Abstract:Six maize ERF genes were isolated and designated asZmERF4, ZmERF26, ZmERF28, ZmERF64, ZmERF89 and ZmERF202,respectively. Results of analyzing gene structure showed that the structures of the maize ZmERF genes isolated were different from those of Arabidopsis AtERF. Results of phylogenetic analysis showed that ZmERFs had a closer relation to OsERFs and a little far relation to AtERFs. Results of expression analysis showed that mRNAs of all six ZmERFs were accumulated firstly and then declined in leaves,whereas the expressions of 4 genes including ZmERF4, ZmERF28,ZmERF64 and ZmERF89 were down-regulated in roots under ET treatment. mRNAs of 6 ERFs were regulated more or less in leaves,whereas expressions of most ZmERFs in roots were not changed significantly under ABA or JA treatment,especially for JA treatment. It is indicated that the ZmERFs might play different roles in hormone signaling pathway of maize leaves and roots.

Abstract:Five BOR gene family members were cloned from seedlings of trifoliate orange (Poncirus trifoliate (L.) Raf.) with RT-PCR and the expression patterns of these genes were analyzed with qRT-PCR（real-time quantitative PCR）under the boron deficiency.The results showed that the open reading frame (ORF) of PtrBOR1，PtrBOR2，PtrBOR3，PtrBOR4 and PtrBOR5 was 2 145,2 133,2 211,1 998 bp and 2 034 bp,respectively.The result of multiple sequence alignment of amino acid showed that PtrBOR1,PtrBOR2 and PtrBOR3 had the conserved endocytosis degradation and polar orientation residues.The phylogenetic tree classified PtrBOR proteins into two subgroups including one subgroup of PtrBOR1,PtrBOR2 and PtrBOR3 proteins and another subgroup of PtrBOR4 and PtrBOR5 proteins.The result of qRT-PCR analyses showed that PtrBOR4 was expressed mainly in leaves,while other PtrBORs were expressed mainly in roots.The expression of PtrBORs varied differently under the boron deficiency.The expression of PtrBOR1,PtrBOR2 and PtrBOR3 was upregulated in roots.The expression of PtrBOR1,PtrBOR2 and PtrBOR4 was upregulated in stems.The expression of PtrBOR1 was upregulated in leaves.The expression of PtrBOR1 and PtrBOR2 was upregulated in two types of tissues at least.

Abstract:Based on MSAP system,we investigated the potential relationship between genomic DNA methylation variation and arris variation of in vitro pitaya (Hylocereus undatus ‘Zihonglong’) shoots.DNA methylation levels and patterns were detected under different subculture duration and cycles using MSAP marker.Also,the relationship between exogenous GA concentration (0,1.5,3.0,4.5,and 6.0 mg/L),endogenous GA content and DNA methylation variation were illustrated.The results showed that no significant correlation was observed between arris and DNA methylation variation.DNA methylation levels of in vitro shoots increased along with the elongation of culture time and subculture cycles.The ratio of semi-methylation in external cytosine were firstly reduced,followed by an increase,which was somewhat consistent with variation of endogous GA contents (406.7,424.3,440.6,398.6 and 409.1 pg/mL).Ratio of full methylation in internal cytosine of CCGG sites demonstrated a negative correlation with the change of ratio in external cytosine,indicating that,exogenous GA might considerably influence the accumulation of endogenous GA.Furthermore,different forms of methylation patterns might be converted to each other,and thus remained the stability of total DNA methylation level.Along with the increase of the exogenous GA concentrations,the mutation rate of DNA methylation decreased (3.6%→4.5%→3.1%→2.7%),which revealed that,DNA methylation variation of pitaya was more sensitive to low GA concentration.

Abstract:In order to investigate the concentrations and potential ecological risks of heavy metals in soils,the total concentrations of Cd,As,Pb,Cr,Cu,Zn and Ni in the topsoil of paddy fields near a Pb-Zn ore deposit located in Hunan Province were analyzed with field sampling and laboratory analyses.The results showed that the soil was seriously polluted by heavy metals.The value of PLI was 2.6 calculated by 25 sampling points,indicating that the extent of contaminated soil is heavy.The potential ecological risk of soil calculated by risk index (RI) revealed that there is a considerable-high ecological risk in study area.The average concentration of heavy metals was in the order of Cd >Pb>As>Cu>Ni>Zn>Cr.Results of correlation analysis and principal component analysis showed that the soil of the studied area was mainly polluted by Cd,Pb,As,Zn.It may be due to the mining activities.

Abstract:The purple soil is typical in the water-level-fluctuating zone of Three Gorges Reservoir.Nitrogen transformation and soil enzyme activities of the soil were investigated at four water depths (0,2,5 and 15 m) in situ experiment.Results showed that the contents of ammonium and nitrate decreased gradually with the increase of water depth after 180 days flooded.Compared with non-flooded (0 m),the contents of ammonium increased significantly at 2 m depth and nitrate decreased significantly at 15 m depth（P＜0.05）.On the whole,soil ammonium and nitrate were significantly affected by water depth （P＜0.05）.The content of soil inorganic nitrogen (ammonium and nitrate) at 15 m depth was 3.96 mg/kg lower than that of non-flooded soil.Activities of enzymes related with soil nitrogen transformation were significantly influenced by water depth（P＜0.05）.With the increase of water depth,the activities of urease and nitrite reductase showed a decreasing tendency.The activities of hydroxylamine reductase and nitrate reductase decreased first and then increased.Activities of all soil enzymes reached the maximum at 2 m depth.Except for urease,activities of other enzymes were higher than that of non-flooded soil.It is indicated that water depth has an important influence on nitrogen transformation and activities of soil enzymes.

Abstract:Genome sequencing and bioinformatics analyses indicated that Streptomyces thioluteus has great potential to produce a variety of bioactive natural products and possesses complex regulatory mechanisms of secondary metabolites. In order to investigate the biosynthetic pathways of putative secondary metabolites and regulation mechanisms in this strain, a genomic expression library of S. thioluteus was constructed by using an integrative Streptomyces plasmid pJTU2554 as the vector. Nine heterologous expression mutant strains with antibacterial activities were obtained by bioassay screening of the expression library in the heterologous host of Streptomyces lividans ZX1. Positive clones carrying the putative polyketide synthase (PKS) and noribosomal peptide synthetase (NRPS) genes were screened from the library by PCR. Results of TLC and HPLC-MS analyses showed that heterolgous expression of 6 positive cosmids containing the aureothin biosynthetic gene cluster in S. lividans ZX1 resulted in the production of the polyketide antibiotic, aureothin. It is indicated that heterologous expression and screening of the library was successful in S. thioluteus.

Abstract:To further clarify the biosynthesis and regulation pathways of avermectins and to increase its production,a bacterial artificial chromosome (BAC) library was constructed using the BamHⅠ-digested genomic DNA of Streptomyces avermitilis. The Streptomyces avermitilis BAC library was consisted of 2 304 clones with an average insert size of 101 kb,empty clone rate of about 9%,and 25.9-fold coverage of the whole genome. The DNA phosphorothioation of the Streptomyces avermitilis genome made it very difficult to construct a BAC library. The successful construction of this BAC library will provide a reference for constructing BAC libraries of other microorganisms, especially those with DNA phosphorothioation.

Abstract:Based on the bioinformatics prediction of small non-coding RNA(sRNA), SraG sRNA was predicted and confirmed by Northern blotting. The full-lengh SraG was obtained with RACE and high-throughput sequencing of transcriptome. The secondary structure and target genes of SraG were predicted with RNAfold and TargetRNA software,respectively. To confirm the function of the SraG gene in symbiotic nitrogen fixation, a disruptant strain of SraG was constructed and named M. huakuii SraGmut. The pot experiments of plant nodulation were conducted to examine the nitrogen fixation ability of the disruptant strain. The nitrogenase activity of A. sinicus L. inoculated M. huakuii SraGmut was only 40% of that of inoculated M. huakuii 7653R, indicating that SraG as a RNA affected the symbiotic nitrogen ability of the rhizobium tested. It provides a solid foundation for studying the functional mechanism of sRNA during symbiotic nitrogen fixation of rhizobium in the future.

Abstract:The biocontrol effect of endophytic fungi Chaetomium globosum against rapeseed clubroot was studied in laboratory.Results showed that after irrigating spores suspension of C. globosum around rapeseed root,the activities of peroxidase,polyphenol oxidase and phenylalanine ammonia lyase were all obviously increased.When the spore suspension of C. globosum was inoculated by irrigation rapeseed rhizosphere soil,the disease incidence and disease index of rapeseed clubroot were significantly decreased.The control efficiency was 76.88%.The active compounds were isolated and purified from C. globosum culture by polarity gradient extraction,thin layer chromatography and HPLC. The active substances were identified as C16 sphingosine and phytosphingosine via LC-MS.The sphingosine obviously inhibited the germination of Plasmodiophora brassicae resting spores.MIC value of sphingosine was lower than 0.1 μg/mL.The antagonistic mechanisms of C. globosum to P. brassicae were confirmed as induced systemic resistance and secondary metabolites.

Abstract:In order to apply the technology of in vitro lamb embryo development to production,we studied the possible effects of factors such as dose of FSH,individual rams,oocyte obtain methods on in vitro embryo development and the conception efficiency after transplantation. The results showed that injection dose of FSH 240 IU or 420 IU per donor had no effect on the number of obtained oocytes,the number of embryos,and in vitro fertilization and cleavage rate (P＞0.05). Ram had significant effects on in vitro oocyte fertilization efficiency (P< 0.05),but did not affect the pregnancy rate of embryo transplantation (P＞0.05). When compare oocyte harvesting method of ovum pick up (OPU) with slaughterhouse,there was no effect on the recovery of oocyte (12.24 vs. 13.84,P>0.05). However,the average number of embryos obtained by OPU was significantly lower than that obtained by slaughterhouse (7.50 vs 11.17,P<0.05),and the cleavage rate was extremely significantly lower than the latter (60.92% vs 81.75%,P<0.01). All of the above tests had no effect on the pregnancy rate (P＞0.05). Using 240 IU donor FSH and selecting the fertilization efficiency ram,can significantly improve the in vitro embryo production. The in vitro developmental ability of the oocyte harvested by the slaughterhouse was higher than that by OPU.

Abstract:A computer program was developed for parentage identification and paternity inference based on the single nucleotide polymorphisms (SNPs) of parents and offspring from known livestock population.Furthermore,the approach was tested with a simulated population with 600 000 SNP markers.Results showed that at least 100 SNPs are needed for correct parentage identification and a minimum of 300 SNPs for correct paternity inference.However,using markers with low average minor allele frequency can decrease the accuracy of paternity inference.The time for parentage identification of 1 000 pedigrees with 10% errors genotyped with 50 000 SNPs was 332.87 s,which showed linearly relationship with the number of markers and individuals.In this study,a computer program was developed for parentage identification and paternity inference according to Mendel’s law and testified with markers from known genotypes of parents and their offspring.The program runs fast and simply with higher accuracy,and hence can be implemented potentially in relevant studies of genomics in livestock population.

Abstract:We studied the changes in the serum COR,GLU,LDH,TC,AST,ALT and CREA,as well as the respiratory rate of grass carp at 0 h,0.5 h,1 h,6 h and 24 h after the grass carp passed the jet fish pump under 4 operating conditions.In comparison to the fish who didn’t pass the jet fish pump,fish who passed the pump under the 4 operating conditions showed an increase in the serum COR,CREA,LDH,AST and ALT as well as the respiratory rate at the first recovery period and then those values decreased to control values gradually,while the serum GLU showed a decline after an initial increase.There was no significant difference in the serum TC in the present study.In addition,the descaling was observed in grass carp under the 4 operating conditions.When fish passed the jet fish pump under the 4 operation conditions,there were no rupture of swimming bladder and damage of viscera.Among the 4 operating conditions,the third operating condition showed less influence on grass carp than the other operating conditions.

Abstract:Misgurnus mohoity (H),Misgurnus bipartitus (N),Misgurnus anguillicaudarus (diploid,B; tetraploid,T) and Paramisgurnus dabryanus (P) were used here to produce 11 kinds of selfing/hybrid offsprings,namely H×H (female×male,HH),N×N (NN),P×P (PP),B×B (BB),P×B (PB),N×H (NH),N×P (NP),P×H (PH),B×P(BP),T×P (TP),and P×T (PT).The culture experiment lasted for 270 d.Total lengths and body weights of the 11 different offsprings were measured at 60d,90d,120d,150d,and 270d,meanwhile the malonaldehyde (MDA) contents were measured at 60 d,90 d,and 120 d.Results obtained here showed that NP kept good growth performance in the entire experimental period.Growth tendencies of PB and PP were poor during the early period from 60d to 90 d,but they began to rise and became good as time went on.In addition,there was no significant difference in growth traits between PB and PP (P>0.05).The body weight of PB at 270 d obviously outweighed other offsprings (P<0.05).The ratios of NP in the 20% of the maximum total length and body weight at 60 d and 90 d exceeded other offsprings.The ratios of TP in the 20% of the maximum and minimum total length and body weight at 270 d were relatively high,while always high for PB in all the sampling times.Both NP and PP with good growth potential had relatively low MDA contents.MDA content of PB rose at 90 d and then stayed high.In conclusion,NP and PP had advantages in growth and immune performance,and PB presented breeding potential in growth traits.

Abstract:In order to determine the optimal requirement of dietary lipid for butterfish (Scatophagus argus),5 isonitrogenous diets containing 3%,6%,9%,12%,15% lipid levels (F1-F5) were prepared with fish oil as lipid source,to feed the butterfish juveniles (average body weight 4.3 g) for 8 weeks in the floating cages in the sea,and the growth performance,immunity and antioxidant indexes and endogenous digestive enzyme activities of the fish were determined.The results showed that both the weight gain rate (WGR) and specific growth rate (SGR) reached the maximum values in F3 group with 9% dietary lipid level but showed no significant difference with F4 and F5 groups.Moreover,the maximum value of the protein efficiency rate (PER) was observed in F4 group with 12% dietary lipid level,and there was no significant difference among the F2-F5 groups with 6%-15% dietary lipid levels.However,the feed conversion ratio (FCR) displayed an opposite tendency,with the minimum value was observed in F3 group with 9% dietary lipid level and no significant difference was observed among the F2-F5 groups.The hepatosomatic index (HSI) increased with the increment of the dietary lipid levels and was significantly higher in F5 group with 15% dietary lipid level than those in F1 and F2 groups.The dietary lipid levels also significantly affected the contents of crude lipid,protein,ash and moisture of fish body.When the dietary lipid level was 9%,the fish exhibited higher lipase activities in the stomach and intestine and better immunity and antioxidant indexes in the intestine and liver than the other groups.The regression analysis of dietary lipid levels with WGR or FCR was conducted separately by the curvilinear method and the results suggested that the optimal dietary lipid level is 8.6%-11.0% for juvenile butterfish.

Abstract:The expressed outer membrane protein (Omp,about 52 ku) of Edwardsiella tarda was purified after the recombinant expression vector was constructed,transferred into E.coli BL21 and induced.A total of 100 healthy Japanese eels (Anguilla japonica) was divided into 2 groups and intraperitoneally injected (i.p) with bovine serum albumin (BSA,0.5 mg/mL) and the outer membrane protein (Omp,0.5 mg/mL),respectively.On 7,14 and 28 d post-vaccination,the blood,skin mucus,liver and kidney of eels were collected to evaluate the lysozyme and complement activities,stimulation index and specific antibody titers.The complement activities in the Omp group were extremely significantly（P＜0.01） higher than that of the BSA group on 7 d.The specific antibody titers in the Omp group were significantly (P＜0.05 or P＜0.01） higher than that of the BSA group on 14 d and 28 d.The lysozyme activities and stimulation indexes showed no significant difference (P＞0.05) between two groups.The relative percent survival (RPS) of Omp were 71.4%,50.0% and 12.5% respectively after challenged by E. tarda,A. hydrophila or V. vulnificus.These results suggested that the recombinant expressed Omp could significantly improve the immune function and resistance of A. japonica against E. tarda.It also had significant cross protection against A. hydrophila,but had weak cross protection against V. vulnificus.

Abstract:Under different pretreatment methods of heat,smashing and their combination,the collagen peptide of crass carp scale was obtained after the processes of enzymatic hydrolysis,centrifugalization and freeze drying.The yield and properties of specimens were compared and analyzed.Results showed that the average values of the nitrogen recovery,degree of hydrolysis,amino-N production and anti-oxidant activity in vitro were significantly different between different pretreatment groups (P<0.05).The relative molecular weight and distribution did not vary significantly with pretreatment methods.Considering the yield and properties of end-products,the ideal pretreatment method is heat and smashing for collagen peptide extracted from crass carp scale.

Abstract:Effects of pretreatments including ice,freezing,heating at 100 ℃,and heating at 120 ℃ on the physical properties of fish bone pastes made from silver carp using wet milling were studied.Results showed that fish bone particles in the paste subjected to 120 ℃ heating before milling was the smallest with an average size of 164.11 μm.The increasing order of average particle size was sample subjected to freezing (317.40 μm),heating at 100 ℃ (343.47 μm) and ice (522.61 μm).Specific surface area of the fish bone particles in the paste subjected to 120 ℃ was significantly larger (P<0.05) than that of other three groups.Result of SEM showed that fish bone particles in the paste subjected to freezing was short-rod like with a smooth surface.Fish bone particles in the paste subjected to 120 ℃ was nearly spherical with a coarse surface.Compared with the samples added with ice and/or subjected to freezing,b,L*,water holding capacity,emulsion reactive index and emulsion stability of the paste subjected to 120 ℃ heating were significantly higher (P<0.05),while its viscosity was lower (P<0.05).

Abstract:A rapeseed harvester combined stripping table with cutting table was designed based on the biological characteristics of rapeseed.By modeling the kinematic buildings of stripping drum and reel slat,the parameters of structure and kinematic parameters of reel slat,stripping drum,cutting unit and cover casing were determined.Parameter combinations were optimized and motion simulation analyses of stripping drum were made.The results showed that the ground projection of stripping fingers covered the whole crops when the distance of fingers was 70 mm and their axial obliquity was less than 82°.The rotation rates of reel slat and stripping drum were 20-30 r/min and 220-270 r/min,respectively.The horizontal distance of them should be wider than 374 mm.The results of simulation and field trials showed that stripping cutting table realized stripping,throwing,cutting and reeling straw.It will provide a new method of designing the structure of rapeseed oil combined harvester.

Abstract:In order to reduce mechanical injury during harvesting the lotus roots,Elian No.5 with moisture content of lotus rhizome ranging from 82.78%-86.69% was used.Compression test for lotus rhizome pulp,segments and the whole lotus,bending and stretch test for joints of lotus roots was conducted with the TMS-protexture analyzer and the RGM-3005 accurate micro-controlled electronic universal testing machine.The results showed that the compressive strength of lotus rhizome pulp was 0.908-1.750 MPa.The elastic modulus was 0.451-2.529 MPa.The values of both compressive strength and elastic modulu of pulp closed to edge were bigger than that of core along the same direction.The value of elastic modulu along axial was bigger than that of radial in the same segments,indicating that lotus belongs to anisotropic materials.The average value of joints’ bending strength from the first to the second was 1.337,1.227,and 1.153 MPa,respectively.The average value of joints’ stretch strength from the first to the second was 0.546,0.560,and 0.551 MPa,respectively.There was a positive correlation between bending force and diameter,stretch force and diameter.It will provide theoretical basis for studying water erosion parameters of lotus root with digging machine.

Abstract:The sizes and the uniform performances of peanut seeds are the basis of seed cleaning and grading,and the core element of breeding peanut.Three axis dimensions,the average diameter and weight per 100 seeds were selected as indicators.The differences,distribution and interrelation of the three axis dimensions of the seeds,the uniform performance and the relationship between seed sizes and the weights were analyzed with statistics.The results showed that three axis dimensions obeyed the normal distribution with significant differences among different varieties of peanuts.There were linear correlations between three axis dimensions.Differences between seeds of peanut varieties were homogeneity.The geometric mean diameter of peanut seeds,arithmetic mean diameter and the trends of weight changes were basically same.The sizes and the uniform performances were significantly different among peanuts varieties.Many factors should be comprehensively taken into account on cleaning and grading of peanuts seed.