the particle size was 0.5-2 mm, and the thickness of the filter media was 80 cm. Under these conditions, the removal rates of TSS, COD and ammonia were 83.86%, 49.78% and 29.89%, respectively. The study showed that the filter media filtration has good effect on the removal of TSS and COD, but the ammonia nitrogen removal effect is not satisfactory. Therefore, in the treatment of captive tailwater, media filtration can be used as a primary treatment process for captive tailwater, but further purification of tailwater is needed for ammonia nitrogen by means of biofilter, artificial wetland or bioreactor.
Abstract:
In order to enrich the measurement method of raw material storage in the warehouse, improve the level of measurement automation and intelligence, and explore the feasibility of the storage measurement method based on two-dimensional laser radar, a storage measurement device and system based on two-dimensional laser radar scanning were designed. The system used RPLIDAR S1 two-dimensional laser radar scanning to obtain the original point cloud data of material with different storage capacity. The original point cloud was preprocessed by coordinate transformation, overlapping point extraction, filtering, segmentation and other methods. The greedy projection triangulation algorithm was used to reconstruct the preprocessed point cloud to obtain the three-dimensional model of the material in the warehouse. Combined with the three-dimensional model of the material and the bulk density of the material, the storage capacity of the material in the warehouse was obtained, so as to realize the automatic measurement of the storage capacity. Taking corn as the test object, through the verification test of corn storage capacity measurement in small storage tower, through the scanning measurement of different storage capacity of corn, the average absolute error of the measurement results was 8.05 kg, and the average relative error was 1.52 %. The results show that the storage measurement method based on two-dimensional laser radar scanning is feasible, has good stability and measurement accuracy, and can meet the actual needs of production. It provides a new method and technical support for the automatic measurement of material storage in large silos.
In order to enrich the measurement method of raw material storage in the warehouse, improve the level of measurement automation and intelligence, and explore the feasibility of the storage measurement method based on two-dimensional laser radar, a storage measurement device and system based on two-dimensional laser radar scanning were designed. The system used RPLIDAR S1 two-dimensional laser radar scanning to obtain the original point cloud data of material with different storage capacity. The original point cloud was preprocessed by coordinate transformation, overlapping point extraction, filtering, segmentation and other methods. The greedy projection triangulation algorithm was used to reconstruct the preprocessed point cloud to obtain the three-dimensional model of the material in the warehouse. Combined with the three-dimensional model of the material and the bulk density of the material, the storage capacity of the material in the warehouse was obtained, so as to realize the automatic measurement of the storage capacity. Taking corn as the test object, through the verification test of corn storage capacity measurement in small storage tower, through the scanning measurement of different storage capacity of corn, the average absolute error of the measurement results was 8.05 kg, and the average relative error was 1.52 %. The results show that the storage measurement method based on two-dimensional laser radar scanning is feasible, has good stability and measurement accuracy, and can meet the actual needs of production. It provides a new method and technical support for the automatic measurement of material storage in large silos.
Abstract:
To address the problem of low fertilizer utilization due to uneven fertilizer application in traditional fertilizer dischargers, an isotropic double-spiral fertilizer discharger with a double-discharge wheel structure was designed, and the theoretical discharge capacity of the discharger and the parameters affecting the uniformity of fertilizer discharge were determined by theoretical analysis, and a three-factor, three-level Box-Behnken test was conducted with the discharge wheel pitch, center distance, and blade height as test factors, and the fluctuation coefficient of fertilizer discharge uniformity and axial average speed as test indexes. Box-Behnken test. The test results showed that the effects of pitch on uniformity fluctuation coefficient of fertilizer discharge were highly significant (P<0.01), the effects of center distance and blade height on uniformity fluctuation coefficient were significant (0.01
To address the problem of low fertilizer utilization due to uneven fertilizer application in traditional fertilizer dischargers, an isotropic double-spiral fertilizer discharger with a double-discharge wheel structure was designed, and the theoretical discharge capacity of the discharger and the parameters affecting the uniformity of fertilizer discharge were determined by theoretical analysis, and a three-factor, three-level Box-Behnken test was conducted with the discharge wheel pitch, center distance, and blade height as test factors, and the fluctuation coefficient of fertilizer discharge uniformity and axial average speed as test indexes. Box-Behnken test. The test results showed that the effects of pitch on uniformity fluctuation coefficient of fertilizer discharge were highly significant (P<0.01), the effects of center distance and blade height on uniformity fluctuation coefficient were significant (0.01
Abstract:
Biochar is an efficient adsorption carrier for benzene pollutants, but the adsorption capacity of directly carbonized biochar for benzene pollutants is limited. Low-temperature air oxidation is effective in modifying the structure of biochar and enhancing its benzene pollutant adsorption capacity. However, the adsorption behavior and mechanism of low-temperature air oxidation biochar for benzene pollutants still need to be further clarified. Herein, low-temperature air-oxidized biochar was prepared by a two-step activation method using bamboo chips as raw material and CaCl2 as activator. The adsorption processes and behaviors of low-temperature air-oxidized biochar for phenol, aniline, hydroquinone, and p-nitrophenol were analyzed by comprehensive adsorption experiments, biochar structure characterization, and density flooding theory (DFT) calculations. The adsorption properties and mechanisms of oxygen-modified biochar on benzene pollutants were investigated. The results indicated that the adsorption capacities of low-temperature air-oxidized biochar for benzene pollutants were subject to the synergistic effects of biochar pore structure and surface functional groups. The adsorption and storage processes of benzene pollutants were regulated by biochar through the pore filling effect of microporous structure in the spatial geometry scale. Oxygen atoms are assigned to the surface of the carbon skeleton of biochar in the form of hydroxyl, aldehyde and carboxyl groups after the oxidation of biochar by low temperature air. The electronic structure of the carbon skeleton is influenced by the electronic scale, which modifies the adsorption position and type of interaction between the carbon skeleton and benzene pollutants. The adsorption capacities of biochar for benzene pollutants were significantly enhanced by electrostatic gravitational force and hydrogen bonding. In particular, the hydrogen atoms of hydroxyl and carboxyl groups of carbon skeleton are easy to serve as donors for hydrogen bonding, while the oxygen atoms of aldehyde groups are easy to serve as acceptors for hydrogen bonding.
Biochar is an efficient adsorption carrier for benzene pollutants, but the adsorption capacity of directly carbonized biochar for benzene pollutants is limited. Low-temperature air oxidation is effective in modifying the structure of biochar and enhancing its benzene pollutant adsorption capacity. However, the adsorption behavior and mechanism of low-temperature air oxidation biochar for benzene pollutants still need to be further clarified. Herein, low-temperature air-oxidized biochar was prepared by a two-step activation method using bamboo chips as raw material and CaCl2 as activator. The adsorption processes and behaviors of low-temperature air-oxidized biochar for phenol, aniline, hydroquinone, and p-nitrophenol were analyzed by comprehensive adsorption experiments, biochar structure characterization, and density flooding theory (DFT) calculations. The adsorption properties and mechanisms of oxygen-modified biochar on benzene pollutants were investigated. The results indicated that the adsorption capacities of low-temperature air-oxidized biochar for benzene pollutants were subject to the synergistic effects of biochar pore structure and surface functional groups. The adsorption and storage processes of benzene pollutants were regulated by biochar through the pore filling effect of microporous structure in the spatial geometry scale. Oxygen atoms are assigned to the surface of the carbon skeleton of biochar in the form of hydroxyl, aldehyde and carboxyl groups after the oxidation of biochar by low temperature air. The electronic structure of the carbon skeleton is influenced by the electronic scale, which modifies the adsorption position and type of interaction between the carbon skeleton and benzene pollutants. The adsorption capacities of biochar for benzene pollutants were significantly enhanced by electrostatic gravitational force and hydrogen bonding. In particular, the hydrogen atoms of hydroxyl and carboxyl groups of carbon skeleton are easy to serve as donors for hydrogen bonding, while the oxygen atoms of aldehyde groups are easy to serve as acceptors for hydrogen bonding.
Abstract:
In order to deepen the understanding of the spray coating process of preserved eggs, aiming at the problem of insufficient theoretical research on the spray coating of preserved eggs, the two-phase flow research was carried out by using the overlapping grid model coupled with the VOF model in Fluent software. The liquid film wetting ratio during the coating process under different placement positions of preserved eggs was obtained, and the change of the aspect ratio of the droplets under different pipette parameters was analyzed. Taking the film thickness change index as the response value, combined with the Box-Behnken experiment, the optimal pipette parameters and working pressure when the suspended droplets were removed were selected. The results showed that the liquid film wetting ratio of the preserved eggs placed downward after spraying was 1. The wetting ratio of the liquid film of the preserved eggs placed with the blunt end down after spraying was only 0.836. The optimal suction tube parameter combination was screened out as follows : spacing 14.50 mm, diameter 12.09 mm, working pressure 6.97 kPa, and film thickness change index prediction value 0.636. Under the optimal combination of pipe parameters, the simulation experiment was carried out, and the suspension droplet removal experiment was carried out by using the air suction device. The experimental results showed that the relative error between the simulated value and the predicted value of the film thickness variation index was 1.73 %. The relative error between the actual value and the predicted value of the film thickness variation index was 7.55 %, and the relative error with the simulated value was 9.12 %, indicating that the coupling model in this study can be used for the simulation test of egg spray coating.
In order to deepen the understanding of the spray coating process of preserved eggs, aiming at the problem of insufficient theoretical research on the spray coating of preserved eggs, the two-phase flow research was carried out by using the overlapping grid model coupled with the VOF model in Fluent software. The liquid film wetting ratio during the coating process under different placement positions of preserved eggs was obtained, and the change of the aspect ratio of the droplets under different pipette parameters was analyzed. Taking the film thickness change index as the response value, combined with the Box-Behnken experiment, the optimal pipette parameters and working pressure when the suspended droplets were removed were selected. The results showed that the liquid film wetting ratio of the preserved eggs placed downward after spraying was 1. The wetting ratio of the liquid film of the preserved eggs placed with the blunt end down after spraying was only 0.836. The optimal suction tube parameter combination was screened out as follows : spacing 14.50 mm, diameter 12.09 mm, working pressure 6.97 kPa, and film thickness change index prediction value 0.636. Under the optimal combination of pipe parameters, the simulation experiment was carried out, and the suspension droplet removal experiment was carried out by using the air suction device. The experimental results showed that the relative error between the simulated value and the predicted value of the film thickness variation index was 1.73 %. The relative error between the actual value and the predicted value of the film thickness variation index was 7.55 %, and the relative error with the simulated value was 9.12 %, indicating that the coupling model in this study can be used for the simulation test of egg spray coating.
Abstract:
It is extremely important to obtain accurate information of soil moisture content and understand the dynamic change pattern of soil moisture. A support vector machine algorithm (SVM) was introduced for fitting analysis and regression training optimization of ultrasonic velocity and soil moisture content under four different alternating W-D treatments, and a soil moisture content prediction model based on ultrasonic velocity was constructed. The prediction model was applied to the soil water content estimation of farmland tillage layer with different moisture requirements, and the results indicated that the average relative error was about 1.5%. The ultrasonic velocity-soil moisture content prediction model constructed using the SVM model is capable of describing greatly the soil moisture content determination in the studied area, which in turn provides a reference for using the ultrasonic characteristics to achieve continuous monitoring of soil moisture content information of farmland with different moisture management needs.
It is extremely important to obtain accurate information of soil moisture content and understand the dynamic change pattern of soil moisture. A support vector machine algorithm (SVM) was introduced for fitting analysis and regression training optimization of ultrasonic velocity and soil moisture content under four different alternating W-D treatments, and a soil moisture content prediction model based on ultrasonic velocity was constructed. The prediction model was applied to the soil water content estimation of farmland tillage layer with different moisture requirements, and the results indicated that the average relative error was about 1.5%. The ultrasonic velocity-soil moisture content prediction model constructed using the SVM model is capable of describing greatly the soil moisture content determination in the studied area, which in turn provides a reference for using the ultrasonic characteristics to achieve continuous monitoring of soil moisture content information of farmland with different moisture management needs.
Abstract:
[Objective] To explore and utilize the benefit microbes and their functions for developing sustainable agriculture, the effects of different associated crop on endophytic microbial community structure in root of tomatoes were analyzed. [Methods] Five associated crops and monoculture treatments, i.e., tomato×lettuce(A)、tomato×amaranth(B)、tomato×cabbage(C)、tomato×chive(D)、tomato×mint(E) and monoculture(F) were set under the identical conditions in this experiment. And the endophytic microbial community structures in roots of tomatoes were analyzed using MiSeq high-throughput sequencing technology. [Result] Allorhizobium, Neorhizobium, Pararhizobium, Burkholderia, Caballeronia, Paraburkholderia, Devosia, Nocardioides and Streptomyces were the common dominant endophytic bacterial genera in roots of tomatoes under associated and monoculture systems. However, norank_f_Roseiflexaceae and Sphingobium were the special dominant endophytic bacterial genera in roots of tomatoes under tomato x lettuce (A) associated system; Mea nwhile, Amycolatopsis and Herpetosiphon, were also the unique dominant endophytic bacterial genera in roots of tomatoes under tomato x chive (D) associated system. Moreover, Bradyrhizobium and Dyella, were the special dominant endophytic bacterial genera in roots of tomatoes under tomato x mint (E) associated system; By contrast, Flavobacterium was the unique dominant endophytic bacterial genera in roots of tomatoes in monoculture system. In addition, unclassified_p_Ascomycota was the only common dominant endophytic fungal genera in roots of tomatoes under associated and monoculture systems. And lmmersiella was the special dominant endophytic fungal genera in roots of tomatoes under tomato x lettuce (A) associated system; Meanwhile, Arachniotus, Neocosmospora, Penicillium, Phialemonium, and unclassified_c_Agaricomycetes were the unique dominant endophytic fungal genera in roots of tomatoes under tomato x amaranth (B); Geminibasidium, Plectosphaerella and Rhizophagus were the unique dominant endophytic fungal genera in roots of tomatoes under tomato x cabbage (C); Acrocalymma_vagum, Arachniotus_dankaliensis, unclassified_o_Boletales, unclassified_p_Basidiomycota, and unclassified_p_Chytridiomycota were the special dominant endophytic fungal genera in roots of tomatoes under tomato x chive (D); Chaetomium_cochliodes, Neocosmospora_rubicola, Penicillium_simplicissimum were the special dominant endophytic fungal genera in roots of tomatoes under tomato x mint (E); By contrast, Gibberella_intricans was the unique dominant endophytic fungal genera in roots of tomatoes under monoculture system (F). [Conclusion] In comparison with the monoculture of tomato, the compositions of dominant endophytic bacteria and fungi at phylum or genera level in roots of tomatoes all could be altered by associating cultivation with other crops. Meanwhile, the special dominant endophytic bacterial of fungal genera all could be enriched by associating with other crops. In suggested that the anti-biotic or abiotic stresses abilities of tomatoes could be improved by associating with the other 5 different crops in this paper.
[Objective] To explore and utilize the benefit microbes and their functions for developing sustainable agriculture, the effects of different associated crop on endophytic microbial community structure in root of tomatoes were analyzed. [Methods] Five associated crops and monoculture treatments, i.e., tomato×lettuce(A)、tomato×amaranth(B)、tomato×cabbage(C)、tomato×chive(D)、tomato×mint(E) and monoculture(F) were set under the identical conditions in this experiment. And the endophytic microbial community structures in roots of tomatoes were analyzed using MiSeq high-throughput sequencing technology. [Result] Allorhizobium, Neorhizobium, Pararhizobium, Burkholderia, Caballeronia, Paraburkholderia, Devosia, Nocardioides and Streptomyces were the common dominant endophytic bacterial genera in roots of tomatoes under associated and monoculture systems. However, norank_f_Roseiflexaceae and Sphingobium were the special dominant endophytic bacterial genera in roots of tomatoes under tomato x lettuce (A) associated system; Mea nwhile, Amycolatopsis and Herpetosiphon, were also the unique dominant endophytic bacterial genera in roots of tomatoes under tomato x chive (D) associated system. Moreover, Bradyrhizobium and Dyella, were the special dominant endophytic bacterial genera in roots of tomatoes under tomato x mint (E) associated system; By contrast, Flavobacterium was the unique dominant endophytic bacterial genera in roots of tomatoes in monoculture system. In addition, unclassified_p_Ascomycota was the only common dominant endophytic fungal genera in roots of tomatoes under associated and monoculture systems. And lmmersiella was the special dominant endophytic fungal genera in roots of tomatoes under tomato x lettuce (A) associated system; Meanwhile, Arachniotus, Neocosmospora, Penicillium, Phialemonium, and unclassified_c_Agaricomycetes were the unique dominant endophytic fungal genera in roots of tomatoes under tomato x amaranth (B); Geminibasidium, Plectosphaerella and Rhizophagus were the unique dominant endophytic fungal genera in roots of tomatoes under tomato x cabbage (C); Acrocalymma_vagum, Arachniotus_dankaliensis, unclassified_o_Boletales, unclassified_p_Basidiomycota, and unclassified_p_Chytridiomycota were the special dominant endophytic fungal genera in roots of tomatoes under tomato x chive (D); Chaetomium_cochliodes, Neocosmospora_rubicola, Penicillium_simplicissimum were the special dominant endophytic fungal genera in roots of tomatoes under tomato x mint (E); By contrast, Gibberella_intricans was the unique dominant endophytic fungal genera in roots of tomatoes under monoculture system (F). [Conclusion] In comparison with the monoculture of tomato, the compositions of dominant endophytic bacteria and fungi at phylum or genera level in roots of tomatoes all could be altered by associating cultivation with other crops. Meanwhile, the special dominant endophytic bacterial of fungal genera all could be enriched by associating with other crops. In suggested that the anti-biotic or abiotic stresses abilities of tomatoes could be improved by associating with the other 5 different crops in this paper.
Abstract:
Mushroom sticks need to replenish water one by one for many times in the process of mushroom production. Aiming at the problems of high labor intensity, low efficiency and inability to accurately control the water injection volume of traditional manual water replenishment, this paper innovatively designs a water injection machine for mushroom sticks on the rack, which is mainly composed of six parts: clamping device, water injection device, lifting device, rotating device, driving device and positioning device. The water injection unit is composed of three groups of clamping devices and water injection devices, which can simultaneously complete the clamping and water injection of 15 mushroom sticks in three layers. Driven by the lifting device, the multi-layer mushroom sticks can be used to replenish water, and then the other side of the tunnel can be used to replenish water on the rack through the rotary device. The prototype test results show that the damage rate of the bacteria rod after water supplement is 0%, the average weight ratio is 84.8%, and the average water supplement efficiency is 270 pieces/h. The water injection machine adopts the method of filling water with mushroom sticks on the rack, which improves the working efficiency, reduces the labor intensity, meets the requirements of filling water with mushroom sticks, and provides a theoretical basis for the research and development of mushroom stick water injection machine.
Mushroom sticks need to replenish water one by one for many times in the process of mushroom production. Aiming at the problems of high labor intensity, low efficiency and inability to accurately control the water injection volume of traditional manual water replenishment, this paper innovatively designs a water injection machine for mushroom sticks on the rack, which is mainly composed of six parts: clamping device, water injection device, lifting device, rotating device, driving device and positioning device. The water injection unit is composed of three groups of clamping devices and water injection devices, which can simultaneously complete the clamping and water injection of 15 mushroom sticks in three layers. Driven by the lifting device, the multi-layer mushroom sticks can be used to replenish water, and then the other side of the tunnel can be used to replenish water on the rack through the rotary device. The prototype test results show that the damage rate of the bacteria rod after water supplement is 0%, the average weight ratio is 84.8%, and the average water supplement efficiency is 270 pieces/h. The water injection machine adopts the method of filling water with mushroom sticks on the rack, which improves the working efficiency, reduces the labor intensity, meets the requirements of filling water with mushroom sticks, and provides a theoretical basis for the research and development of mushroom stick water injection machine.
Abstract:
Aiming at the existing problems of poor stability of furrow width, low flatness of furrow bottom and large soil disturbance in the operation of furrow opener device of rapeseed matrix block seedling transplanting machine, which leads to low seedling rate and difficult soil covering operation, this paper designs a kind of seedbed belt preparation device suitable for the construction of rapeseed matrix block seedling transplanting machine based on the large cavity of ship type furrow opener and the characteristics of wide seedbed and flat furrow bottom constructed by core ploughshare furrow opener operation, combined with the excessive connection of ploughshare surface. The mechanical model of the interaction between the soil and the preparation device was established, and the main structural parameters of the stable seedbed were determined. Taking the working speed, working depth, front-end width and edge angle of the surface as the factors, the soil disturbance area and the coefficient of variation of the ditch width as the evaluation indexes, the four-factor and three-level quadratic orthogonal combination simulation test was carried out by EDEM. The quadratic orthogonal combination test showed that when the working depth was 41 mm, the working speed was 0.52 m / s, the width of the front end of the like-share curved surface was 40 mm, and the blade angle was 61 o, the soil disturbance amount was small and the coefficient of variation of the ditch width was small. The bench test under the optimal parameter combination showed that the soil disturbance amount was 13.01 cm2 and the coefficient of variation of the ditch width was 8.52 %. The results of field comparative test showed that compared with the ship opener, the seedling bed preparation device installed on the transplanting unit increased the seedling rate of the seedling matrix block by 2.09 %, the coefficient of variation of the ditch width decreased by 13.3 %, the soil disturbance decreased by 28.3 %, and the compactness of the bottom surface of the ditch increased by 28.67 %, which met the requirements of the mechanical transplanting of rapeseed matrix seedlings.
Aiming at the existing problems of poor stability of furrow width, low flatness of furrow bottom and large soil disturbance in the operation of furrow opener device of rapeseed matrix block seedling transplanting machine, which leads to low seedling rate and difficult soil covering operation, this paper designs a kind of seedbed belt preparation device suitable for the construction of rapeseed matrix block seedling transplanting machine based on the large cavity of ship type furrow opener and the characteristics of wide seedbed and flat furrow bottom constructed by core ploughshare furrow opener operation, combined with the excessive connection of ploughshare surface. The mechanical model of the interaction between the soil and the preparation device was established, and the main structural parameters of the stable seedbed were determined. Taking the working speed, working depth, front-end width and edge angle of the surface as the factors, the soil disturbance area and the coefficient of variation of the ditch width as the evaluation indexes, the four-factor and three-level quadratic orthogonal combination simulation test was carried out by EDEM. The quadratic orthogonal combination test showed that when the working depth was 41 mm, the working speed was 0.52 m / s, the width of the front end of the like-share curved surface was 40 mm, and the blade angle was 61 o, the soil disturbance amount was small and the coefficient of variation of the ditch width was small. The bench test under the optimal parameter combination showed that the soil disturbance amount was 13.01 cm2 and the coefficient of variation of the ditch width was 8.52 %. The results of field comparative test showed that compared with the ship opener, the seedling bed preparation device installed on the transplanting unit increased the seedling rate of the seedling matrix block by 2.09 %, the coefficient of variation of the ditch width decreased by 13.3 %, the soil disturbance decreased by 28.3 %, and the compactness of the bottom surface of the ditch increased by 28.67 %, which met the requirements of the mechanical transplanting of rapeseed matrix seedlings.
Abstract:
In order to solve the problems of high labor intensity, low efficiency and difficult separation of fruit and soil during dry harvesting of water chestnut, a vibration extrusion type water chestnut harvester was designed to improve the degree of separation of fruit and soil by enhancing the effect of soil fragmentation. The separated water chestnut was scattered on the surface for easy manual picking up. Through the stress analysis of water chestnut soil block in the process of operation, the key parameters affecting the separation performance are determined as vibration plate amplitude, vibration frequency of vibration plate and rotation speed of nail roller, and the value range of key parameters is preliminarily determined according to the existing experience. Taking the vibration amplitude of the vibration plate, the vibration frequency of the vibration plate and the rotation speed of the nail roller as the influencing factors, taking the soil layer breaking rate as the evaluation index, using Design-Expert 10.0 to design the CCD center combination test, and through the simulation of the RecurDyn-EDM coupling, it is determined that when the vibration frequency of the vibration extrusion plate is 33.045mm, the vibration frequency of the vibration plate is 6.631Hz, and the rotation speed of the nail roller is 336.721r/min Hz, there is a better breaking effect, and the soil layer breaking rate is 93.581%. The field verification test was carried out with the actual amplitude of vibration plate 32.41 mm, vibration frequency 6.5 Hz, and nail tooth rolling speed 330 r/min, and the results showed that the actual soil layer breaking rate was 93.546%, the Mingfa rate was 80.334%, and the damage rate was 28.088%. The soil breaking effect was good, and the fitting degree with the simulation results was high.
In order to solve the problems of high labor intensity, low efficiency and difficult separation of fruit and soil during dry harvesting of water chestnut, a vibration extrusion type water chestnut harvester was designed to improve the degree of separation of fruit and soil by enhancing the effect of soil fragmentation. The separated water chestnut was scattered on the surface for easy manual picking up. Through the stress analysis of water chestnut soil block in the process of operation, the key parameters affecting the separation performance are determined as vibration plate amplitude, vibration frequency of vibration plate and rotation speed of nail roller, and the value range of key parameters is preliminarily determined according to the existing experience. Taking the vibration amplitude of the vibration plate, the vibration frequency of the vibration plate and the rotation speed of the nail roller as the influencing factors, taking the soil layer breaking rate as the evaluation index, using Design-Expert 10.0 to design the CCD center combination test, and through the simulation of the RecurDyn-EDM coupling, it is determined that when the vibration frequency of the vibration extrusion plate is 33.045mm, the vibration frequency of the vibration plate is 6.631Hz, and the rotation speed of the nail roller is 336.721r/min Hz, there is a better breaking effect, and the soil layer breaking rate is 93.581%. The field verification test was carried out with the actual amplitude of vibration plate 32.41 mm, vibration frequency 6.5 Hz, and nail tooth rolling speed 330 r/min, and the results showed that the actual soil layer breaking rate was 93.546%, the Mingfa rate was 80.334%, and the damage rate was 28.088%. The soil breaking effect was good, and the fitting degree with the simulation results was high.
Effects of associated cultivation on soil fertility and microbial diversity in rhizospheres tomatoes
Abstract:
To investigate the mechanisms of associated cultivations on soil fertility and health, soil biological properties and microbial diversity in rhizospheres of tomatoes under associated systems were analyzed. The results showed that soil enzyme activities, such as Aminopeptidases and Phosphatase, and the soil microbial biomass carbon, nitrogen and phosphorus in rhizospheres of tomatoes were all significantly improved by associated cultivation with four associated crops except of flowering cabbages. In addition, although soil microbial diversities were not significantly improved by associated cultivations, but the proportions of microbial abundance at phylum or genus levels were altered. For example, the dominant bacteria at phylum level the abundances of Proteobacteria, Patescibacteria, and Firmicutes could be promoted by associated cultivations; Meanwhile, norank_f__Microscillaceae, norank_f__norank_o__ Vicinamibacterales, Bacillus, norank_f__Gemmatimonadaceae, and Altererythrobacter were the top ten dominant bacterial genera in rhizospheres of tomatoes under associated systems. Furthermore, compared with monoculture of tomato, soil fungal diversity and richness in rhizospheres of tomatoes under associated systems were also altered. Such as Phaeophyta, Streptomyces and Oleaginous at phylum level and unclassified_o__Sordariales, Olpidium,Conocybe, Phialemonium, unclassified_o__Pleosporales, unclassified_o__Boletales and Sodiomyces at genus levels not only enriched, but also the abundance of Chaetomium increases under associated systems. In conclusions, except of flowering cabbage, soil fertility and health in rhizospheres of tomatoes were all improved or maintained by associated cultivating with lettuce, amaranth, mint and green onion. In comparison to flowering cabbage, amaranth and green onion, lettuce and mint were the suitable associated crops for tomato.
To investigate the mechanisms of associated cultivations on soil fertility and health, soil biological properties and microbial diversity in rhizospheres of tomatoes under associated systems were analyzed. The results showed that soil enzyme activities, such as Aminopeptidases and Phosphatase, and the soil microbial biomass carbon, nitrogen and phosphorus in rhizospheres of tomatoes were all significantly improved by associated cultivation with four associated crops except of flowering cabbages. In addition, although soil microbial diversities were not significantly improved by associated cultivations, but the proportions of microbial abundance at phylum or genus levels were altered. For example, the dominant bacteria at phylum level the abundances of Proteobacteria, Patescibacteria, and Firmicutes could be promoted by associated cultivations; Meanwhile, norank_f__Microscillaceae, norank_f__norank_o__ Vicinamibacterales, Bacillus, norank_f__Gemmatimonadaceae, and Altererythrobacter were the top ten dominant bacterial genera in rhizospheres of tomatoes under associated systems. Furthermore, compared with monoculture of tomato, soil fungal diversity and richness in rhizospheres of tomatoes under associated systems were also altered. Such as Phaeophyta, Streptomyces and Oleaginous at phylum level and unclassified_o__Sordariales, Olpidium,Conocybe, Phialemonium, unclassified_o__Pleosporales, unclassified_o__Boletales and Sodiomyces at genus levels not only enriched, but also the abundance of Chaetomium increases under associated systems. In conclusions, except of flowering cabbage, soil fertility and health in rhizospheres of tomatoes were all improved or maintained by associated cultivating with lettuce, amaranth, mint and green onion. In comparison to flowering cabbage, amaranth and green onion, lettuce and mint were the suitable associated crops for tomato.
Display Method:
Abstract:
In this study,we investigated the effect of bio-floating bed on growth and muscle quality of grass carp (Ctenopharyngodon idellus) and blunt snout bream(Megalobrama amblycephala) in ponds.Two modes of culture ponds were chosen:one equipped with bio-floating bed was the experimental pond,and the other without beds was the control pond.At the end of the experiment,we measured the growth parameters,the muscle conventional nutrients,water holding capacity (WHC),and texture characteristics using biochemical and physical methods.The results showed that the final weight of fish cultured in the experimental pond was higher than that in the control pond.The hepatic somatic index of grass carp (1.77%) in the experimental pond was significantly lower than that of the control (2.47%).The condition factors of grass carp and blunt snout bream (1.73 and 2.56,respectively) were significantly higher than those of the control (1.64 and 2.40,respectively).There was no significant difference in the eviscerated weight of both carp and bream between the experimental (91.06 and 88.28,respectively) and the control (89.22 and 88.49,respectively) ponds.The drop loss (14.49% and 10.69,respectively) and water loss rate (17.52% and 10.34%,respectively) of the experimental grass carp and blunt snout bream were significantly lower than those of the control.The cooked rate of the experimental fish was significantly higher than the control.The muscle crude fat content (1.89%) and crude protein content (14.60%) of grass carp in the experimental ponds were significantly higher than those of the control (1.54% and 13.46%),whereas muscle water content (81.68%) of the experimental fish was significantly lower than that (82.65%) of the control.There is no significant difference in muscle ash content between the two groups.Unlike grass carp,only muscle crude protein content (17.23%) of the experimental bream was significantly higher than that (15.90%) of the control.The muscular hardness,gumminess,and chewiness of the experimental carp (5 298.10 g,2 450.78 g and 770.78 g,respectively) were significantly higher than those of the control (3 226.79 g,1 881.43 g and 602.80 g,respectively).The resilience (0.31) and cohesion (0.48) of experimental carp were significantly lower than those (0.43 and 0.58,respectively) of the control.However,only the muscular springiness of the blunt snout bream in the experimental pond was significantly higher than that in the control pond.
In this study,we investigated the effect of bio-floating bed on growth and muscle quality of grass carp (Ctenopharyngodon idellus) and blunt snout bream(Megalobrama amblycephala) in ponds.Two modes of culture ponds were chosen:one equipped with bio-floating bed was the experimental pond,and the other without beds was the control pond.At the end of the experiment,we measured the growth parameters,the muscle conventional nutrients,water holding capacity (WHC),and texture characteristics using biochemical and physical methods.The results showed that the final weight of fish cultured in the experimental pond was higher than that in the control pond.The hepatic somatic index of grass carp (1.77%) in the experimental pond was significantly lower than that of the control (2.47%).The condition factors of grass carp and blunt snout bream (1.73 and 2.56,respectively) were significantly higher than those of the control (1.64 and 2.40,respectively).There was no significant difference in the eviscerated weight of both carp and bream between the experimental (91.06 and 88.28,respectively) and the control (89.22 and 88.49,respectively) ponds.The drop loss (14.49% and 10.69,respectively) and water loss rate (17.52% and 10.34%,respectively) of the experimental grass carp and blunt snout bream were significantly lower than those of the control.The cooked rate of the experimental fish was significantly higher than the control.The muscle crude fat content (1.89%) and crude protein content (14.60%) of grass carp in the experimental ponds were significantly higher than those of the control (1.54% and 13.46%),whereas muscle water content (81.68%) of the experimental fish was significantly lower than that (82.65%) of the control.There is no significant difference in muscle ash content between the two groups.Unlike grass carp,only muscle crude protein content (17.23%) of the experimental bream was significantly higher than that (15.90%) of the control.The muscular hardness,gumminess,and chewiness of the experimental carp (5 298.10 g,2 450.78 g and 770.78 g,respectively) were significantly higher than those of the control (3 226.79 g,1 881.43 g and 602.80 g,respectively).The resilience (0.31) and cohesion (0.48) of experimental carp were significantly lower than those (0.43 and 0.58,respectively) of the control.However,only the muscular springiness of the blunt snout bream in the experimental pond was significantly higher than that in the control pond.
Abstract:
Effects of soaking temperature,cultivation temperature and watering frequency on the growth characteristics and nutrition of mung bean sprout were investigated. Growth characteristics and nutrition of mung bean sprout were significantly affected by soaking temperature,cultivation temperature and watering frequency (P<0.05). When the bean was soaked at higher temperature (40℃),body weight of the cultivated mung bean sprout was heavier,hypocotyl was longer,contents of free amino acid (FAA),water soluble sugar (WSS) and γ-aminobutyric acid (GABA) were higher. The hypocotyl was longer while the diameter was smaller when the bean was cultivated in the relatively higher temperature (30-35℃). When the watering frequency decreased,weight,hypocotyl length and diameter decreased,WSS content decreased first and then increased,FAA content increased first and then decreased,GABA content was fluctuated. The optimal germination conditions of mung bean sprout were soaking bean at 40℃ for 5 h,with cultivation temperature of 25-30℃ and watering once per hour.
Effects of soaking temperature,cultivation temperature and watering frequency on the growth characteristics and nutrition of mung bean sprout were investigated. Growth characteristics and nutrition of mung bean sprout were significantly affected by soaking temperature,cultivation temperature and watering frequency (P<0.05). When the bean was soaked at higher temperature (40℃),body weight of the cultivated mung bean sprout was heavier,hypocotyl was longer,contents of free amino acid (FAA),water soluble sugar (WSS) and γ-aminobutyric acid (GABA) were higher. The hypocotyl was longer while the diameter was smaller when the bean was cultivated in the relatively higher temperature (30-35℃). When the watering frequency decreased,weight,hypocotyl length and diameter decreased,WSS content decreased first and then increased,FAA content increased first and then decreased,GABA content was fluctuated. The optimal germination conditions of mung bean sprout were soaking bean at 40℃ for 5 h,with cultivation temperature of 25-30℃ and watering once per hour.
2013,32(4):48-54, DOI: 1000-2421（2013）04-0048-07
Abstract:
The spatial distribution of Valley County land use degree in 2009 was studied and the spatial autocorrelation of land use degree and its driving factors in different scales were analyzed.A spatial autoregressive model and geographically weighted regression model was established from the perspective of global local.The results showed that there was a certain spatial autocorrelation in land use degree and its driving factors with scale effect.Spatial regression model could estimate the overall parameter of various factors while geographically weighted regression model could give the local parameter of various factors.Scales of geographical weighted regression model could reflect the detailed geographical information to some extent.
The spatial distribution of Valley County land use degree in 2009 was studied and the spatial autocorrelation of land use degree and its driving factors in different scales were analyzed.A spatial autoregressive model and geographically weighted regression model was established from the perspective of global local.The results showed that there was a certain spatial autocorrelation in land use degree and its driving factors with scale effect.Spatial regression model could estimate the overall parameter of various factors while geographically weighted regression model could give the local parameter of various factors.Scales of geographical weighted regression model could reflect the detailed geographical information to some extent.
Abstract:
pCB302-3 is a plant mini-binary stable transformation vector.To investigate the transient expression of pCB302-3 vector in plant,GFP was inserted into pCB302-3 vector as a reporter gene,and various factors including density of Agrobacterium cell,supplementation of gene silencing suppression p19 and days post infiltration were optimized based on agroinfiltration method in Nicotiana benthamiana leaves.Results showed that high levels of GFP expression were observed in N.benthamiana leaves 3-5 d after infiltration by Agrobacterium cell suspension contained pCB302-3-GFP with an optical density （D600） of 0.8-1.0 co-infiltrated with p19 gene.
pCB302-3 is a plant mini-binary stable transformation vector.To investigate the transient expression of pCB302-3 vector in plant,GFP was inserted into pCB302-3 vector as a reporter gene,and various factors including density of Agrobacterium cell,supplementation of gene silencing suppression p19 and days post infiltration were optimized based on agroinfiltration method in Nicotiana benthamiana leaves.Results showed that high levels of GFP expression were observed in N.benthamiana leaves 3-5 d after infiltration by Agrobacterium cell suspension contained pCB302-3-GFP with an optical density （D600） of 0.8-1.0 co-infiltrated with p19 gene.
2012,31(1):16-22, DOI: 1000-2421（2012）01-0016-07
Abstract:
Nitrogen is one of essential nutrients for plant growth.Under the N deficiency at different time points，the dynamic changes of the expression of genes and activity of enzymes related to nitrogen assimilation in rice were investigated.The results showed that the concentrations of ammonium and nitrate significantly reduced under the N deficiency.Under the N deficiency for a short time，the expression level of genes including NR1, NR2, NiR2,GS2,Fd-GOGAT,GDH2,GDH3 in the shoots as well as NR1,NR2,GDH4 in the roots were up-regulated,and then their expression level decreased after a long time under the N deficiency.Along with the extension of time under the N deficiency,the GS,Fd-GOGAT activities in whole plants,NR activity in shoots and NADH-GOGAT activity in roots decreased while the NADPH-GDH activity in shoots increased.In roots the activities of NR,GDH increased at first and then decreased，while in shoots the NiR activity was just the opposite.Re-supplied N after 7 days of N deficiency,the transcriptional expression level and enzyme activities of NR,NiR,GS,GOGAT,GDH restored,and expression level of some genes increased as well.
Nitrogen is one of essential nutrients for plant growth.Under the N deficiency at different time points，the dynamic changes of the expression of genes and activity of enzymes related to nitrogen assimilation in rice were investigated.The results showed that the concentrations of ammonium and nitrate significantly reduced under the N deficiency.Under the N deficiency for a short time，the expression level of genes including NR1, NR2, NiR2,GS2,Fd-GOGAT,GDH2,GDH3 in the shoots as well as NR1,NR2,GDH4 in the roots were up-regulated,and then their expression level decreased after a long time under the N deficiency.Along with the extension of time under the N deficiency,the GS,Fd-GOGAT activities in whole plants,NR activity in shoots and NADH-GOGAT activity in roots decreased while the NADPH-GDH activity in shoots increased.In roots the activities of NR,GDH increased at first and then decreased，while in shoots the NiR activity was just the opposite.Re-supplied N after 7 days of N deficiency,the transcriptional expression level and enzyme activities of NR,NiR,GS,GOGAT,GDH restored,and expression level of some genes increased as well.
2013,32(5):124-133, DOI: 1000-2421（2013）05-0124-10
Abstract:
Bacterial canker is a devastating disease of kiwifruit. In recent years,the disease is showing a tendency to outbreak in such countries as Italy and New Zealand,where kiwifruit is a major crop,and has the trends to further spread worldwide,which will be a serious threat to the development of the kiwifruit industry. Based on the latest research reports, this paper summarized the symptoms,pathogen identification,rapid detection methods,virulence differences,infected mechanism,epidemiology and control technology of the disease. Meanwhile,the future research prospect of kiwifruit bacterial canker was also discussed in order to reduce the loss and risk of the kiwifruit industry.
Bacterial canker is a devastating disease of kiwifruit. In recent years,the disease is showing a tendency to outbreak in such countries as Italy and New Zealand,where kiwifruit is a major crop,and has the trends to further spread worldwide,which will be a serious threat to the development of the kiwifruit industry. Based on the latest research reports, this paper summarized the symptoms,pathogen identification,rapid detection methods,virulence differences,infected mechanism,epidemiology and control technology of the disease. Meanwhile,the future research prospect of kiwifruit bacterial canker was also discussed in order to reduce the loss and risk of the kiwifruit industry.
Abstract:
In order to overcome the transition，field operation, and standardized batch production difficulties of the existing track cargo vehicle in mountainous orchard, as well as to raise the utilization rate, the mountain orchard detachable unidirectional traction double track cargo vehicle was developed. This paper introduced the whole machine structure, the wire rope diameter selection，the minimum track inclination，the maximum track distance，the minimum track turning radius and the working principle of the rope brake device. Load experiments were carried out to test the cargo′s synthetic track function. It is indicated by calculation that the wire rope diameter should be 7.7 mm，the minimum track inclination was 5.7°, the maximum track distance was 170 m, the minimum track horizontal turning radius was 7 m, and the minimum track vertical turning radius was 2 m. Load experiment results indicated that the cargo vehicle′s uplink average speed was 0.51 m/s, the downlink average speed was 0.54 m/s, the average energy consumption was 1.235 kW·h and the effective use degree was 100%. This cargo vehicle was suitable for fruit, pesticide, chemical fertilizer and other cargo transportation in the mountain orchard. Meanwhile, it can be applied to carry the spraying machine, the shave machine and other agricultural machines.
In order to overcome the transition，field operation, and standardized batch production difficulties of the existing track cargo vehicle in mountainous orchard, as well as to raise the utilization rate, the mountain orchard detachable unidirectional traction double track cargo vehicle was developed. This paper introduced the whole machine structure, the wire rope diameter selection，the minimum track inclination，the maximum track distance，the minimum track turning radius and the working principle of the rope brake device. Load experiments were carried out to test the cargo′s synthetic track function. It is indicated by calculation that the wire rope diameter should be 7.7 mm，the minimum track inclination was 5.7°, the maximum track distance was 170 m, the minimum track horizontal turning radius was 7 m, and the minimum track vertical turning radius was 2 m. Load experiment results indicated that the cargo vehicle′s uplink average speed was 0.51 m/s, the downlink average speed was 0.54 m/s, the average energy consumption was 1.235 kW·h and the effective use degree was 100%. This cargo vehicle was suitable for fruit, pesticide, chemical fertilizer and other cargo transportation in the mountain orchard. Meanwhile, it can be applied to carry the spraying machine, the shave machine and other agricultural machines.
2014,33(2):139-144, DOI: 1000-2421（2014）02-0139-06
Abstract:
Algae are lower photosynthetic autotrophs which have close relationship with agricultural activities.With the deep understanding of physiological and ecological characteristics,algae have used more and more widelyin the practice of agricultural activities.This paper reviews the application of algaeas a resourcein agricultural activities including improvement of agricultural environment,utilized as food or food additives and health care products,as well as feed or bait.
Algae are lower photosynthetic autotrophs which have close relationship with agricultural activities.With the deep understanding of physiological and ecological characteristics,algae have used more and more widelyin the practice of agricultural activities.This paper reviews the application of algaeas a resourcein agricultural activities including improvement of agricultural environment,utilized as food or food additives and health care products,as well as feed or bait.
Abstract:
The development of Golden Rice to date has taken longer than anticipated.It has been proven to have the potential to assist in the alleviation of an important public health problem,vitamin A deficiency,affecting millions.Complying with the highly precautionary,and now proven unnecessary,UN Cartagena Protocol for Biosafety has impeded scientific progress and scientific collaboration,particularly by delaying the selection of phenotypes grown in the open field.So far therefore,Golden Rice has not been able to assist in combatting vitamin A deficiency,identified by the UN as an important public health target for 25 years,and which continues to cause preventable deaths and blindness.However,the inventor’s original vision of the donation of the technology to assist the resource poor who want to benefit from it remains firm and achievable,subject to continuing philanthropic and public sector funding.
The development of Golden Rice to date has taken longer than anticipated.It has been proven to have the potential to assist in the alleviation of an important public health problem,vitamin A deficiency,affecting millions.Complying with the highly precautionary,and now proven unnecessary,UN Cartagena Protocol for Biosafety has impeded scientific progress and scientific collaboration,particularly by delaying the selection of phenotypes grown in the open field.So far therefore,Golden Rice has not been able to assist in combatting vitamin A deficiency,identified by the UN as an important public health target for 25 years,and which continues to cause preventable deaths and blindness.However,the inventor’s original vision of the donation of the technology to assist the resource poor who want to benefit from it remains firm and achievable,subject to continuing philanthropic and public sector funding.
2012,31(5):569-573, DOI: 1000-2421（2012）05-0569-05
Abstract:
Hydroponic experiments of strawberry were conducted with three formulations of nutrient solution to select the best formulations for soilless cultivation of strawberry.Several main characteristics of growth including the fresh weight and dry weight of overground plant and root，the growth of crown，the photosynthetic and quality of strawberry，the diameter of staminate flower，the growth amass were investigated．The results showed that the effect of nutrient solution with the content of calcium nitrate tetrahydrate,potassium nitrate,ammonium dihydrogen phosphate,magnesium sulfate and ammonium nitrate at 295,303,62,246,0 mg/L on the growing status and fruit quality of strawberry are better than that of the other 2 treatments.This nutrient solution formula was the most propitious for the growth of ‘Jingyao’ strawberry and the enhancement of the fruit quality among the three different treatnments.That is,it facilitated the growth of strawberry in alimentation growth periods,and the leaves of ‘Jingyao’ strawberry was larger and thicker with a dark-green color,and the diameter of the pedicel was also larger. In addition,the nutrient solution formula was also conducive to the flowering promotion and the reproductive growth of strawberry,and resultes showed that the single fruit weight,yield and fruit quality is the best comparing to the other treatments.The results of this study provided academic and technological basis for establishing high yield and quality of strawberry in greenhouse substrate culture of irrigation and nitrogen application system.
Hydroponic experiments of strawberry were conducted with three formulations of nutrient solution to select the best formulations for soilless cultivation of strawberry.Several main characteristics of growth including the fresh weight and dry weight of overground plant and root，the growth of crown，the photosynthetic and quality of strawberry，the diameter of staminate flower，the growth amass were investigated．The results showed that the effect of nutrient solution with the content of calcium nitrate tetrahydrate,potassium nitrate,ammonium dihydrogen phosphate,magnesium sulfate and ammonium nitrate at 295,303,62,246,0 mg/L on the growing status and fruit quality of strawberry are better than that of the other 2 treatments.This nutrient solution formula was the most propitious for the growth of ‘Jingyao’ strawberry and the enhancement of the fruit quality among the three different treatnments.That is,it facilitated the growth of strawberry in alimentation growth periods,and the leaves of ‘Jingyao’ strawberry was larger and thicker with a dark-green color,and the diameter of the pedicel was also larger. In addition,the nutrient solution formula was also conducive to the flowering promotion and the reproductive growth of strawberry,and resultes showed that the single fruit weight,yield and fruit quality is the best comparing to the other treatments.The results of this study provided academic and technological basis for establishing high yield and quality of strawberry in greenhouse substrate culture of irrigation and nitrogen application system.
2012,31(1):127-132, DOI: 1000-2421（2012）01-0127-06
Abstract:
Post-harvest strawberries are susceptible to the decay of fruit and deterioration of quality due to pathogenic fungi infections,a main factor leading to economic losses for both growers and retailers.With the increase of strawberries planting in China,it is urgent to effectively reduce post-harvest rots of strawberry fruits.In this review,new management developments for controlling fungal diseases in post-harvest strawberry were summarized in terms of physical,chemical and biological approaches,which can help to extend the on-shelf time of strawberry fruits.
Post-harvest strawberries are susceptible to the decay of fruit and deterioration of quality due to pathogenic fungi infections,a main factor leading to economic losses for both growers and retailers.With the increase of strawberries planting in China,it is urgent to effectively reduce post-harvest rots of strawberry fruits.In this review,new management developments for controlling fungal diseases in post-harvest strawberry were summarized in terms of physical,chemical and biological approaches,which can help to extend the on-shelf time of strawberry fruits.
Abstract:
Using Mesorhizobium sp.S-15 and Paenibacillus sp.S-17 as experimental strains.After cell disruption,NH4OAc extraction,H2O2 solution digestion or without any pre-treatment,K+ content in the fermentation broth of potassium solubilizing bacteria was determined with flame photometer.The efficiency of K solubilizing by potassium solubilizing bacteria in the culture medium was calculated.The results showed that the standard curves of the three kinds of K series of standard solutions were similar with the R2 values of 0.994 4,0.999 7 and 0.999 8,respectively.After digested by H2O2 solution,concentration of K+ was detected.The efficiency of two strains was 101.1% and 125.1%,significantly higher than that of other groups.The efficiency of potassium solubilizing detected after H2O2 digestion well reflected potassium solubilization of bacteria.
Using Mesorhizobium sp.S-15 and Paenibacillus sp.S-17 as experimental strains.After cell disruption,NH4OAc extraction,H2O2 solution digestion or without any pre-treatment,K+ content in the fermentation broth of potassium solubilizing bacteria was determined with flame photometer.The efficiency of K solubilizing by potassium solubilizing bacteria in the culture medium was calculated.The results showed that the standard curves of the three kinds of K series of standard solutions were similar with the R2 values of 0.994 4,0.999 7 and 0.999 8,respectively.After digested by H2O2 solution,concentration of K+ was detected.The efficiency of two strains was 101.1% and 125.1%,significantly higher than that of other groups.The efficiency of potassium solubilizing detected after H2O2 digestion well reflected potassium solubilization of bacteria.
2014,33(2):15-21, DOI: 1000-2421（2014）02-0015-07
Abstract:
Teosinte is the ancestor of maize,and plays an important role in maize domestication process and gene cloning.Solexa RNA-Seq was used to de novo assembly and analyze the transcriptome of teosintes.40.6 GB raw data were produced,including 175 101 250 reads of 76 bp length.After quality control and de novo assembly,58 147 teosinte transcripts with an average length of 1 335 bp were obtained.After bioinformatically comparing,it was found that 94.3% of teosinte transcripts had good matching with B73 cDNAs,and that 84.1% of the transcript had good matching with rice,84.6% with sorghum and 83.9% with brachypodium at protein level.This research will provide a reference for subsequent studies on maize evolution and gene discovery.
Teosinte is the ancestor of maize,and plays an important role in maize domestication process and gene cloning.Solexa RNA-Seq was used to de novo assembly and analyze the transcriptome of teosintes.40.6 GB raw data were produced,including 175 101 250 reads of 76 bp length.After quality control and de novo assembly,58 147 teosinte transcripts with an average length of 1 335 bp were obtained.After bioinformatically comparing,it was found that 94.3% of teosinte transcripts had good matching with B73 cDNAs,and that 84.1% of the transcript had good matching with rice,84.6% with sorghum and 83.9% with brachypodium at protein level.This research will provide a reference for subsequent studies on maize evolution and gene discovery.
2014,33(01):12-17, DOI: 1000-2421（2014）01-0012-06
Abstract:
Seventeen pairs of SSR primers with clear polymorphic bands were screened from 60 pairs of SSR locus covering 17 linkage groups of pear genetic map and amplified with 20 pear cultivars.136 polymorphic bands in total were obtained with 5~11 bands per primer locus (8.0 bands on average).The polymorphism information content (PIC) of the 17 SSR loci ranged from 0.614 to 0.848 with an average of 0.733.All pear cultivars studied could be identified with 38 different combinations of 2 markers each.Bands amplified by each marker were coded based on size of fragment and used as a molecular ID.
Seventeen pairs of SSR primers with clear polymorphic bands were screened from 60 pairs of SSR locus covering 17 linkage groups of pear genetic map and amplified with 20 pear cultivars.136 polymorphic bands in total were obtained with 5~11 bands per primer locus (8.0 bands on average).The polymorphism information content (PIC) of the 17 SSR loci ranged from 0.614 to 0.848 with an average of 0.733.All pear cultivars studied could be identified with 38 different combinations of 2 markers each.Bands amplified by each marker were coded based on size of fragment and used as a molecular ID.
Abstract:
Soil salinity is a major environmental constraint to agricultural productivity.It is a complex network for plant adaptation to salt stress,and it is still a great challenge to improve crop salt tolerance.Mechanisms of SOS signal transduction pathway on Na+ exclusion and compartmentation,the regulation of microRNA and transcription factors involved in salt stress were reviewed.It will provide a fundamental understanding and knowledge for studying salt resistance and breeding salt tolerance in plants.
Soil salinity is a major environmental constraint to agricultural productivity.It is a complex network for plant adaptation to salt stress,and it is still a great challenge to improve crop salt tolerance.Mechanisms of SOS signal transduction pathway on Na+ exclusion and compartmentation,the regulation of microRNA and transcription factors involved in salt stress were reviewed.It will provide a fundamental understanding and knowledge for studying salt resistance and breeding salt tolerance in plants.
2011,30(4):488-493, DOI: 1000-2421（2011）04-0488-06
Abstract:
The morphological variations and discriminant methods of Channa argus (♂)，C.maculata (♀) and their hybrid were studied using traditional morphometrics and the truss network analysis.Body color of C.argus,C.maculata and their hybrid were observed.The results showed significant differences between C.argus and C.maculata from stripe at top of head,side and base of caudal fin,and the hybrid resembled C.maculata from body color.Among eleven meristic characters,the numbers of soft ray of pelvic fin were consistent in these three species,and the numbers of soft ray of pectoral fin deviated from its male parent’s species.The other meristic characters were within the range of its parent’s,the average hybrid index was calculated to be 53.45.The chi-square analysis of meristic characters showed that:there were significant differences(P<0.05) or greater significant differences(P<0.01) between C.argus and C.maculata except the number of pectoral fin rays; greater significant differences(P<0.01) between C.argus and the hybrid except the number of tail fin rays,gill rakers,lateral line scales and scales below lateral line; and significant differences(P<0.05) or greater significant differences(P<0.01) between C.maculata and the hybrid except the number of tail fin rays and gill rakers.Among meristic characters,the number of dorsal fin rays,lateral line scales and scales above lateral line can be used as preliminary indicators to determine the three species.Among ten measurable characters,the average hybrid index was calculated to be 73.90,indicating the measurable character inclined to its male parent’s species (C.argus).Cluster analysis,discriminant analysis and principal component analysis were applied to the measurable character data and the truss network data.The results indicated that the hybrid resembled C.argus from body shape,and there were greater morphological differences among C.argus,C.maculata and their hybrid.Differences between them involved the entire body.Three species could be distinguished by using the 3 formulae established with discriminant analysis which the discrimination accuracy was 100.0%.
The morphological variations and discriminant methods of Channa argus (♂)，C.maculata (♀) and their hybrid were studied using traditional morphometrics and the truss network analysis.Body color of C.argus,C.maculata and their hybrid were observed.The results showed significant differences between C.argus and C.maculata from stripe at top of head,side and base of caudal fin,and the hybrid resembled C.maculata from body color.Among eleven meristic characters,the numbers of soft ray of pelvic fin were consistent in these three species,and the numbers of soft ray of pectoral fin deviated from its male parent’s species.The other meristic characters were within the range of its parent’s,the average hybrid index was calculated to be 53.45.The chi-square analysis of meristic characters showed that:there were significant differences(P<0.05) or greater significant differences(P<0.01) between C.argus and C.maculata except the number of pectoral fin rays; greater significant differences(P<0.01) between C.argus and the hybrid except the number of tail fin rays,gill rakers,lateral line scales and scales below lateral line; and significant differences(P<0.05) or greater significant differences(P<0.01) between C.maculata and the hybrid except the number of tail fin rays and gill rakers.Among meristic characters,the number of dorsal fin rays,lateral line scales and scales above lateral line can be used as preliminary indicators to determine the three species.Among ten measurable characters,the average hybrid index was calculated to be 73.90,indicating the measurable character inclined to its male parent’s species (C.argus).Cluster analysis,discriminant analysis and principal component analysis were applied to the measurable character data and the truss network data.The results indicated that the hybrid resembled C.argus from body shape,and there were greater morphological differences among C.argus,C.maculata and their hybrid.Differences between them involved the entire body.Three species could be distinguished by using the 3 formulae established with discriminant analysis which the discrimination accuracy was 100.0%.
2010,29(3):363-368, DOI: 1000-2421(2010)03-0363-06
Abstract:
The index of heat injury and leaf anatomical structure under the scanning electron microscope of six Primula species were measured to study the responsive mechanism of Primula to the high temperature and to select the heat resistant Primula species.The results showed that Primula forrestii and P.malacoides franch had higher heat-resistance than that of P.obconica,P.veris,P.saxatilis,P.denticulatess.,P.sinodenticulata with lowest heat-resistance.Leaf anatomical structures of Primula associated with heat-resistance included leaf thickness,tightness of mesophyll cell arrangement,the number of open stomata,the number of epidermal hair and powders of leaves.
The index of heat injury and leaf anatomical structure under the scanning electron microscope of six Primula species were measured to study the responsive mechanism of Primula to the high temperature and to select the heat resistant Primula species.The results showed that Primula forrestii and P.malacoides franch had higher heat-resistance than that of P.obconica,P.veris,P.saxatilis,P.denticulatess.,P.sinodenticulata with lowest heat-resistance.Leaf anatomical structures of Primula associated with heat-resistance included leaf thickness,tightness of mesophyll cell arrangement,the number of open stomata,the number of epidermal hair and powders of leaves.
2011,30(5):613-617, DOI: 1000-2421（2011）05-0613-05
Abstract:
Pot experiment was conducted to study the effects of spraying different micronutrients and amino acids into the surface of leaves on yield and quality of Chinese cabbage (Brassica rapa L.).The results showed that methionine,zinc,molybdenum,boron and glycine could increase yield of Chinese cabbage.The treatments of spraying methionine,zinc and molybdenum increased yield of Chinese cabbage significantly.All treatments could reduce the nitrate content of Chinese cabbage with the highest decrease of 35.0% compared with the control.Molybdenum,boron,zinc and methionine might reduce nitrate content of Chinese cabbage significantly.Experiment also indicated that glycine,proline and selenium could both increase the contents of vitamin C,soluble sugar and soluble protein of Chinese cabbage.Therefore,spraying micronutrient or amino acids into the surface of leaves is a good application for increasing yield,reducing nitrate content and improving quality of Chinese cabbage.
Pot experiment was conducted to study the effects of spraying different micronutrients and amino acids into the surface of leaves on yield and quality of Chinese cabbage (Brassica rapa L.).The results showed that methionine,zinc,molybdenum,boron and glycine could increase yield of Chinese cabbage.The treatments of spraying methionine,zinc and molybdenum increased yield of Chinese cabbage significantly.All treatments could reduce the nitrate content of Chinese cabbage with the highest decrease of 35.0% compared with the control.Molybdenum,boron,zinc and methionine might reduce nitrate content of Chinese cabbage significantly.Experiment also indicated that glycine,proline and selenium could both increase the contents of vitamin C,soluble sugar and soluble protein of Chinese cabbage.Therefore,spraying micronutrient or amino acids into the surface of leaves is a good application for increasing yield,reducing nitrate content and improving quality of Chinese cabbage.
2014,33(2):96-102, DOI: 1000-2421（2014）02-0096-07
Abstract:
A 90-day study was conducted to investigate effects of dietary lipid levels on performance,fat deposition,activity and expression of lipoprotein lipase (LPL) in GIFT tilapia (Oreochromis niloticus) juvenile,and to explore the correlation between LPL gene expression and fat deposition.315 GIFT tilapia juveniles(average weight 2.63±0.16 g) were randomly divided into three groups with three replications,and fed with isonitrogenous diets with different lipid levels of 3.7% (low-lipid group),7.7%(middle-lipid group)and 16.6% (high-lipid group) by supplementing with 2%,6% and 15% fish oil as lipid source,respectively.The results showed:(1) the hepatosomatic index (HSI),viscerosomatic index (VSI) and lipid contents in liver and muscle increased with increasing dietary lipid level(P＜0.05),but there was a trends for condition factor (CF) with first increased then decreased (P＞0.05); (2)with increasing dietary lipid levels, the weight gain (WG) first increased, then decreased, and feed conversion ratio (FCR) decreased(P＜0.05); (3)LPL gene was expressed in liver and muscle of GIFT tilapia,while the expression level in liver was significantly higher than that in muscle (P＜0.05); (4) during the 48 h post-refeeding period,liver LPL activity in high-lipid group was significantly higher than that in low-lipid and middle-lipid group at 6 h,but significantly lower than that in low-lipid group at the 12 h,24 h and 48 h.There was a trend in low-lipid and middle-lipid group that liver LPL activity increased first and then decreased; (5) the expression of LPL was significantly higher in high-lipid group than that in low-lipid group (P＜0.05); (6) there were a significant linear positive correlation between HSI,lipid contents in liver and muscle,and liver LPL expression in GIFT tilapia juvenile.The results indicated that LPL expression in GIFT tilapia was in a tissue specific pattern and liver was the main organ for secretion and expression of LPL; high dietary lipid level could inhibit growth of GIFT tilapia juvenile,decrease feed conversion ratio,induce the expression of LPL in liver,and promote fat deposition in liver and muscle; liver LPL expression was involved in fat deposition of GIFT tilapia juvenile.
A 90-day study was conducted to investigate effects of dietary lipid levels on performance,fat deposition,activity and expression of lipoprotein lipase (LPL) in GIFT tilapia (Oreochromis niloticus) juvenile,and to explore the correlation between LPL gene expression and fat deposition.315 GIFT tilapia juveniles(average weight 2.63±0.16 g) were randomly divided into three groups with three replications,and fed with isonitrogenous diets with different lipid levels of 3.7% (low-lipid group),7.7%(middle-lipid group)and 16.6% (high-lipid group) by supplementing with 2%,6% and 15% fish oil as lipid source,respectively.The results showed:(1) the hepatosomatic index (HSI),viscerosomatic index (VSI) and lipid contents in liver and muscle increased with increasing dietary lipid level(P＜0.05),but there was a trends for condition factor (CF) with first increased then decreased (P＞0.05); (2)with increasing dietary lipid levels, the weight gain (WG) first increased, then decreased, and feed conversion ratio (FCR) decreased(P＜0.05); (3)LPL gene was expressed in liver and muscle of GIFT tilapia,while the expression level in liver was significantly higher than that in muscle (P＜0.05); (4) during the 48 h post-refeeding period,liver LPL activity in high-lipid group was significantly higher than that in low-lipid and middle-lipid group at 6 h,but significantly lower than that in low-lipid group at the 12 h,24 h and 48 h.There was a trend in low-lipid and middle-lipid group that liver LPL activity increased first and then decreased; (5) the expression of LPL was significantly higher in high-lipid group than that in low-lipid group (P＜0.05); (6) there were a significant linear positive correlation between HSI,lipid contents in liver and muscle,and liver LPL expression in GIFT tilapia juvenile.The results indicated that LPL expression in GIFT tilapia was in a tissue specific pattern and liver was the main organ for secretion and expression of LPL; high dietary lipid level could inhibit growth of GIFT tilapia juvenile,decrease feed conversion ratio,induce the expression of LPL in liver,and promote fat deposition in liver and muscle; liver LPL expression was involved in fat deposition of GIFT tilapia juvenile.
2010,29(6):798-804, DOI: 1000-2421（2010）06-0798-07
Abstract:
The cracking of fruit skin and the splitting of underlying flesh is a kind of fruit physiological disorder,which downgrades the fruit appearance quality and causes the infection of disease,thereby reducing the commercial value and resulting in serious economic loss.Herein recent studies on fruit cracking were reviewed,mainly focusing on the influence of phenotypic characteristics,genetic factor,physiological characters,mineral nutrients,environmental conditions,plant growth regulators and cultivation practices.The prospect of research was discussed.
The cracking of fruit skin and the splitting of underlying flesh is a kind of fruit physiological disorder,which downgrades the fruit appearance quality and causes the infection of disease,thereby reducing the commercial value and resulting in serious economic loss.Herein recent studies on fruit cracking were reviewed,mainly focusing on the influence of phenotypic characteristics,genetic factor,physiological characters,mineral nutrients,environmental conditions,plant growth regulators and cultivation practices.The prospect of research was discussed.
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