Special Issue

Plant protection
Crop diseases and insect pests are one of the major agricultural disasters in China, which have the characteristics of many kinds, great influence and  outbreaks  frequently.This special topic selects papers related to plant protection published in Acta Agriculurae Boreali-Sinica , involving the disease control on rice planthopper, powdery mildew, corn borer, cotton bollworm, wheat rust, cotton aphid, rice sheath blight, rice blast, etc.Click on the relevant paper to open the web page and download the full text. In order to quote and share for readers, each article contains a complete citation format in Chinese and English (including international DOI number) and a proprietary  QR code. Long press the  QR code of the article to open the web page of the article and realize mobile sharing at the same time. Thank you for downloading, quoting, forwarding and sharing.
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  • XIAO Shikui, LI Fang, ZHANG Wenting, LÜ Shufang, SHI Guoan, WU Jiang, FAN Bingyou
    Abstract (75) PDF (22) RichHTML (8)

    In order to explore the function of ACS gene in herbaceous peony,a full-length cDNA sequence of PlACS cDNA in Paeonia lactiflora was obtained,RACE technique and bioinformatic methods were used to analyze the protein sequence which it encoded.The CDS of PlACS was subcloned,the prokaryotic expression vector of PlACS was constructed based on pET32a vector,and then the highly efficient prokaryotic expression system was established.The results showed that the total length of PlACS cDNA(GenBank accession JX512359)was 1 752 bp,which encoded 492 amino acids.Seven conserved regions and active sites K278 were detected in PlACS protein.Phylogenetic tree analysis showed that PlACS was highest homological with ACS of P.suffruticosa.PlACS protein was determined structurally to be 40.04% α-helix,16.26% β-extended strand,6.91% β-turn and 36.79% random coil.Protein 3D structure homology modeling predicted that PlACS existed as homodimers.The optimal expression condition of PlACS protein was that when the cell density of genetic engineering strain A600 reached 0.2,IPTG with a final concentration of 0.1 mmol/L was added,and the recombinant protein was expressed for two hours at 37 ℃.It was of great significance to acquire PlACS recombinant protein with biological activity by denaturation & renaturation and identify its enzymatic activity in vitro.

  • HAN Xiaoyu, LI Qinglun, JIANG Xinglin, WANG He, YANG Lingling, SHI Yajuan, LI Honglian, CHEN Linlin, YANG Xue, SHI Yan
    Abstract (33) PDF (8) RichHTML (1)

    Wheat yellow dwarf disease,caused by Barley yellow dwarf viruses(BYDVs),is an important viral disease in wheat production.BYDV GAV has become the main pathogen causing wheat yellow dwarf disease.Till now the studies on the function of BYDV GAV encoded proteins P1,P2 and CP are lacking.We focued on the function of P1,P2 and CP,which could lay the foundation for the pathogenic mechanism of BYDV GAV.Phylogenetic analysis of BYDV GAV encoded P1,P2 and CP was conducted using Mega 7.0.We constructed the YFP expression vector of P1,P2 and CP,and then transformed them into GV3101 and infiltrated the leaves of Nicotiana benthamiana.The subcellular localization of P1,P2 and CP was observed using confocal laser scanning microscopy(CLSM).We constructed the biomolecular fluorescence complementation assay(BiFC)vectors of five coding proteins,and then transformed them into GV3101 and infiltrated the leaves of Nicotiana benthamiana.CLSM was used to observe the interaction of P1,P2 and CP and other viral proteins in vivo.Furthermore,we constructed the Potato virus X(PVX) expression vectors of P1,P2 and CP,transformed them into GV3101 and infiltrated the leaves of Nicotiana benthamiana.At 5 days post inoculation(dpi)the symptom formation of PVX infection was observed.The systemic leaves were collected for detection of viral accumulation to determine the effects of the pathogenicity of P1,P2 and CP.Results showed that BYDV GAV was most closely related to BYDV PAV at the nucleotide level.Subcellular localization of P1,P2 and CP was cytoplasm and nuclear.P1 interacted with itself in vivo using BiFC.In the pathogenicity assay,the systemic leaves of PVXCP infection showed chlorosis at 5 dpi,and PVX accumulation was detected,while PVX,PVXP1 and PVXP2 infection showed no symptoms in systemic leaves and PVX accumulation was undetectable,which was detected at 10 dpi,indicating that CP promoted the formation of PVX symptoms.In brief,P1 possibly involves in viral infection via self-interaction in vivo,and CP can promote viral infection.

  • WANG Ya, WANG Yuetao, SHEN Guanwang, WANG Fuhua, WANG Shengxuan, BAI Tao, YIN Haiqing
    Abstract (41) PDF (33) RichHTML (0)

    In order to improve the blast resistance of Shuijing 3,an excellent food-flavor rice variety,CRISPR/Cas9 gene editing technology combined with gene chip technology were used to pyramid the R gene Pigm and the non-R gene bsr-d1 into Shuijing 3.Firstly,Bsr-d1 was selected as the target gene to construct a recombinant expression vector using the CRISPR/Cas9 gene editing system,and transformed into the excellent food-flavor rice Shuijing 3 by Agrobacterium-mediated method.The homozygous bsr-d1 mutant lines without T-DNA elements,including five mutation types as T insertion,G insertion,GA deletion,CGCA deletion and CGCAGA deletion,were screened out.The japonica line Jinyu 1 containing a broad-spectrum blast resistance gene Pigm was used as the gene donor parent to cross with the homozygous bsr-d1 mutant lines without transgenic components.The Pigm gene was introduced into bsr-d1 mutant lines by cross,backcross and self-cross combing molecular breeding chip to simultaneously perform Pigm gene and background-assisted selection.The improved lines SJ3-G1,SJ3-G2,SJ3-G3,SJ3-G4,SJ3-G5,which were homozygous for the disease resistance genes(carrying both bsr-d1 and Pigm genes)and whose background recovery rates were all above 96%,were finally obtained.The improved strains of Shuijing 3 displayed enhanced leaf blast resistance compared with the wild type in inoculated identification test using Magnaporthe grisea strain GUY11.After inoculation with M.oryzae,the POD activities in the improved strains of Shuijing 3 were significantly lower than that of the wild-type control,while the H2O2 contents were significantly higher than that of the wild-type control.The improved Shuijing 3 lines with blast resistance carrying both bsr-d1 and Pigm genes are obtained by CRISPR/Cas9 gene editing technology combined with gene chip technology.

  • QU Dong, YAN Fei, LIU Xinrui, KANG Xue, ZENG Haitao, ZHANG Yu
    Abstract (52) PDF (10) RichHTML (5)

    In order to explore the mechanism of AcWRKY70 transcription factor in response to kiwifruit canker stress in different resistant varieties,AcWRKY70 gene was cloned from the leaf cDNA of resistant variety Xuxiang and highly susceptible variety Hongyang kiwifruit.The sequence structure characteristics of Hongyang AcWRKY70 gene,subcellular localization and evolutionary relationship of Hongyang AcWRKY70 protein were analyzed. The expression patterns of AcWRKY70 gene,including the tissue expression and different expression in resistant kiwifruit varietie and susceptible variety under Pseudomonas syringae pv. Actinidiae(Psa),salicylic acid(SA)and methyl jasmonate(MeJA)treatment were analyzed by RT-qPCR. Results showed that the full length of the Hongyang AcWRKY70 gene was 906 bp(GenBank accession number was MW881147). AcWRKY70 gene contained 885 bp of open reading frame(ORF)and encoded 294 amino acids. AcWRKY70 protein had typical WRKYGQK domain and the zinc finger structure was C2-HC. It belonged to class Ⅲ group of WRKY family and islocated in the nucleus. Phylogenetic tree analysis showed that it had the closest genetic relationship with tea plant. Both Hongyang and Xuxiang AcWRKY70 genes had the highest expression level in leaves. Under Psa treatment, the highest expression of AcWRKY70 gene reached at 12 h in Xuxiang, the expression of Hongyang reached the maximum at 48 h.Under the co-treatment of salicylic acid and Psa(SA+Psa),Methyl jasmonate and Psa(MeJA+Psa),the highest expression of AcWRKY70 gene reached at 12 h in Xuxiang. Under SA+Psa and MeJA+Psa treatment,the expression of Hongyang reached the maximum at 72,24 h,respectively. AcWRKY70 gene played a certain role in resistance stress of kiwifruit,and the response mechanism to pathogens in different resistance kiwifruit varieties may vary considerably.

  • SU Fang, HAN Diangang, YE Lingling, ZHANG Chong, YIN Shanglian, LUO Qianmin, DONG Xianlan, LI Yaoyao, LI Lingfeng, AI Jun, XIN Jige
    Abstract (50) PDF (9) RichHTML (4)

    In order to obtain COVID-19 nucleocapsid protein with similar function and activity to natural protein and apply it to practical detection. Firstly,according to Bac-to-bac insect expression system and synthetic COVID-19 nucleocapsid protein(N protein)sequence,BamH Ⅰ and Xba Ⅰ on pFastBacTMHTB vector were added to upstream and downstream primers respectively. The N gene was amplified by PCR technology,and T-Vector pMD19(simple)vector and pFastBacTMHTB vector were connected successively and recombinant plasmids pMD19-T(simple)-COV19-N and pFastBacTMHTB-COV19-N,and finally construct recombinant bacmid DH10Bac-pFastBacTMHTB-COV19-N in DH10Bac cells was expressed in insect cell Sf9. The recombinant protein was obtained and analyzed by SDS-PAGE and WB. The recombinant plasmid pMD19-T(simple)-COV19-N was identified by PCR and double enzyme digestion. The recombinant bacmid DH10Bac-pFastBacTMHTB-COV19-N was constructed in DH10Bac cells was identified by PCR and the expected two bands were 2 430,3 690 bp,respectively,which proved that the recombinant bacmid was successfully obtained. The recombinant bacmid was transfected into Sf9 insect cells. At the same time,the recombinant GFP protein control group was established. After 120 h of transfection,the recombinant N protein and recombinant GFP protein were collected and samples were prepared;SDS-PAGE and WB analysis were carried out respectively. HRP-His labeled antibody was used to verify that the transfection was successful,and both recombinant N protein and recombinant GFP protein were successfully expressed in Sf9 cells. The experimental results were consistent with the expectation,and the size of recombinant N protein band was about 46 ku. The eukaryotic expression vector of respiratory coronavirus N gene was successfully constructed and successfully expressed in insect cells,which provides an experimental basis for the establishment of ELISA detection methods and other related research.

  • LIU Jiayue, JIA Lixia, WANG Miaomiao, SUN Donghui, SUN Hehe, HAO Zhimin, LI Zhiyong
    Abstract (2150) PDF (32) RichHTML (2)

    In order to reveal the diversity characteristics of endophytes in different species and different organs,the correlation between endophyte community structure and host species and organ types was preliminarily clarified.The stems,leaves and leaf sheaths,which were respectively collected from the plants of the foxtail millet blast-susceptible varieties Shawan millet and Jigu 22 and the foxtail millet blast resistant varieties Xiaoqinggu and Shiliuzi,were used to carry out the endophytic diversity by high-throughput sequencing based on the 16S rDNA V3—V4 region.There were certain differences in endophyte species composition between susceptible and resistant varieties.In all tested samples,the dominant groups at the phylum level were Proteobacteria and Actinobacteriota.Bacteroidota,Chloroflexi,Myxococcota,Firmicutes followed.Alpha diversity analysis showed that the susceptible varieties(Shawan millet,Jigu 22)had higher abundance of endophyte in leaves.PCoA analysis revealed that the organ type had a greater impact on the endophyte community structure than the variety.Species composition analysis showed that the susceptible varieties Shawan millet and Jigu 22 contained endophytic flora that were significantly different from those of Xiaoqinggu and pomegranate(resistant to foxtail millet blast).The susceptible varieties(Shawan millet,Jigu 22)contained Entotheonellaeota phylum in leaves,while resistant varieties had Hydrogenedentes phylum in leaf sheaths.It clarified that the diversity and community structure of endophytes in different organs and millet varieties susceptible and resistant to foxtail millet blast were different,and organ types had a greater impact on the community structure of endophytes than varieties.

  • ZHANG Dongmei, FENG Yayan, XIU Zhijun, YANG Chunfang, DU Meie, LI Dezhou, ZHANG Xiaoyu
    Abstract (38) PDF (20) RichHTML (3)

    In order to study the molecular mechanism of sodium silicate enhancing risistance of potato to Rhizoctonia solani,a gene StWRKY11 with high expression level in potato transcriptome induced by sodium silicate was cloned and its bioinformatics was analysed.Total RNA was extracted from potato,amplified by RT-PCR and cloned.Through bioinformatics related software,the structure prediction and prediction analysis were carried out.The results showed that StWRKY11 gene with a open reading frame of 1 005 bp was cloned from potato Atlantic,encoding 334 amino acids.The molecular formula of the expressed protein was C3013H5023N1005O1260S199,the molecular weight was 81.867 94 ku,the theoretical isoelectric point(pI)was 5.09,and the total number of atoms was 10 500.The expressed protein contained a typical WRKYGQK conserved domain,and the zinc finger structure was CX5CX23HXH,belonging to the second Ⅱ d subfamily.The secondary structural elements were α-helix,extended chain,β-folding and random coiling,among which the proportion of random curl was the highest,up to 61.68%.There were 29 phosphorylation sites in total,which might be located in the nucleus.There were cis-regulatory elements upstream of the promoter that might related to resistance stress response and cis-regulatory elements related to growth and development and hormone response.The gene was closely related to potato StWRKY5 gene,and the amino acid homology of the coding protein reached 95%.

  • ZHAO Siqi, QUBI Wuhe, LUO Ting, YU Xuejie, KE Yongpei, GOU Qixian, SHI Haichun
    Abstract (37) PDF (30) RichHTML (26)

    To investigate the physiological and biochemical responses of maize to gray spot stress.Using the natural inoculation method in the field,two inbred lines K365(resistant)and K169(susceptible)and two hybrids Zhenghong 431(resistant)and Zhenghong 532(susceptible)were used as test materials.To study the effects of gray spot disease on leaf photosynthesis,reactive oxygen species content,antioxidant enzyme activity and endogenous hormone content of different resistant maize inbred lines and hybrids.Gray leaf spot stress led to the decrease of net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr) of maize leaves, except for Ci, the three photosynthetic indexes of resistant materials did not decrease significantly, specifically, Pn, Gs and Tr of K365 decreased by 24.41%,25.00% and 4.20%, respectively. The Pn, Gs and Tr of positive Zhenghong 431 decreased by 11.53%, 21.43% and 0.06%, respectively, while the three photosynthetic indexes of susceptible material decreased significantly, specifically, Pn, Gs and Tr of K169 decreased 59.32%, 95.28% and 80.18%, respectively. The Pn, Gs and Tr of Zhenghong 532 decreased by 85.39%, 69.60% and 56.77%, respectively;at the same time, the content of hydrogen peroxide (H2O2), peroxidase (POD) activity, superoxide dismutase (SOD) activity, catalase (CAT) activity, salicylic acid (SA) content, and jasmonic acid (JA) in maize leaves were increased under leaf gray spot stress, and the resistant materials could stimulate higher POD,SOD and CAT activities,maintaining a relatively stable H2O2 content,more reasonable regulation of SA and JA content,could maintain the balance of endogenous hormones.Resistant material may through rational accumulation of SA,JA signaling molecules to regulate antioxidant system,late in the disease still maintain a high level of defense enzymes in the body to more effectively remove excess H2O2,at the same time,adjust the blade endogenous hormone balance to make it adapt to the effects of resistant,thus to enhance maize disease resistance.

  • JIA Jianping, LI Jinhong, YU Jingwen, YU Xiyue, PENG Deliang, LI Huixia, HUANG Wenkun
    Abstract (33) PDF (10) RichHTML (24)

    In order to explore the control effect of nitrogen fertilizer on soybean cyst nematode disease,pot experiment and field experiment were carried out to analyze the effect of nitrogen fertilizer on the egg hatching,nematode development of soybean cyst nematode and the yield of soybean. Four nitrogen application levels were set as 0.016,0.032,0.048,0.064 g/kg soil,respectively,to analyze the effect of soil eluviating solution and root exudate solution on egg hatching. In the field experiment,four nitrogen application levels were set as 22.50,56.25,67.50,78.75 kg/ha,respectively,to analyze the effect of nitrogen fertilizer on the development of nematode. Treatment without nitrogen fertilizer was used as a blank control in all experiments. The results of pot experiment showed that both soil eluviating solution and root exudate solution could significantly improve egg hatching inhibition rate of H. glycines after nitrogen fertilizer application. The soil eluviating solution of 0.032,0.064 g/kg soil had the best inhibition effect on H. glycines egg hatching,reaching at 34.21% and 29.31%,respectively,the root exudate solution of 0.064 g/kg soil had the best inhibition effect on egg hatching of H. glycines,reaching 55.09%. The field experiment showed that proper application of nitrogen fertilizer could significantly decrease cyst number but increase soybean yield. Treatment with 56.25 kg/ha nitrogen fertilizer had the best control effect on nematodes and the highest yield of soybean,with cyst number decreased by 25.29% and the yield of soybean increased by 14.75%. However,the number of nematode in the control increased by 30.77%. Therefore,application of nitrogen fertilizer is an economical and safe control method to improve the yield and quality of soybean.

  • FENG Liting, ZHANG Jianfeng, CHI Shengqi
    Abstract (28) PDF (12) RichHTML (20)

    A multiplex RT-PCR detection system was established and studied to target four sweet potato RNA viruses,Sweet potato feathery mottle virus (SPFMV),Sweet potato chlorotic stunt virus (SPCSV), Sweet potato virus G (SPVG)and Sweet potato virus C (SPVC),which caused serious damage in sweet potato production. Firstly,the specific primers for four viruses were designed by Premier 5.0 software and synthesized according to the conserved sequences of coat protein(CP)gene of these viruses from GenBank. The cDNA synthesized was used as a template,and 4 couples of selected primers were used simultaneously to amplify the target fragments by PCR. A best multiplex RT-PCR reaction system was tested by optimizing the annealing temperature,extension time,dNTPs amount,template amount,primer concentration and so on and an optimal quadruple RT-PCR system that could simultaneously detect these four sweet potato RNA viruses was established. The results showed that an accurate and sensitive multiplex RT-PCR method for detecting the four sweet potato viruses mentioned above with respective target band had been successfully established by challenge tests in which there would be no crossover among the virus primers. The multiplex RT-PCR method established in this study could detect four kinds of sweet potato virus at the same time. It was not only accurate and sensitive,but also reduced the cost of detection and improved the efficiency of virus detection.

  • JI Xiang, SONG Zhicheng, WEI Xiaoling, YANG Yu, SUI Jiongming, GUO Baotai
    Abstract (33) PDF (28) RichHTML (23)

    The purpose was to prepare polyclonal antibody against the recombinant double CP of Potato leafroll virus (PLRV)and Potato virus S (PVS),and apply the polyclonal antibody to indirect ELISA and DAS-ELISA detections of PLRV and PVS.Prokaryotic expression vector pET22b-LRCP/SCP of the fused double CP gene of PLRV and PVS was constructed.After replacement of lysozyme treatment by ultrasonic disruption,inclusion body protein was extracted from the recombinant strain BL21(pET22b-LRCP/SCP),the target protein(recombinant double CP)was purified by nickel ion affinity chromatography and high-purity target protein of 51.2 ku was obtained.The high-purity recombinant double CP was used as antigen to immunize rabbits to prepare an antiserum with a titer of 1∶128 k.Specific reactions were respectively observed between the purified polyclonal antibody (IgG) against the recombinant double CP and the positive standard of PLRV or PVS and no cross-reaction was found between the purified IgG and other four potato major viruses (PVX, PVY, PVA and PVM). The purified IgG against the recombinant CP with the diluted concentration of 1∶3 200 still positively reacted with PLRV or PVS in indirect ELISA detection.The purified IgG and the alkaline phosphatase-conjugated IgG both with the diluted contraction of 1∶100 also positively reacted with PLRV or PVS positive standard in DAS-ELISA detection.The results showed that one type of the prepared IgG against the recombinant double CP could detect two viruses of PLRV and PVS by DAS-ELISA or indirect ELISA.

  • LU Xiaoyue, WANG Ziye, HAN Jianwei, XU Lu, ZHANG Xiaofei, HAN Jie, WANG Zhigang, LIU Yue, SUO Xiangmin, YAN Aihua
    Abstract (57) PDF (6) RichHTML (34)

    In order to clarify the mechanism of pyroligneous acids improving replantation soil,the effect of pyroligneous acids treatment on plant growth was studied by field experiment using apple rootstock-Malus micromalus as experimental material.The main physical and chemical properties and enzyme activities of soil in July and October were analyzed based on Illumina high-throughput sequencing to analyze the changes of microbial diversity in rhizosphere soil.The results showed that compared with the control,the annual increase of plant height,ground diameter and leaf area of Malus angustifolia seedlings were significantly increased after 100-fold pyroligneous acids irrigation.Pyroligneous acids root irrigation treatment significantly increased the contents of main nutrients and enzyme activities in the soil of replanting disease.The contents of soil organic matter,total nitrogen,alkali hydrolyzable nitrogen,available phosphorus and available potassium were 1.31,1.38,1.20,1.60 and 1.65 times of CK1,respectively in July,and 1.12,1.03,1.58,1.40 and 1.25 times of CK2 in October,respectively.Sucrase and urease activities increased significantly in July and October.Pyroligneous acids increased the microbial diversity of rhizosphere soil in summer and autumn.Under CK and pyroligneous acids treatments in July and October,the top five dominant gates of rhizosphere bacteria were Proteobacteria,Acidsobacteria,Gemmatimonadetes,Chloroflexi and Rokubacteria;at the genus level,they were mainly uncultured_bacterium_c_Subgroup_6, uncultured_bacterium_f_Gemmatimonadaceae, uncultured_bacterium_o_Rokubacteriales, RB41 and MND1. The top five dominant gates of rhizosphere fungi were Ascomycota,Basidiomycota, Mortierellomycota,Chytridiomycota and Glomeromycota.At the genus level,they were mainly Cladosporium,Mortierella,Ilyonectria,Guehomyces and Fusarium.According to the correlation network map,the beneficial bacteria RB41 and uncultured_bacterium_f_Gemmatimonadaceae in the rhizosphere and the pathogenic fungi Fusarium and Ilyonectria were negatively correlated with other populations.Pyroligneous acids root irrigation can increase soil nutrients and enzyme activity,increase soil microbial diversity,improve soil microbial community structure,promote plant growth,enhance plant resistance and reduce the harm of replanting disease.

  • JIA Zhiqiang, XU Yunyu, GAO Xue, TAO Hongzheng, CHEN Zengmin, LIU Yating, LI Yongzhong
    Abstract (20) PDF (9) RichHTML (11)

    In order to study the response mechanism of pepper CaWRKY30 transcription factor and Tomato spotted wilt orthotospovirus,it was experimental materials with pepper Xiangyan 11.The CaWRKY30 coding sequence was obtained by RNA extraction,RT-PCR,split gel and cloning.Biological information analysis results showed that CaWRKY30 full length was 1 122 bp,encoding 373 amino acids,the gene encoded protein contains 1 WRKY conservative domain and 1 C2H2 domain,belonged to a typical Ⅱ(e)subfamily member.System evolution analysis showed that the relative relationship with the potato StWRKY22 amino acid sequence was recently.It was found that CaWRKY30 was positioned in the nucleus and cell membranes in its cigarette seedlings,and leads to cell membranes.The results of Real-time fluorescence quantitative PCR analysis showed that the viral accumulation of Tomato spotted wilt orthotospovirus mechanical friction-vaccination was found that the viral accumulation was gradually increased from 1 to 14 days after inoculation,and virus accumulation reached its maximum in 14 days,after inoculation 14 days,viral accumulation gradually declined.At the same time,CaWRKY30 was induced by Tomato spotted wilt orthotospovirus,when the inoculation 1-14 days,the CaWRKY30 expression was raised,and the peak was reached in 14 days,the expression in 14 days gradually decreased.In summary,it obtained the CaWRKY30 transcription factor gene sequence,which was located in the nucleus and cell membrane,and preliminarily explained the expression trend of CaWRKY30 transcription factors under the stress of Tomato spotted wilt orthotospovirus.

  • JI Ying, SUN Feng, WU Shuhua, LI Shuo, TU Liqin, GAO Danna, CUI Xiaoyan, CHEN Xin, JI Yinghua, GUO Qingyun
    Abstract (26) PDF (15) RichHTML (11)

    To characterize the genomic structure of Cowpea mild mottle virus (CpMMV)Jiangsu isolate and clarify its taxonomic status and evolutionary characteristics,4 pairs of specific primers were designed and the genomic fragments were amplified using cDNA obtained from reverse transcription of total RNA of a soybean sample collected from Jiangsu as a temple.The amplified products were cloned and sequenced,and the obtained fragments were assembled to get the full genomic sequence.Sequence analysis revealed the genome of Jiangsu isolate were 8 194 bp in length,containing 6 ORFs and 2 untranslated regions(UTRs):5' UTR(72 nt)and 3' UTR(117 nt).Among the six proteins encoded by CpMMV,CP shared highest amino acid sequence identities with other isolates(96.5%-100.0%),while RdRp(81.1%-98.2%),TGB1(81.0%-97.0%)and TGB3(80.9%-95.6%)shared relatively low sequence identities,indicating CP might be a conservative gene and RdRp,TGB1,TGB3 might show good diversity in different isolates.The phylogenetic analysis based on the whole genomic sequence revealed that Jiangsu isolate was clustered with other CpMMV isolates in a branch and it shared highest nucleotide sequence identities with 2 Chinese isolates(98.2% with Anhui isolate,96.0% with Hainan isolate),compared with other foreign isolates such as the United States,Brazil,India,Mexico,Kenya and so on(<82.7%).These results clarified the genomic structure of Jiangsu isolate,which shared similar character with other CpMMV isolates and phylogenetic analysis revealed Jiangsu isolates clustered with other isolates from China with higher sequences identities,compared with foreign isolates.

  • ZHANG Jian, CAO Xiong, YANG Jianfeng, JIA Shuo, LIU Lin, ADDRAH Mandela-Elorm, FENG Yitong, ZHAO Jun
    Abstract (27) PDF (6) RichHTML (11)

    In order to preliminarily reveal the resistance mechanism of sunflower to Verticillium Wilt at the physiological and molecular levels,the resistant sunflower variety SC89 and susceptible variety LD5009 were used as materials,and the content of H2O2,the activities of defense enzymes superoxide dismutase(SOD),catalase(CAT),peroxidase(POD)and phenylalanine ammonia lyase(PAL)were measured and the transcription level of key genes in disease resistance signaling pathways were analyzed after the sunflower varieties inoculated with the toxin of Verticillium dahliae.The result showed that H2O2 increased rapidly in the resistant variety SC89 at 6 h after inoculation and reached the highest value at 12 h and 36 h,respectively,0.55,0.60 μmol/g,then decline,while in the susceptible variety,although there was a small peak,0.17 μmol/g,at 12 h after inoculation,the accumulation level was far lower than the resistant variety.In the resistant variety,the activity of SOD,CAT,POD and PAL reached the peak rapidly in a short period of time,and then gradually decreased.While the susceptible variety,the peak value of these ROS scavenging enzymes were lower than that of resistant varieties.At the same time,after inoculation,the six disease resistance related genes such as Pr5,Pal and ROS scavenging enzyme gene Sod,Sco and Cat had in varying degrees of induced expression.These results indicated that signal molecules such as SA,JA and H2O2 played important roles in the process of sunflower resistance to Verticillium Wilt.

  • LUO Xiaoyu, SHAN Chenyang, JIA Zhaozhao, ZHANG Xin, LIN Ling
    In order to further utilization of the endophytic antagonistic bacterium S258 isolated from cotton root for biological control, especially to use the volatile organic compounds(VOCs) produced by the strain to control plant disease, Verticillium dahliae and Fusarium oxysporum f. sp. niveum were used as the target pathogenic fungi, and Arabidopsis thaliana was used as the indicator plant, the antifungal activity of the VOCs from the strain against pathogenic fungi and the growth promoting activity against plants were determined by the dual culture on two-section of a Petri dish. The results showed that the VOCs from the endophytic bacterium S258 could inhibit the mycelial growth of pathogenic fungi and at the same time promoted the plant growth. Compared with the negative control E. coli DH5α, the growth inhibition rate of the VOCs against Verticillium dahliae and Fusarium oxysporum f. sp. niveum were 80.9% and 10.1%, respectively. Compared with the blank control without bacteria, the fresh weight per plant of Arabidopsis thaliana treated by the VOCs was 5.3 times that of the blank control. The VOCs from the endophytic bacterium S258 were collected by headspace solid-phase microextraction. Then the compositions of VOCs were analyzed by GC-MS. The VOCs were identified by NIST and WILIY mass spectrometry databases as 30 monomer compounds, belonging to alkanes, alkenes, alcohols, ketones, ethers, aldehydes, esters and heterocycles. According to the peak area of total ion current graph, dimethyl disulfide and indole were most abundant among these compounds. In conclusion, the endophytic bacteria S258 can produce volatile organic compounds with antifungal and growth-promoting activity, which is an important microbial resource for the development of biocontrol products, and its volatile organic compounds also have high research and application value.
  • YUE Runqing, LIU Lu, TIE Shuanggui, XU Xinzhi, CHEN Nana
    In order to breeding maize inbred lines with favorite pest resistant.The modified insect resistant gene Cry1Ab-t was constructed into the plant expression vector pCAMBIA3300m and transferred into the hybrid maize HiⅡ immature embryo with the Agrobacterium-mediated method. The positive transgenic plants were obtained by bar screening and PCR detection.RT-PCR, test strip and ELISA methods were used to detect Cry1Ab-t gene expression in transgenic maize,and the insect resistance was evaluated. The results showed that one hundred and sixteen seedlings were obtained after selecting with bialaphos sodium, and eighty-two seedlings of them were positive by PCR analysis and detection of the Cry1Ab-t gene and bar marker gene. RT-PCR, BT-Cry1Ab/Ac test strip and ELISA methods were used to detect Cry1Ab-t gene expression in transgenic material YA108 with good growth, Cry1Ab-t gene was expressed at transcription and translation level. The results of insect identification indicated that the non transgenic maize filaments were seriously infested by corn borer. However, the transgenic maize YA108 had a high level of insect resistance and stable insect resistance. The non transgenic maize was bitten seriously in the late stage of silking, and there were many boreholes in the stem and mold in the wound, while the transgenic maize YA108 was not damaged. After field inoculation, YA108, the Cry1Ab-t transgenic maize, had good resistance to Asian corn borer in both leaves and filaments. It could kill the larvae of Asian corn borer in a short time and reduce the mildew caused by insect pests to a great extent. The results of indoor and field indirect insect identification showed that the resistance rate of YA108 was detected to be Class 1 at each generation, showing high resistance level to Ostrinia furnacalis.
  • FU Jing, SUN Meng, MA Chunhui, HUANG Yonghong
    To explore the botanical agents to prevent and control apple ring spot disease,the inhibitory of the four common of Allium plant extracts,on the hypha growth of Botryosphaeria berengriana were tested.On this basis,the metabolites of the four Allium plants,Chinese leek,garlic,onions and welsh onion,were analyzed by metabolomics methods,and the suppressive effects of the main components of the four Allium plants on the mycelial growth of B.berengriana and the incidence of the apple ring disease on the apple fruits were also determined.The results showed that in the whole experiment period the inhibition of four Allium plant extracts(1×)on the growth of mycelia of B.berengriana was as high as 100%.78 metabolites were detected in the four Allium plants.Among them,the three main components,pyroglutamic acid,phosphoric acid and citric acid,inhibted the growth of mycelia of B.berengriana by 29.10% to 100.00%,and inhibited the incidence of ring disease on apple fruit caused by B.berengriana by 44.38% to 91.45%.The results of this study laid a theoretical foundation for further understanding and developing the antimicrobial components in Allium,and provided a potential way for the prevention and treatment of apple ring disease.
  • NIU Xiaoxiao, LI Xiaobo, SUN Yi, MA Hailin, ZHANG Jie, LIU Yafei, HAO Yaoshan, CUI Guimei
    Maize stalk rot is not only widespread in China,but also a worldwide disease,which seriously affects the yield and quality of maize. Its distribution and loses caused by the disease,its pathogenic microorganisms and their identification and the evaluation for resistant germplasm resources are briefly discussed. It is indicated that the linkage between the resistance evaluation and breeding is not sufficiently close. The research progresses in genetic regulation and molecular biology of the disease resistance in maize are introduced,and some reference suggestions for further research are put forward.
  • YANG Xiangyun, LIU Fang, ZHAO Qian, SONG Shuishan, ZHANG Liping
    In order to determine the bacterial quorum sensing (QS) signaling molecule, N -acyl-homoserine lactones (AHLs) induce resistance to fungal diseases in plants. Tomato was used as the test material, Botrytis cinerea was used as the pathogen indicator bacteria, and AHLs signal molecules with different side chain length and side chain modification were pretreated to inoculate the pathogen bacteria, and the long chain signal molecule N-3-oxo-tetradecanoyl was found. 3OC14-HSL had the best resistance to gray mold. Real-time quantitative PCR detection of disease resistance genes revealed that the signal molecule 3OC14-HSL pretreatment significantly induced up-regulation of the genes PI1 and PI2 in the tomato and jasmonic acid (JA) signaling pathway compared with the untreated control group; However, the NPR1 gene related to the salicylic acid signaling (SA) pathway was significantly down-regulated, but the PR1 gene was not significantly changed. Further DAB staining, determination of hydrogen peroxide content, and detection of peroxidase (POD) and superoxide dismutase(SOD)enzyme activities revealed that 3OC14-HSL pretreatment caused a large amount of reactive oxygen species in tomatoes compared to the untreated control group. 3OC14-HSL also could maintain high POD, SOD activity. These results indicated that the long-chain signaling molecule N- 3-oxo-tetradecanoyl-homoserine(3OC14-HSL) could induce resistance to gray mold of tomato, and the resistance effect might be related to the jasmonic acid signal pathway.
  • XIE Bing, ZHAN Xiaoxu, LUO Yanhong, LIU Binxiang, KONG Fanlei, YUAN Jichao
    In order to study the effect of different rootstocks on the disease resistance of tobacco grafted seedlings, and to clarify the mechanism of Yunyan 87 (Y87) as rootstock to improve the resistance of scion Hongdajinyuan (HD) to bacterial wilt, this study used split grafting and raw material band winding method to construct HD/HD grafted and HD/Y87 flue-cured tobacco seedlings respectively, using HD as the scion and Y87 as the rootstock. The PAL activity of HD/HD and HD/Y87 protective enzymes was measured. Finally, mRNA of 5 HD/HD or HD/Y87 were extracted and reverse transcribed to construct a total cDNA library by high-throughput sequencing technology and Illumina HiSeqTM 4000 sequencing platform. After sequencing and filtering low-quality Reads, the reference genome was compared with TopHat2, and the genes expression amount and differentially expressed genes were obtained by Cufflinks and DESeq software Heterogene expression. The results showed that the PAL enzyme activity of HD/Y87 was significantly higher than that of HD/HD at different sampling times, 48 414 474-48 697 874 Clean Reads and 38 272-40 938 genes were obtained from four samples, respectively, and the number of selective shear events of HD/Y87 was higher than HD/HD. After comparing the gene expression between HD/Y87 and HD/HD, 3 904 differential genes were obtained, 3 096 genes were up-regulated, 808 genes were down regulated; among the up-regulated genes, there were 3 genes ecoding phenylalanine ammonia lyases, 5 genes ecoding Myb family transcription factors, and 5 genes ecoding polyphenol oxidase involved in lignin synthesis, it also had 2 disease-related proteins and 3 genes ecoding ERF transcription factors. These results showed that Y87 as rootstock could improve the activity of HD PAL and gene expression of various resistance genes (including PAL, PPO and disease related protein) in scion, so as to improve the resistance of HD to bacterial wilt and other diseases.
  • HE Fumeng, LI Xiuyu, ZHAO Xiaocan, WU Jiawen, ZHU Yuanfang, ZHOU Lei, SHI Qihai, LIU Di, LI Fenglan
    A plant expression vector pBI121 -StPR1 was constructed to clarify the role of potato StPR1 gene in disease resistance, and introduce StPR1 gene into tobacco by Agrobacterium transformation method. The disease resistance and physiological characteristics of transgenic tobacco were investigated using different pathogen treatment, including bacterial disease soft rot (E. carotovora subsp. Carotovora Borgey, Ecc; E. chrysanthemi Burkholder. Atroseptica Dye, Ech; E. carotovora subsp. Mc Fadden et Dimock, Eca), bacterial wilt (Ralstonia solanacearum, RS) and fungal disease dry rot (F. sambucinum, F. avenaceum). The results showed that the diameter of lesions leaves increased with the prolongation of stress time in transgenic tobacco and wild type (WT) under the pathogen stress, and the diameter of transgenic tobacco lesions were significantly smaller than WT. In the physiological characteristics analysis, the physiological indexes of leaves increased with the prolongation of stress time in WT and transgenic tobacco, but the activities of SOD, POD and CAT in transgenic tobacco were all increased to different degrees compared WT. The results of disease resistance and physiological characteristics showed that transgenic tobacco had stronger resistance to pathogenic bacteria and fungi, indicating that the StPR1 gene played an important role in the disease resistance of potato, which could provide a theoretical basis for PR1 gene resistance in plants.
  • ZHANG Yingjun, GAO Huimin, LI Ziqian, HU Mengyun, SUN Lijing, LIU Qian, Lü Liangjie, LI Hui
    Fusarium head blight(FHB)is one of the most destructive diseases in wheat,and Fhb1 is the main gene for FHB resistance. In order to screen the germplasms carrying Fhb1 gene in Huang and Huai winter wheat region,336 wheat cultivars from Hebei,Henan,Shandong,Shaanxi,Jiangsu and Anhui were detected by TaHRC-Kasp and His-InDel markers. Two cultivars(Shijiazhuang 75 and Zijingbai)from Hebei Province were screened to carry Fhb1 gene. Sequence analysis showed that the His gene sequences of these two cultivars were same as that of Sumai 3(FHB resistance type). Principal component analysis(PCA)of 336 materials was performed using 9 779 SNP loci and showed that Shijiazhuang 75 and Zijingbai had close genetic relationship with Jiangsu materials. Shijiazhuang 75 was bred in the early days of the founding of China. Zijingbai was a landrace in Hebei Province. These two materials carried Fhb1 gene,which indicated that Fhb1 gene might be distributed in some local germplasms in China at first. But it was eliminated under artificial selection pressure in the process of modern wheat breeding. The results of this study provided valuable genetic information and parent materials for FHB-resistant wheat breeding in Huang and Huai winter wheat region.
  • SONG Zhenjun, LI Zhiyong, WANG Yongfang, QUAN Jianzhang, MA Jifang, BAI Hui, DONG Zhiping
    In order to quickly detect the conditions of Aphelenchoides besseyi contamination in millet seeds and understand the population variations of Aphelenchoides besseyi from different regions, a total of 99 millet seed samples collected from different millet production regions of China were detected by PCR technology, and the population variation of Aphelenchoides besseyi was analyzed. The results showed that the specific primers designed according to the 28S rRNA-D2/D3 fragment of Aphelenchoides besseyi had a high specificity and sensitivity to millet nematodes, and could amplify a fragment of 245 bp with the lowest test concentration of 0.125 ng/μL Aphelenchoides besseyi. Among the 99 millet seed samples, 33 samples were detected to be contaminated, in which the contamination rates ranged from 33.3% to 100%, and they mainly distributed in spring millet areas. The sequence analysis of 28S rRNA fragments from 33 positive samples revealed that there were 29 variable sites and 22 haplotypes, of which the haplotype AB1 was the dominant haplotype. The haplotype genetic diversity of Aphelenchoides besseyi was the most abundant in Zhangjiakou, Hebei Province and Songshan District, Inner Mongolia. In this study, a PCR-based detection method was established to detect Aphelenchoides besseyi in millet seeds with a good specificity and high sensitivity, which could be used to detect the millet seeds carrying Aphelenchoides besseyi. The millet nematode is a major disease in summer millet areas, but with the millet exchange between spring and summer millet areas, it has become a disease in spring millet area. The seed carrier may be the main primary infection source. The 28S rRNA sequences of Aphelenchoides besseyi from different geographic origins were diverse, and AB1 was the dominant haplotype.
  • FENG Lei, GENG Zengchao, XU Wanli, XUE Quanhong, SUN Ningchuan, GU Yuzhong, TANG Guangmu
    To explore the interaction between the biochemical metabolism of walnut branches and the disease resistance of trees under the stress of Jugladis canker.Randomly selected from health, mild, moderate and severe degree of 4 kinds of disease plant each 7 plants, then use Duncan (P<0.05) and single factor analysis of variance blade 3 branches in 3 different antioxidant enzyme activity, multivariate linear regression analysis by using the PAL (phenylalanine ammonia-lyase) activity, POD (peroxidase) activity and Pro (proline) of branches,and walnut base stem relates to the degree of disease (disease spot size).Results showed that the change of the three kinds of antioxidant enzyme activity had certain difference, the PAL activity peak appears in the mild disease leaves and moderate disease branches, while the POD activity of maximum health plant leaves and branches moderate disease, leaf Pro and POD activity of showed similar rule, samples were significantly higher than other disease activity (P<0.05).In addition, the activity of branch Pro had a bimodal characteristic, that is, its activity increased rapidly at the initial stage of infection, while its activity decreased significantly if the disease was further aggravated, and increased significantly with the development of disease.The minima PAL and Pro activity appeared in the early stage of disease infection, and POD activity minima appeared in the late stage of disease development.Correlation analysis showed that POD activity and walnut growth (walnut base stem) had significant negative effects on disease degree, and the correlation reached -0.76 (P<0.01) and -0.85 (P<0.01), respectively.The disease degree was significantly affected by Pro, and the correlation was 0.52 (P<0.01).Therefore, during the infection process of rot disease, increasing the growth of walnut, that is, increasing the base and stem of walnut, has a strong inhibitory effect on the infection process of rot disease. In addition, it also showed that the increased POD activity in walnut plants is conducive to strengthening the resistance of walnut to rot disease.
  • LEI En, GENG Yongke, CHEN Lufa, YANG Yongbing, WANG Yuedong, TANG Qiyuan
    The objective of the study was to investigate the effects of nitrogen fertilizer management pattern and planting density on the yield formation, stalk rot and ear and kernel rot of summer corn in field condition of Southwest China. Two levels of nitrogen fertilizer management pattern were arranged, i.e. conventional nitrogen fertilization(CNP) and nitrogen fertilizer reduction plus deep application in holes between plants and rows(RDNP). And three levels of planting density were designed:commonly used rare-planting(D1, 52 500 plants/ha), densification Ⅰ(D2, 67 500 plants/ha) and densification Ⅱ(D3, 82 500 plants/ha). The yield and its composition, dry matter accumulation, photosynthetic performance and other factors that affected the mechanical harvest quality such as the incidence and severity of maize stalk rot, ear and kernel rot were analyzed. The results revealed that nitrogen fertilizer management pattern had no significant effect on the yield, but the nitrogen partial productivity was 33.7% higher in RDNP than in CNP. RDNP restrained the declining extent of net photosynthetic rate(Pn), leaf SPAD value and leaf area index during the grain-filling stage, which made up for the insufficience of grain numbers per ear formed before flowering, and stabilized the dry-matter accumulation and yield. The RDNP significantly reduced the incidence and severity of maize stalk rot by 4.8 percentage points and 26.8%, respectively, but had little effect on the incidence of ear and kernel rots compared to CNP. The grain yields of D2 and D3 were greater than that of D1, but the sustaining yield increase rate of D3 was significantly lower than that of D2. The incidence and severity of stalk rot and ear and kernel rot were relatively high in D3 than in D2 and D1, while there was no significant difference between D2 and D1. The combination of RDNP and D2 was able to increase the maize yield, improve nitrogen partial productivity, and control the occurrence of maize stalk rot and ear and kernel rot effectively, so as to reduce the risk of lodging and stem breaking. The results could provide the theoretical basis for increasing the production and facilitating the mechanized harvest of summer corn in Southwest China.
  • SONG Jian, XUE Jun, JIN Fengmei, SUN Haibo, ZHANG Yue, WANG Shu, FAN Huan, ZHOU Xiangming, CHEN Rui
    There exists the compound infection of Tomato chlorosis virus (ToCV) and Tomato yellow leaf curl virus (TYLCV), and the incidence of the two diseases presents a tread of increase in recent years, which becomes a new threat to tomato farming. In order to study the interaction and variation of the two virus genes after single and mixed infection, the molecular identification and sequence analysis of the CP gene and the HSP gene of ToCV and the gene of TYLCV occurred in Tianjin were carried out. The results showed that, compared with the single infection samples, 6 base mutations of TYLCV were found in mixed infection samples, i.e. 73rd A→C, 92nd A→G, 347th C→T, 1 209th C→T, 1 618th A→G and 2 107th A→T, among which the 73rd and 92nd mutations were not in the coding region and the other four were located in the ORF box with 3 missense mutations and one samesense mutation(1 209th). There was also one samesense mutation in the CP gene of ToCV. There were 4 base mutations in HSP gene of ToCV, among which the 826th T→C and 1 166th G→A were samesense mutations, while the 1 395th A→G and 1 630th A→G were missense mutations. The accumulation amount of TYLCV and ToCV in tomato samples after single infection and mixed infection were analyzed by RT-qPCR. The results showed that the accumulations of TYLCV and ToCV had no significant difference between single infection and mixed infection. In the mixed infection samples, the copy of TYLCV was about 262-436 times that of ToCV.
  • ZHANG Jingjing, ZHANG Haiying, PAN Xiuqing, XU Yong, REN Yi, GAO Xiurui, LI Bing, SHI Yufan, DANG Jige, YANG Mingzhu, WU Yanrong
    This study aimed to screen the watermelon varieties and germplasms resistant to fusarium wilt, anthracnose and powdery mildew in Hebei Province, and analyze the related resistance genes, which could provide a reference for breeding disease-resistant varieties. The modified CTAB method was used to extract the DNA from watermelon bud, and the DNA concentration was determined by Ultramicro spectrophotometer. After the DNA was diluted to 2-10 ng/μL, they were detected by KASP. The molecular markers of resistance to fusarium wilt, anthracnose and powdery mildew of watermelon were developed by XU Yong's team. The resistant genes related to fusarium wilt, anthracnose and powdery mildew of watermelon were identified by high-throughput KASP markers. Totally 130 watermelon materials were tested, including varieties or advantaging combinations (Xingyan No.7, Meijia, Meisheng, Guifei, 17-11 and so on) that have been approved or will be approved in Hebei Province in recent years, and some excellent germplasms (Huazaolü,JB-1,JB-3,901xin and so on). 3Kang302 was used as the disease-resistant control and GBZG as the susceptible control. The result showed that 33 materials contained fusarium wilt resistance gene Fon-1, 19 contained anthracnose resistance gene AR1, 7 contained powdery mildew resistance gene PM1, 5 contained Fon-1 and AR1, 1 contained AR1 and PM1, and 1 contained all three resistance genes(Fon-1, AR1 and PM1). According to the result of KASP, the materials were clustered, and divided into 4 categories:12 materials resistant to powdery mildew without detection signal or with heterozygous resistance, 67 resistant to powdery mildew or susceptible to at least two diseases, 38 resistant to fusarium wilt or anthracnose, and 13 resistant to fusarium wilt or anthracnose or powdery mildew without detection signal or with heterozygous resistance.
  • HOU Lu
    In order to study the genetic rule of resistance to stripe rust in Qinghai spring wheat cultivar Gaoyuan 363, Qinghai spring wheat adult stage stripe rust resistance cultivar Gaoyuan 363 was crossed with the susceptible spring wheat cultivar Taichung 29 (T29) to produce the F2:3 segregating populations. The stripe rust resistance was identified separately in Xining and Huzhu for two years. The inheritance effects of stripe rust resistance in Gaoyuan 363/T29 F2 populations was analyzed by the method of single generation of joint segregation analysis using mixed inheritance model of major gene plus polygene. Frequency distributions results of Gaoyuan 363/T29 F2:3 populations the infection type and disease severity data showed that:tested on two places, Xining and Huzhu, and in two years for Gaoyuan 363/T29 F2:3 populations, the disease severity and infection type presented a bimodal distribution, which was uncontinuous, but was continuous in some parts. It preliminarily indicated that stripe rust resistance of Gaoyuan 363 was jointly controlled by major gene and minor genes; the result of inheritance model analysis showed that, for Gaoyuan 363 tested in both environments, whether using the disease severity or the infection type data, the most fitted genetic model for stripe rust resistance was controlled by two major genes and partially by minor genes, and the two major gene interactions (C-1:2MG-ADI additive-major-epistatic interaction,C-5:2MG-AED complete dominance effect,C-6:2MG-EEAD equal dominance effect) were different.
  • FU Jing, LIU Yanfeng, MEI Mei, HUANG Yonghong
    In the preliminary study,the incidence of Fusarium wilt of banana and the disease caused by root-knot nematode were significantly reduced by Chinese leek. It was deduced that some potential biological fungus with antifungal and nemotocidal activity existed in the Chinese leek. In the present study the rhizospheric and endophytic fungus communities and diversities were comparatively analyzed,aiming to provide theoretical basis for isolating and identifying biological fungus with antifungal and nematocidal activity in Chinese leek. 18S rRNA from the samples of Chinese leek rhizosphere soil,leave and root were sequenced on the Illumina Miseq platform,and the datas were comparatively analyzed using bioinformatics. The results showed a total of 348 484 high quality sequences and 123 operational taxonomic units(OTUs) was obtained from the Chinese leek rhizosphere siol, leave and root. The Chao,ACE,Shannon index of rhizospheric fungus were significantly higher and Simpson index was significantly lower than that of endophytic fungus(leave and root). The rhizopheric fungus was mainly composed by Ascomycota(67.20%) and Basidiomycota(24.44%). The endophytic fungus was mainly composed by Ascomycota,91.39% in leave and 96.60% in root. In the identified five fungus phyla,the amount of Ascomycota in endophytic fungus was significantly higher than that in the rhizophytic fungus,the other fungus phyla was significantly lower than that in the rhizophytic fungus. The fungus community in the leave and root was slightly different,but not significant. The present study showed significantly difference in the rhizophytic and endophytic fungus communities. The diversity and richness of rhizophytic fungus were significantly higher than that of endophytic fungus. The findings of the study provide reference to isolate biological fungus with potential antifungal and nematocidal activity from Chinese leek.
  • ZHANG Wenli, FAN Li, LIN Qimei, ZHAO Xiaorong, LI Guitong
    In order to study the number of microbes,especially Fusarium and Phytophthora,the greenhouse soil was sprayed with a series volumes of wood vinegar and then incubated at 25℃ for 35 days. The results showed that the pH of each treated soil changed little during the incubation.Generally,wood vinegar had no significant effect on soil pH except on the 7th days,except when the dose reached 3.3 mL/kg,the soil pH was significantly reduced by nearly 0.2 units.At initial period of incubation,the mineral nitrogen content in the soil sprayed with wood vinegar was slightly reduced for 15.1-28.2 mg/kg.However,as the incubation time prolonged,the content of mineral nitrogen in all treatments gradually increased to a similar level (324.9-344.8 mg/kg).The amounts of culturable bacteria,fungi and actinomycetes in the soils sprayed with different volumes of wood vinegar were significantly different from that in the control soil only on some days.But,on the 14th day, the number of culturable actinomycetes in the soil added with 1.3, 3.3 mL/kg wood vinegar was 31.4% and 34.4%,respectively,lower than that in the control soil.On the 21st day,the number of culturable bacteria in the soil added with 0.7,1.3 and 3.3 mL/kg wood vinegar was 20.2%,24.8% and 40.6% lower,respectively,lower than that in the control soil.And at this time,the number of culturable fungi in the soil added with 0.3,0.7 and 3.3 mL/kg was 45.9%,35.5%,36.6%,respectively,lower than that in the control soil.The amounts of Fusarium and Phytophthora were greatly changed in the soils added with different volumes of wood vinegar,however,they showed little difference from the control soil.In conclusion,wood vinegar,acting as an acidic liquid,had no significant effect on soil mineral nitrogen,culturable bacteria,fungi,actinomycetes,as well as the amounts of Fusarium and Phytophthora,even though there was a certain influence on soil pH.It could be speculated that wood vinegar had almost no impact on Fusarium and Phytophthora.Hence,it was not a suitable fumigant for soil,and its impact on alleviating soil-borne might be limited.
  • GUO Yue, JIANG Pingping, PAN Leilei, ZHOU Wenjie, XU Lei, ZHANG Ruqin, SUI Jiongming, GUO Baotai, WANG Jingshan, QIAO Lixian
    The chitinase gene was cloned and its function was further analyzed by genetic transformation, aiming at exploring the role of chitinase gene in resisting fungal diseases in peanut.The DNA (1 779 bp) and cDNA (795 bp) of peanut chitinase gene were obtained successfully by PCR and RT-PCR amplification, with the genomic DNA and cDNA of peanut variety Huayu 23 as templates respectively.The sequence alignment result between DNA and cDNA showed that peanut chitinase gene contained three exons and two introns, conforming to "GT……AG" rule in intron splicing. The cDNA coding sequence contained 795 bp, coded for a 265-amino acid protein, and was named by Ah-Chi, which was registered in NCBI (GenBank accession No. HQ439775). As determined by Blast analysis, the Ah-Chi protein had homology with proteins from Oryza sativa (83%), Zea mays (83%), Medicago sativa (72%), Glycine max (58%) and Arabidopsis thaliana (49%). The over-expression vector pCAMBIA1301-Ah-Chi was constructed successfully by substituting Gus of pCAMBIA1301 for Ah-Chi, and then was transformed into peanut embryonic leaflets explants by Agrobacterium EHA105 mediated transformation. The regenerated plants were then obtained by grafting and transplanting those regenerated somatic embryo seedlings.These transgenic positive plants were further screened and verified by PCR amplification, and the increased expression level of Ah-Chi was confirmedin transgenic plants by RT-PCR amplification. Cercosporidium personatum was inoculated to the detached leaves of transgenic and non-transgenic plants. Seven days later, it was found that the non-transgenic plants showed more serious leaves' browning and necrosis than transgenic plants, which indicated that the disease resistance of transgenic plants were enhanced.
  • JIA Zhenhua, LIU Fang, SONG Cong, HUANG Yali, MA Hong, SONG Shuishan
    Harpins protein expressed by hypersensitive response and pathogenity gene(hrp) can induce the defense response of plant to diseases and insect pests of plant. By the way of agar solid plate, Erwinia carotovora pv. carotovora strain Ecc36 can produce high levels of extracellular enzymes. The Ecc36 strain could elicit the hypersensitive response(HR) in tobacco leaves. These results showed that some kind of hrp was in Ecc36 strain. Southern Blot analysis of Ecc36 with a hrpN gene probe labeled by DIG-dUTP showed that the Ecc36 strain possesses hrpN gene,named hrpNEccPR. Through nucleotide sequence analysis,a 1 254 bp open reading frame(ORF) of Ecc36 hrpN was revealed. A Harpin protein(named HrpNEccPR protein) encoded by hrpNEccPR comprise 417 amino acid residues with 45.27 ku and pI 5.73 approximately. The deduced amino acid sequence of Ecc36 hrpN shares high homology with Harpin proteins of several other E. carotovora strains. The hrpNEccPR gene was cloned into vector pET28a(+) for expression,and then transferred into the cells of E. coli strain BL21(DE3). The HrpNEccPR protein was overexpressed in reconstructed BL21(DE3) when the strain was induced by IPTG. The purified HrpNEccPR effectively elicits the HR in tobacco leaves. Those show HrpNEccPR protein has the biological activity of stimulating the immune response of plants,and provide for further study on the mechanism of the defense response induced by HrpNEccPR protein in plant.
  • LAN Suque, LI Guangwei, MENG Yaning, LI Fang, ZHANG Yelun, LI Xingpu
    Wheat powdery mildew is one of the main diseases threaten wheat production in China even all over the world. Screening and development disease-resistant varieties is a safe and effective way for prevention and control of wheat powdery mildew. The purpose of this study is to introduce powdery mildew resistance gene Pm30 into the wheat varieties Jizi 356 with advanced comprehensive agronomic characters and high yield developed by authors. One crosses,Jizi 356/Synthetics He-48 were made. Twelve lines with field resistance to powdery mildew and excellent agronomic characters were developed after six years of offspring screening. Then,seven lines were used for identifying resistance gene Pm30 using Xgwm159 SSR marker. Chinese spring and Pm30 were used as a contrast. The results showed that two new lines 14YF650 and 14YF675 could amplify the 430,460,500 bp polymorphic fragments. It indicated the two lines carrying Pm30 powdery mildew resistance gene derived from wild emmer. Those lines with big spikes,resistant to lodging and excellent agronomic characters could be used directly as parents for wheat powdery mildew resistance breeding.
  • MAO Xiaoyue, WU Jun, MENG Xiaoxia, WEI Ke, ZHANG Zhihui, LAI Xing, XIAO Heng
    In order to explore methods of the reasonable resource utilization on biogas slurry,provide a reference for local biogas slurry agricultural,adjust measures to guide agricultural production with local conditions,and reduce agricultural production costs,this study researched the effect of biogas slurry on leaf mustard yield,quality and control on the disease and pest,explored the application amount of biogas slurry under leaf mustard yield,quality and pest control best-case situation.Compared with the fertilizer control (CK2),in the most areas with biogas application slurry the production of leaf mustard had improved,nutritional quality of leaf mustard had improved,leaf mustard grow better,the yield of leaf mustard were maintained at a relatively high level when the biogas slurry that instead of fertilizer application rate was controlled in the range of 83 333 to 108 333 kg/ha;the quality of leaf mustard achieved the best when the biogas slurry that instead of fertilizer application rate was controlled in the range of 91 667 to 108 333 kg/ha,considering the output and quality of leaf mustard,the biogas slurry used instead of chemical fertilizer would be optimal at 91 667-108 333 kg/ha. A moderate amount of biogas slurry spraying had the benefits to diseases and insect pests prevention and control of leaf mustard. When the biogas slurry seems control during 1 750-2 500 kg/ha,leaf mustard hundred plant bug number close to CK2;when applying biogas slurry content control during 2 250-2 500 kg/ha,the rates of insect pest and disease index mustard were relatively minimum and close to CK2,so in this study,leaf mustard pest control effect was relatively better when the biogas slurry that instead of pesticides application rate was controlled in the range of 2 250 to 2 500 kg/ha. In summary,through the application of compares with two groups of contrast (CK1 and CK2),application of biogas slurry can significantly improve the production of leaf mustard,ensure the good quality of leaf mustard,as well as has good benefit to plant diseases and insect pests prevention and control of leaf mustard,but growth on various aspects of the demand of leaf mustard can be ensured,when application of biogas slurry is controlled in applying a certain content and reasonable,and improve the efficiency of the use of biogas slurry.
  • LI Xiangyang, DAI Dandan, YANG Tiegang, HAO Xi
    As an important component of plant cell wall,expansins have effects on loosening and increasing the flexibility of cell wall,and are thought to have function in many process of plant growth. To study potential function of expansin gene family in potato,we investigated expansin gene family with the whole genome database to analyse its structure,phylogenetic relationship and expression profiles. Potato genome contained 33 expansin genes which belonged to 4 subfamilies (EXPA (21),EXPB (5),EXLA (1) and EXLB (6)) located on 11 different chromosomes. Expansin proteins ranged from 194 aa to 488 aa in size and had conserved domains. All 33 Expansin proteins were predicted to localize in extracellular. Gene structure analysis revealed that seventy percent(23/33) expansin genes had 2-3 introns. Transcriptome analysis showed that the potato expansin genes expressed highly in root,stem,stolon,mature fruit and tuber.
  • ZHANG Shangqing, HAN Xiaoqing, MIAO Zuoqing, WU Zhihui, ZHANG Lijiao
    In order to identify the pathogenic fungi which causing tomato bacterial wilt in Fengnan District of Hebei Province.This study proved the disease as Bipolaris sorokiniana by pathogen isolation,pathogenicity test,morphological observation,and rDNA-ITS gene sequence analyses was caused by Fusarium oxysporum f.sp.radicis-lycopersici(Forl).The result showed that the mortality and morbidity of stem based inoculation were higher than root soaking inoculation.So,the disease with stem based inoculation developed faster.The study provided theoretical basis for the breeding of disease resistance and the screening of the fungicides.
  • WANG Xinghong
    In order to distinguish P.citricarpa, P.citriasiana, P.capitalensis and P.citrichinaensis,upstream primers for P.citricarpa, P.capitalensis and P.citrichinaensis were designed in ITS1 and 18S regions,and these primers were used together with the ITS4 primer.Then,the specificity and annealing temperature of primers were screened,and the sensitivity of the specific primers were verified.Screened primer was used to detect P.citricarpa when DNA was extracted from black/tan spot lesions on fruits or leaves.The results showed that 593 bp specific fragments were only obtained from P.citricarpa by specific primer Pc1/ITS4,551 bp specific fragments were only obtained from P.capitalensis by specific primer Pct4/ITS4,and 706 bp specific fragments were only obtained from P.citrichinaensis by specific primer Pcc1/ITS4,when annealing temperature at 60℃.These specific primers were never amplified any fragment from the common Citrus pathogens.The sensitivity test results showed that the sensitivity of specific primers Pc1/ITS4 and Pct4/ITS4 was 200 pg,and the sensitivity of specific primer Pcc1/ITS4 was 20 pg.The screened specific primer Pc1/ITS4 could detect P.citricarpa from DNA of black spot lesions on fruit.Therefore,using the specific primers,combined with the simple method of DNA extraction,the molecular detection for the pathogen of Citrus black spot could be completed in a short time.
  • LIU Haiye, GAO Weikai, ZHOU Lifei, LI Jincheng, WANG Jialiang, SHAO Jianping, HAN Xiaoyuan, LI Yabing, WANG Wei
    To explore the effect of different leaf age on the yield and quality of flue-cured tobacco,the main cultivars K236 in Luoping tobacco-growing area of Yunnan were used as test materials to construct different flue-cured tobacco varieties with different leaf age. Photosynthetic potential in growth period and economic characters of post-baked tobacco leaf were analyzed. The results showed that with the increase of transplanting age,the survival rate of tobacco seedlings increased first and then decreased,while the field growth period increased; With the advance of fertility in the field of flue-cured tobacco,the photosynthetic potential (LAD) of the treatments decreased first and then increased,and the total LAD of the treatments was the highest in 5 leaves transplanted tobacco seedlings,which was 20.14% higher than that of 6 and 8 leaves respectively,14.82%. The mean leaf angle (MLIA) of the population increased first and then decreased with the increase of leaf age,while the extinction coefficient (K)was an increasing trend.The leaf tobacco leaves with 5 leaves were transplanted with appropriate chemical components and the quality was the best,followed by 4 leaves;6,7,8 leaves,because of its reducing sugar,starch,potassium content does not meet the requirements of high-quality tobacco chemical indicators,poor quality;With the increase of transplanting age,economic traits showed a trend of increasing first and then decreasing. Therefore,the optimum tobacco leaf transplanting age of tobacco leaves in Luoping tobacco-producing areas in Yunnan is 5-leaf-stage,which can shorten the period of nursery and shorten the time of cutting and reduce the time when the high yield value can be maintained. Such as smoke and the proportion of medium and high smoke,improve the grade structure and site structure.
  • ZHAO Huan
    To clone Pinellia pedatisecta agglutinin gene (PPA)from the leaves of Pinellia pedatisecta,analyzed on its biological information characteristics,and observed its subcellular localization.The open reading frame sequence of PPA gene was amplified by PCR method.The recombinant vector pCAMBIA1300-35S-PPA-eGFP was constructed and then transferred into Agrobacterium strain GV3101. Agrobacterium suspensions expressing PPA were injected at different concentrations into Nicotiana tabacum leaves and the subcellular location was observed by confocal laser scanning microscope.It showed that the open reading fragment sequence length of PPA gene was 777 bp,encoding 258 amino acids with GenBank accession number KF154981 and AGV40779,respectively.It contained two conservative B-lectin domains and three mannose binding sites.Sequence alignment demonstrated that the deduced amino acid sequence of PPA,which were 96%,91%,86% and 83% identical respectively,with the corresponding region of Arisaema heterophyllum, Pinellia cordata, Arisaema lobatum and Pinellia ternata.The subcellular location results indicated that the PPA-eGFP was located in the plasma membrane as large spots,but not found in nucleus.The results would provide the foundation for further study the structure and function of PPA gene,and elucidate anti-microbial mechanism of PPA.
  • XIANG Shipeng, HU Risheng, ZHOU Xiangping, XIE Yangjun, ZHOU Jiheng, LI Hui
    Black shank disease is one of the main diseases of tobacco production.The screening,identification of the disease resistance and genetic analysis of tobacco germplasm resources are the base of breeding for disease resistance. In this study,we used Physiological race 1 black shank to identify the resistance to black shank of 49 tobacco germplasm resources and used SSR markers to analysis genetic relationship. The results showed:Among them 24 were resistant,including dayeyongyan,G80,E9,MS212-8;7 were moderate resistant;6 were moderate susceptible;12 were susceptible;6 were high susceptible.The average effective number of alleles of 49 tobacco germplasm resources was 3.06(1.31),and the average Shannon's information index was 1.18(0.36);The 49 germplasm materials were classed into 4 groups at the position of coefficient of 0.66 by the 23 SSR markers. The first group was resistance variety K326;the second group included 6 germplasm resources;the third group included 4 susceptible germplasm resources;the fourth group included 38 germplasm resources. The most of resistance to black shank germplasm was clustered in the fourth group,suggesting the genetic basis of the resistance to black shank germplasm resources was narrow.
  • LIANG Yugang, ZHANG Qifei, ZHOU Jing, LI Yang, TAN Changlong, HUANG Huang
    Abstract (347) PDF (100) RichHTML
    To achieve the food production channels on the rice cultivation of the main "more than one season,two seasons insufficient" and season rice producing areas in China. In this context,a contrast experiment was done to study rice quality and economic efficiency in the ratooning rice,early season rice and late rice. Compared with the early season rice and late rice,ratooning rice realized pesticide zero input,decreased fertilizer and irrigation water application amount,lowered production cost,reduced labor intensity,maintained economic stability. Improved the rate of brown rice,milled rice and head milled rice,decreased rice grain shape,chalky ratio and chalkiness area,increased gel consistency,gelatinization temperature and the contents of amylase,total starch and protein,thereby improved rice grain quality to a certain degree. Ratooning rice met the requirement of the simple and labor saving cultivation and agricultural resources less investment,realized "planting season,two harvests a year",developed channels to increase food production,was of great significance to food security and stability in China.
  • LIANG Yuqin, YANG Yang, LIU Yun, DONG Pan, SONG Bingyan
    Abstract (294) PDF (165) RichHTML
    Soilless media cultivation has become a common form of cultivation in the facilities of horticulture,which as an alternative to soil cultivation.Crop growth in addition to the special requirements of the ecological environment,the characteristics of the matrix requirements are also important.We summarized the physicochemical properties of substrate materials used in production and the effects of different substrate formulations on crop growth; And expounded the method and antibacterial mechanism of using matrix materials to control plant diseases based on the soil-borne diseases existing in soil culture.
  • YANG Dongjing, ZHAO Yongqiang, ZHANG Chengling, SUN Houjun, XU Zhen, XIE Yiping
    Garlic tip blight which caused by Pleospora herbarum is one of the important diseases in garlic production in Xuzhou area.In this study,the biological characteristics of Pleospora herbarum and the selection of high efficiency and low toxicity fungicides was studied to provide theoretical basis for safe production of garlic. The biological characteristics of this pathogen was analysed by cross method. The results showed that the best carbon source in this study was D-fructose,and the best nitrogen source in this study was potassium nitrite,and the suitable pH was from 5-12,with colony diameter from 7.55-9.15 cm. Mycelium was not sensitive to the light,but in darkness the colony diameter which was 7.30 cm was the longest;The lethal temperature of the pathogen was 57℃,5 min. The most suitable temperature was 22℃,and the colony diameter was 7.78 cm. The toxicity of five fungicides to Pleospora herbarum was tested by mycelia growth inhibition. The result showed that the toxicity to this pathogen of these 5 fungicides was significantly different.Among the 5 fungicides tested,the highest inhibition effect to mycelia growth of Pleospora herbarum was observed with 96% difenoconazole,the value of EC50 was 0.017 4;The better fungicides followed by was 98% pyraclostrobin,the value of EC50 was 0.892 7;98.4% chlorothalonil,98.5% kresoxim-methyl and 98% carbendazol had the lowest effect and the values of EC50 were 9.959 0,18.080 4 and 45.387 7,respectively.
  • DENG Peiyuan, YUAN Wei, LI Yuhua, WANG Linqing, LI Changkan
    Abstract (354) PDF (190) RichHTML
    Antennal binding proteins are soluble acidic proteins in insect antenna.It is an important way to clarify ABP physiological function by analysising the binding pattern.The PxylABP gene of Plutella xylostella was cloned using reverse transcription PCR and expressed in Escherichia coli.The specificity of PxylABP binding with 29 compounds was tested through fluorescence competitive binding assay,and the molecular docking of PxylABP with compounds were carried out using AutoDock 4.2.The results showed that PxylABP protein had binding ability to Allylisothiocyanate,Hexane,Hexanal,Indole,2-hexanone and β-Lonone,with the dissociation constants of 0.91,1.81,1.17,2.71,2.74 and 14.95 μmol/L,respcetively;The molecular docking results showed that one hydrogen bond generated between Tyr100 and Allyl-isothiocyanate.These data suggested that PxylABP might be involved in the physiological process that discriminate the cruciferous vegetables and herbivore-induced plant volatiles in Plutella xylostella.
  • WANG Guodong, CHEN Chaoyin, LI Jinjing, PU Limei, GUAN Ruipan, GE Feng, LIU Diqiu
    Abstract (456) PDF (169) RichHTML
    To investigate the function of JsWRKY1, a constitutive expression vector of JsWRKY1 was constructed and transferred into Nicotiana tabacum L.cv Xanthi.There were no visible differences between the positive transgenic plants and WT.The expression levels of several defense-related genes MnSOD, Cu/ZnSOD, CN, NADPH oxidase, and PR1 resistance gene were up-regulated in the transgenic tobacco lines,and the SOD,APX and POD showed significantly higher activities in the transgenic lines than in wild type under normal conditions or after inoculation with C.gloeosporioides. The crude protein extract of transgenic tobacco lines inhibited the hyphal growth of the following four fungi, Botrosphaeria dothidea, Gibberella moniliformis, C.gloeosporioides and Fusarium oxysporum at different degrees.The antifungal activity in vitro plates demonstrated that the activities of SOD in the transgenic tobacco lines were significantly higher than those in WT.Moreover,the transgenic tobacco plants showed strong resistance after inoculation with C.gloeosporioides in the leaves.In conclusion,the JsWRKY1 is a positive transcription factor of J.sigiuata regulating the defense response to pathogens.
  • ZHANG Hong, ZHANG Bin, WANG Chaonan, LI Mei, HUANG Zhiyin, LIU Junfeng
    Abstract (366) PDF (112) RichHTML
    For the disease-resistant breeding of Qingmaye Chinese cabbage,five kinds of inoculation methods(Indigenous bacteria,Seal of indigenous bacteria,Dip method,Injection method,Seed soaking method),different soil pH,different inoculation concentration,illumination and root secretion were compared by use Qiulü 60 as material in this article.The results showed that the effect of soil inoculation was more excellent and stable.In contrast,seed-immersion method was the poorest.The acid soil pH was fit to clubroot break out and the disease index reached the maximum when pH value was 6.5.1 g soil inoculated 0.050 g root was the most suitable inoculation concentration.After light treatment,the disease index was increased,it showed that light had a promoting effect on diseases.Root secretion of tomato,resistant and susceptible hosts could promote the happening of disease.Therefore,in the artificial inoculation test of Qingmaye Chinese cabbage can be the above optimum inoculation method and conditions so as to improve the effect of inoculation.
  • CHEN Hai-xiao, ZHANG Na, SHAN Juan-juan
    Because of improper storage has a lot of sweet potato diseases lead to mildew deterioration.In the paper main research temperature and humidity on the sweet potato storage period prone to disease.Expert consultation method and the literature query method are used to get the sweet potato storage period prone diseases relationship with the environment temperature and humidity.Using the Matlab data fitting,And then through the classification of the disease occurred in the storage of sweet potato,these data to establish evaluation model of sweet potato storage diseases.The model can evaluate the sweet potato storage conditions,sweet potato storage optimum temperature and humidity conditions.The model is beneficial to scientific safety store of sweet potato,reduce economic loss.
  • ZHANG Yu-mei, LI Han-bing, BI Ming-zhao, WANG Zhi, ZHANG Na, YANG Wen-xiang, LIU Da-qun
    Abstract (339) PDF (476) RichHTML
    Wheat sharpeye sport caused by Rhizoctonia cerealis is very important and difficult control disease in wheat production.Exploring new safely,high efficiency control method is an important test in this disease control.Screening and applying the endophytic bacteria is an important focus in biological control of plant disease.In order to acquire endophytic bacteria against R.cerealis and enrich the methods of control wheat sharp eyespot,the endophytic bacteria strains from wheat were isolated by using spread plate method.The antagonistic strains were screened by inhibition zone method and tablet confrontation culture method.The results showed that 4 of 8 plants endophytic bacteria strains isolated from the wheat displayed antagonistic activity to Rhizoctonia cerealis,and W-1 was the best one.The mycelia of Rhizoctonia cerealis were treated with fermentation liquid of W-1 and showed deformity,ablation and fracture.However,the wheat could grow normally treated with fermentation liquid of W-1.Colonization test showed that the isolate W-1 could colonize in wheat stably.
  • YAN De-bo, LU Cai-ge, WANG Jun-li, LIU De-wen, YU Li, LIU Wei-cheng
    Abstract (457) PDF (128) RichHTML
    In order to increase the yield of natamycin produced by Streptomyces lydicus G117,fermentation medium was optimized with methods of Plackett-Burman,path of steepest ascent and Box-Behnken Design.Placket-Burman was applied to screen three main factors that affecting production of natamycin,including corn starch,soybean powder and NaCl.The result indicated that the optimum mass concentrations of the three components in fermentation medium were determined to be 46.15,14.80,5.88 g/L,respectively,with the highest theoretical prediction yield of 2 708.06 mg/L.In subsequent 3 fermentation experiments,the average yield of natamycin for the optimized fermentation medium was 2 718.57 mg/L,which there was no significant difference with the theoretical prediction yield,and increased by 33.2% in comparison with basic fermentation medium.