Abstract:Three gene clusters controlling the biosynthesis of the antibiotics actinorhodin (ACT),undecylprodigiosin (RED) and calcium-dependent antibiotic (CDA) were sequentially knockouted by gene replacements from the chromosome of Streptomyces lividans TK24 to derive SBT5.In SBT5,the global regulatory genes afsRScla from Streptomyces clavuligerus was integrated in the place of the cda gene cluster.The act gene cluster from Streptomyces coelicolor was introduced into SBT5 to test its capability of expressing secondary gene cluster.The resulting SBT5 exconjugants overproduced ACT comparing with wild-type strains harboring double copies of the act gene cluster.SBT5 is an efficient host with a clean secondary metabolism background suitable for heterologously expressing and screening secondary metabolic gene clusters.

Abstract:A Bacillus spore cortex-lytic enzyme with the cell wall-binding activity,MbA,was used to develop a novel cell-surface display system of Bacillus thuringiensis.The full-length of mbA gene from B.thuringiensis wild-type strain YBT-9602 genome was PCR-amplified,sequenced and the structural features of its encoding domains were characterized.It showed that the predicted protein MbA was structurally distinguished by an N-terminal domain with peptidoglycan-binding activity and a C-terminal domain with cell wall-hydrolysis activity.By constructing and expressing the fused mbA-gfp,it showed that the heterologous GFP was successfully immobilized onto the surface of B.thuringiensis cells through the immunofluorescence microscopic observation and the assays of pronase accessibility and SDS sensitivity.Furthermore,the recombinant B.thuringiensis cells expressing the MbA-fused chimeric protein with a bacterial β-1,3-1,4-glucanase,were determined the surface-display efficiency using flow cytometry analysis,which showed that a 42.97% recombinant cells exhibited surface-displaying activity.The whole-cell enzymatic activity of the recombinant B.thuringiensis MB220 expressing the mbA-glS fusion gene was detected to be 13.5 U/mL.These results indicated that the MbA protein can be served as a functional carrier protein for developing a novel B.thuringiensis cell-surface display system.

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.

Abstract:The karyotype and fluorescent banding of chromosomes from root tips of Citrus grandis ‘Shatianyou’ seedling were analyzed by CMA/DAPI double staining to investigate the chromosomal structure of ‘Shatianyou’.Results showed that there were six different CMA banding patterns:A type was a chromosome with two terminal and one proximal bands; B was a chromosome with one terminal and one proximal band; C was a chromosome with two terminal bands; D,a chromosome with one terminal band; E,a chromosome with one small terminal band only; F,a chromosome without any bands.CMA banding pattern formula of most seedlings was 2n=18=3A+1B+2C+4D+8F,whereas some were 2n=18=3A+1B+2C+4D+4E+4F,2n=18=3A+1B+2C+4D+8E,2n=18=2A+2B+2C+4D+8F or 2n=18=2A+2B+2C+4D+4E+4F.Compared with CMA bands,DAPI bands were opposite patterns and there were some weak DAPI signals in different degrees.Somatic chromosome synapsis and 2-4 fragile sites were also observed.

Abstract:Using 6 inbred line of broccoli as parents,combining ability and correlation of primary characters about head weight and the glucoraphanin( RAA) concentration were studied by applying Griffing Ⅱ.The results showed that both characters were affected by additive and non additive effects.The head weight was mainly inherited by special combining ability (SCA),were controlled by non-additive genes in a great scale; the glucoraphanin concentration was affected by additive gene greatly were mainly inherited by general combining ability(GCA),it was match the genetic parameters.Narrow heritability of glucoraphanin concentration was bigger than head weight.There were no significant correlations between head weight and RAA content,so both characters would be combined in the same cultivar.In 6 inbred lines,P3 and P2 were ideal parental lines for high yield,and P1 and P4 were ideal parental line for glucoraphanin concentration.Cominations of P4×P6 and P2×P4 had better special combining ability of head weight and RAA concentration,while P2×P4 was the best combination for RAA concentration.

Abstract:A protocol of direct organogenesis from unexpanded leaflets of four Rosa rugosa (Rosa rugosa Thunb.) cultivars was developed.Effects of explants,induction period under dark condition,combinations of plant growth regulators were investigated.The results showed that the highest frequency of adventitious buds induction and plant regeneration were obtained by using a three-stage procedure:initially excised unexpanded leaflets were incubated on half-strength MS (1/2 MS) medium supplemented with 0.05 mg/L NAA and certain concentration TDZ and BA adjusted for each cultivar under the dark condition for 10-15 d and subsequently transferred into light condition for 20 d,adventitious buds excised from the leaves were finally transferred to the MS medium with 0.5 mg/L BA,0.01mg/L NAA in the light for elongation.Bud formation capacity was also significantly affected by the genotype.Among the four cultivars,the highest shoot regeneration response (70.6%) was obtained for ‘Tang White’.For cultivar ‘Puce Dragon’,there were significant effects on adventitious bud induction when incorporating of 1.0 mg/L BA and 0.3 mg/LTDZ on the basic medium.For cultivar ‘Tang White’,‘Puce Dragon’ and ‘Purple Branch’,keeping the cultures under darkness for 10 d promoted shoot induction of leaflets explants,while for ‘Tang Red’,the best results were obtained in darkness for 15 d.Elongated shoots were excised and rooted best on 1/2 MS medium supplemented with 0.5 mg/L IBA.Rooted plantlets,more than 4 roots and longer than 1 cm,were successfully transplanted to soil for acclimatization.

Abstract:The first flowering time,changes of plant height,crown diameter,leaf number and branch number of cut flower,Callistephus chinensis ‘Day Light’,were recorded by separately cultivating it under long days and short days.Results showed that no leaf number difference was found between ‘Day Light’ grown under long days and short days.It tends to have an upright habit with increase in height but decreases in crown diameter and branch number under long days suitable for cut flowers; Flowering of ‘Day Light’ was promoted by short days and was a quantitative short day plant.It was suggested that ‘Day Light’ be cultivated under long days at vegetative stage to develop the high plant type for cut flowers,and then under short days to flower fast.

Abstract:The growth rate and pathogenicity of strains LeekBc-10 and GarlicBc-2 of Botrytis squamosa have been determined in this study. Double stranded RNAs (dsRNAs) in strain LeekBc-10 were cDNA cloned and the resulting cDNA sequences were used to infer proteins and taxonomic status. The results showed that the strain LeekBc-10 was inferior in growth on potato dextrose agar and more vulnerable to infection of garlic leaves, compared to the strain GarlicBc-2. Two dsRNAs, dsRNA-1 and dsRNA-2, were detected in the mycelia of strain LeekBc-10. Sequences of dsRNA-1 and dsRNA-2 are 91.7% and 97.7% identical to the corresponding sequences of dsRNA-1 and dsRNA-2 from Botrytis porri RNA virus 1 (BpRV1). Therefore, the dsRNAs in the strain LeekBc-10 are the genome of a RNA virus, designated as Botrytis squamosa RNA virus 1 (BsRV1). Two open reading frames (ORF), ORF I and ORF II, were predicted on the dsRNA-1 and dsRNA-2 of BsRV1, respectively. They putatively encode two proteins with 1 901 and 1 788 amino acid residues respectively, which were 97.1% and 98.7% similar to the proteins putatively encoded by ORF I and ORF II of BpRV1 respectively. The protein encoded by ORF I of BsRV1 contains the RdRp_4 (RNA-dependent NA polymerase) superfamily domain. The RdRp of BsRV1 has eight conserved motifs for viruses belonging to Totiviridae, Chrysoviridae and Megabirnaviridae and is 19%-23% identical to those encoded by the viruses in these families. This study suggests that BsRV1 and BpRV1 belong to the same virus species, possibly representing a novel virus family.

Abstract:The influence of Spodoptera litura nuclear polyhedrosis virus (SlNPV) on the phenol oxidase activity and haemolymph black of the Spodoptera litura (Fabriciu) larvae was observed by using SlNPV as the immune stimulating factor. The results indicated that the melanization rate in the hemolymph of the host larvae infected with SlNPV at the early 2nd instar began to decrease gradually from day 1 after the virus infection, the ability of the virus in inhibiting the melanization was enhanced with the passage of time after the virus infection and with the increase of host day age; within the 5-day observation time after infection, the percentage of melanization was consistently lower in virus-infection group than non-infected (healthy) group and this difference was significant on days 4 and 5 after infection; in virus infected group, the phenoloxidase activities in the larval body and in the hemolymph of S.litura larvae gradually rose up in the first three days after infection but then dropped down; the phenoloxidase activity in the larval body of S.litura larvae was consistently higher during the first three days but began to be lower from days 4 after infection in the virus-infected group than non-infected group, and this difference was significant on days 2,3 and 5; compared to that in non-infected group, the phenoloxidase activity in the hemolymph of the host larvae in virus infected group began to be enhanced from days 2 after infection but sharply dropped down on days 5 after infection. 

Abstract:High-quality RNA extracted from the twigs of Casuarina equisetifolia is used as the basis for the study of its gene expression. Five RNA extraction methods, i. e. Trizol method, CTAB method, guanidine thiocyanate method, SDS method and Omega RNA isolation kit, were used to extract total RNA from the twigs of C.equisetifolia. The results showed that RNA was unable to be extracted with Trizol and guanidine thiocyanate methods, and the RNA extracted with CTAB method was degraded; only SDS and Omega RNA isolation kit methods could succeessfully to extract RNA from the twigs of C.equisetifolia, however, the RNA quality didn′t meet the requirement of further experiment. SDS method, the most favourable methods in this study, was improved to get better results, and the major improvement was the addition of steps for removing secondary metabolites. Evaluation experiment indicated that RNA with high quality and yield was obtained from the improved SDS method, and could be used for further study of molecular biology such as RT-PCR.

Abstract:Eight terrain factors and five soil conventional nutrients were used as investigating data. Topographic factors were subdivided into five partitions by space grading statistics. Pearson’s correlation analysis was used to explore the typical relation model among five partitions. The similarity analysis between Pearson’s correlation of topographic factors and soil nutrients under distinctive sampling condition was conducted. Results showed that the similarity degree of Pearson’s correlation coefficients between topographic factors and soil nutrients reaches over 99% in different sampling schemes, which is the powerful proof of a characteristic relation model. The relation model of scheme C with 3 661 samples is the most similar to the characteristic relation model, suggesting that it is more rational and the evaluation method in this study is feasible and reasonable.

Abstract:The growth,uptake and accumulation of nutrient of 5 leguminous green manure crops were compared to screen suitable species for citrus orchard at Three Gorges Reservoir under field experiments.The results showed that hairy vetch was on the top of long growth period,followed by smooth vetch and common vetch,which were 23-38 days longer than that of Chinese milk vetch.Smooth vetch,hairy vetch and common vetch grew and covered better before winter,while Chinese milk vetch and white clover grew faster in spring.The yield of fresh grass and the accumulation of N,P and K of smooth vetch were the highest at full flowering stage,closely followed by hairy vetch,common vetch and Chinese milk vetch,the smallest was white clover.All of 5 leguminous green manure crops could normally grow and accomplish their life cycle in citrus orchard at Three Gorges Reservoir.Smooth vetch was the most appropriate for better growth vigor and more nutrients accumulation.

Abstract:In the present study, grass carps were injected intraperitoneally with crude Aeromonas hydrophila lipopolysaccharide (C-LPS),pure Escherichia coli LPS (E-LPS) and phosphate-buffered saline (PBS,as control) at 4 mg/kg,respectively.After 48 h,fish tissues including head kidney,spleen,liver,kidney and intestine in the treated and control group were taken to detect the expression of TNF-α,IL-1β, IL-10 and TLR4 genes by quantitative real time PCR.The results showed that,in head kidney,the expression of TNF-α and IL-1β genes was significantly up-regulated,but the expression of IL-10 was significantly decreased in E-LPS group; the expression of TNF-α and IL-10 genes were significantly up-regulated in C-LPS group,and the TLR4 was significantly decreased in both treated groups.In spleen,the expression of TNF-α,IL-1β and IL-10 genes was not significantly different in E-LPS group from the control,the IL-1β and IL-10 levels were significantly up-regulated in C-LPS group,and the expression of TLR4 was significantly decreased in both treated groups.In kidney,the TNF-α and IL-1β,IL-10 levels were significantly increased in the two treated groups,but the expression of TLR4 gene was not different from the control.In liver,the TNF-α,IL-10 and TLR4 levels were significantly higher in the two treated groups,while the expression of IL-1β was significantly up-regulated in E-LPS group compared to both the control and C-LPS groups.In intestine,the TNF-α and IL-10 genes were significantly induced in the two treated groups and the IL-1β and TLR4 genes were not significantly induced.These results indicated that LPS can induce the expression of the immune related genes of the host,but LPS could not make the up-regulation of the TLR4 gene,which is different from the mammal.

Abstract:Two major isoforms,with an insertion (+KTS) or exclusion (-KTS) in amino acid sequences,resulting from alternative splicing,were cloned from the gonad of rice field eel Monopterus albus by RT-PCR.The length of cDNA sequence of the two WT1 isoforms,WT1 (-KTS) and WT1 (+KTS),were 1 236 bp and 1 245 bp,respectively.The results showed that the amino acid sequences of WT1 (-KTS) and WT1 (+KTS) in M.albus shared 93.2% and 93.0% identity with WT1a in Epinephelus coioides respectively.They also contained highly similar zinc finger domains.The phylogenetic analyses showed that the two isoforms and WT1a of E.coioides were clustered in the same branch.The semi-quantization results revealed that high expression levels of WT1 gene can be found in gonads,kidney,intestine,spleen and heart.The real-time PCR results showed that WT1 gene was expressed at each stage of the gonad development,and the expression increased first and then decreased.

Abstract:In order to investigate the cytogenetic characters of Megalobrama pellegrini,the karyotype and DNA content were studied in the present study.The chromosome number and karyotype were analyzed by a routine method including intraperitoneal injection of PHA and colchicine,cultivation invivo,and slides preparation with air-drying and Giemsa staining.The results showed that M.pellegrini had a chromosome number of 48 (2n=48),with a large and long chromosome pair and no heterosome,and the karyotype was 2n=24m+20sm+4st,NF=92.Erythrocyte nuclear DNA content of M.pellegrini was determined by flow cytometry using the chicken erythrocytes (DNA content is 2.30 pg) as a standard.The DNA content of M.pellegrini is 2.82 pg and the ratio of DNA content between M.pellegrini and chicken is 1.23.

Abstract:Goldfish (Carassius auratus auratus) are the most important ornamental fish and have closely genetic relationship with Carassius auratus.Some goldfish have obvious and beautiful oranda wen.However,how the oranda wen forms and grows is remained unknown.In this study,suppression subtractive hybridization (SSH) strategy was employed to construct a cDNA library that represented genes related to the wen.Wen tissue of 1-year oranda goldfish was treated as the tester and epithelial tissue on the head of 40-days oranda fry was treated as the driver.The housekeeping gene α-tubilin was used to detect the efficiency of the library and the α-tubilin mRNA expression decreased by up to 210-fold in the subtracted libraries compared with the un-subtracted samples,indicating a high subtractive efficiency.The result of nested PCR with adapter specific primers showed that the length of the inserts ranged from 100 bp to 2 000 bp.A total of 93 effective sequence with high otherness were identified by dot-blot screen and sequencing.ESTs in the library were compared,classified and annotated to common data base by bioinformatics analysis,and a set of special genes such as connective related genes and tumor-related genes,which could be involved in wen formation process of oranda goldfish,were identified,indicating that the cDNA library was constructed successfully.

Abstract:The effects of different water temperatures (17,20,23,26 and 29℃) on the embryonic development speed,hatching,survival and fry production rates of silver carp Hypophthalmichthy molitrix were investigated in this study.Meanwhile,the relationships between both growth and deformity rate of the larvae and water temperature were also analyzed.The embryonic development time decreased and development speed accelerated with the increasing water temperature.The hatching,survival and fry production rates were significantly affected by different water temperatures (ANOVA,P<0.01).The survival and fry production rates at 17 and 20℃ were significantly lower than those at 23℃ (P＜0.05),whereas were not significantly different at 26 and 29℃ from those at 23℃ (P＜0.01).At the end of this experiment,the averaged total length of the larvae at 17℃ was significantly lower than that at 23℃,but not different from those at 20,26 and 29℃.Moreover,the deformity of the larvae occurred in all groups and there was no significant correlation between deformity rate and water temperature.The results indicated that the optimal water temperature for early development of silver carp is 23-26℃,the increase of 3-6℃ would not affect the artificial reproduction of the carp,while a sharp decline of 3-6℃ would cause seriously negative influence on the reproduction of the carp.

Abstract:The effects of space size on the weaning success and growth performance of juvenile yellowcheek carp (Elopichthys bambusa) were investigated.Five groups were assigned in different size net cages (length × width × height):0.5 m×0.5 m×0.6 m(S1),1.0 m×1.0 m×0.6 m(S2),1.5 m×1.5 m×0.6 m(S3),2.0 m×2.0 m×0.6 m(S4),3.0 m×3.0 m×0.6 m(S5) and each group contained three replications.The original density of fry (0.64±0.05 g) in each net cage was 500 inds m-3.The weaning success rate (WSR) increased first and then decreased with the increasing of space size,with the highest WSR in S2 and the lowest WSR in S1.The cumulative mortality rate (MR) (30~57 DAH) was highest in S5 and lowest in S3 (P＜0.05).The total cannibalism rate (CR) (30~57 DAH) increased with the increasing of space size.The specific growth rate (SGR) in S1 and coefficient of variation (CV) of body weight in both S2 and S3 were significantly lower than those in other groups (P＜0.05).The optimum size of net cage for the weaning of juvenile yellowcheek carp was 1.5 m×1.5 m×0.6 m based on the comprehensive results of WSR,weaning efficiency and manipulation strength.

Abstract:Soup of silver carp head was cooked by four-stage cooking process using electric sauce-pan.The effects of heating voltage,boiling time,incubating temperature and time on the qualities of soup were investigated.The effects of nutrients,sensory qualities,taste and flavor by different cooking modes were also compared.Nutritional qualities and sensory qualities of soup were significantly influenced by heating voltage,boiling time,incubating temperature and time.The optimal cooking technology optimized by orthogonal experiment was as follows:heating with 180 V and keeping boiling for 20 min,followed by incubating at 75 ℃ for 60 min.The nutrients and sensory qualities of fish head soup by this cooking technology were significantly higher than that of using electric cooking pot.Electronic tongue analyzer and electronic nose analyzer showed that both the tastes and flavors were similar,but SPME-GC-MS analysis revealed that the flavor of soup cooked by electric sauce-pan was rich than that cooked by electric cooking pot,which were identified 69 kinds and 56 kinds of volatile flavor compounds,respectively.

Abstract:The processing technology and brewing condition of mixed loquat flower teabag were studied.The results showed that the fixing technology and drying technology significantly affected the main chemical components and the organoleptic quality of fresh loquat flower.After dried at 40℃ directly with hot air or far-infrared ray,loquat flowers were grinded and sieved to 0.425-1.180 mm,then blended with staple baking green tea at the ratio of 5∶12 and bagged.Chemical components and sensory quality of the mixed teabag were better than that of loquat flower or that of tea.The optimum condition was brewing teabag with 90-100℃ water for 2 min twice.

Abstract:To effectively solve the problems of the transient curing temperature field being out of control and the the malignant phenomenon of curing quality of the food being ruined during in granular food the continuous processing of granular food by using IR (infrared) linear source radiation, the rising temperature model of IR linear source radiation transient curing for granular food was built in this research to analyze its spatial change of irradiance. By means of numerical simulation software, the temperature field form characteristics of transient curing for different diameter granular food with different diameters under different radiation distances were investigated. The results show that the temperature field formation of IR linear source radiation transient curing for granular food depend closely on radiation intensity, particle size, and radiation distance,etc. The heat loss rate on the granular food surface and its change rate of internal energy correspond with the energy balance transient response, and the transient curing temperature field distribution in material reveals a decline along the direction of IR linear source radiation, and in the processing of litchi flesh with 4 mm particle diameter under 50 mm radiation distance, its curing temperature distribution is high and uniform. 

Abstract:In order to research and explore the specific heat capacity of rice straw and establish specific heat capacity prediction model. In this study, 74 samples of rice straws were collected by using differential calorimeter scanner DSC200F3 and the samples were measured by using the specific heat ratio method. The heat capacity and DSC curve of the 74 kinds of rice straws were used as data to do stastic analysis. Gauss function, Polynomial function and Rational function were used to fit the DSC curve of the samples in MATLAB, then establish fitting model of the heat capacity of rice straw and make external authentication for the model. The results show that the specific heat capacity of rice straw is between 0.788 6-6.589 5 J/(mg·K) during the temperature 30-200℃ and the temperature has a great influence on specific heat capacity as well as the geography, variety and growing environment. The variation of rice straw DSC curve is basically the same and the curve shape is similar to the normal distribution curve which has apparent "tail" phenomenon; the heat capacity curve of rice straw can be described by using a Gaussian function which has high prediction accuracy. The correlation coefficient between the measured value and model predictive value of the specific heat capacity is 0.998 6,and the variance and the standard deviation values are 0.648 1 and 0.045 4.

Abstract:A indirect heating carbonization method is used to carbonize the wood chip from trimmed branches, and some technological parameters that influence the carbonization are studied. The parameters are main air inlet, carbonization temperature and carbonization time. The aim of the experiment is to optimize the technological parameters of the carbonization in order to provide technical support to the improvement of the ecological environment and the recycling of the waste in agricultural production. The results show that carbonization yield rate, carbon rate and the charcoals performance are maintained at a high level when the carbonization temperature is controlled at about 500℃, the carbonized time is set at about 12 h, the main air inlet is set at 5 000 mm2,and the chimney height is 2 m.

Abstract:This paper deals with the analysis of the bearing fault mechanism and the extraction method of fault characteristic parameters.A wavelet analysis method was introduced and an improved wavelet packet algorithm was put forward to reduce the frequency aliasing in wavelet analysis after a full consideration of the nonlinear system and the uneven surface vibration signals of rolling bearings.The improved wavelet analysis method largely avoided the frequency aliasing phenomenon and overcame the problem of indistinguishable high and low frequency overlapping in the traditional wavelet packet algorithm. The new analysis method can also separate the noise signal containing the fault signal by using wavelet frequency band.A structural model of the improved wavelet neural network was built by the combination of the advantages of wavelet and neural network.To solve the problem that the convergence speed of traditional BP algorithm is slow and easy to fall into local minima,the algorithm of wavelet neural networks was studied so as to improve it from two aspects: the learning rate and the connection weights.A simulation was then carried out and in the process, N205 type rolling bearing was tested on the test bench and the test data were used in the training network.The results of the network training were obtained by using the vibration signal as input vector for the network.Through the simulation example,it can be found that the improved wavelet neural network can well classify faults,and its convergence speed is obviously faster than of the wavelet neural network under the same condition and the improved BP network, which proves that it can effectively diagnose the faults of rolling bearings. 

Abstract: