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Please wait a minute... For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails Select Screening and Identification of Antagonistic Endophytic Bacteria against Asparagus Stem Blight SU Zhuowen, LU Caige, CAI Shulin, ZHANG Taotao, DONG Dan, ZHAO Juan, ZHANG Dianpeng Journal of Henan Agricultural Sciences    2022, 51 (10): 106-113.   DOI: 10.15933/j.cnki.1004-3268.2022.10.012 Abstract （954）      PDF （3081KB）（127）       Knowledge map    Save To obtain endophytic antagonists efficiently inhibiting asparagus stem blight （Phomopsis asparagi），52 strains of endophytic bacteria were isolated from the roots of wild asparagus collected in Miyun District of Beijing and were tested for their bio‑control activity against Phomopsis asparagi using the dual culture method and greenhouse experiments. The results showed that three strains of endophytic bacteria with good inhibitory effects were obtained，and the inhibition rates were 63.70%—85.00%.Among them the strain YS‑G10 displayed the highest antagonistic activity and the inhibition rate against Phomopsis asparagi was up to 85.00%.The strain YS‑G10 could also effectively inhibit asparagus stem blight in the greenhouse experiment and the control effect was 73.44%.Biocontrol‑related character assays showed that the strain was capable of producing protease and cellulase，suggesting that the strain YS‑G10 may control asparagus stem blight by secreting hydrolysis enzymes such as protease and cellulase to destory the cell wall of pathogenic fungi or inhibit the production of pathogenic toxins.By using morphological，physiological，biochemical tests and phylogenetic tree analysis based on 16S rDNA and gyrB sequences，the strain YS‑G10 was identified as Bacillus velezensis. Reference | Related Articles | Metrics Select Screening and Identification of Antagonistic Bacteria of Streptomyces scabies TAI Lianmei, CHEN Zhiyao, WANG Peng, WANG Yuqi, JIN Guanghui, JIN Xuehui, Journal of Henan Agricultural Sciences    2021, 50 (11): 108-116.   DOI: 10.15933/j.cnki.1004-3268.2021.11.013 Abstract （581）      PDF （2474KB）（114）       Knowledge map    Save In order to obtain strains that have antagonistic effects on Streptomyces scabies，181 bacterial strains were isolated from the rhizosphere soil of healthy plants in the potato scab‑infected plot of Keshan Farm in Qiqihar City，Heilongjiang Province.The flat plate stand‑off growth method and the Oxford cup test were used to screen and re‑screen the isolated strains，and a strain BKS51 with obvious antagonistic effect on S. scabies was obtained，with a bacteriostatic diameter of 37 mm，and the potted plant control effect reached 81.0%.The morphological characteristics，physiological and biochemical characteristics of BKS51 were determined，16S rRNA and gyrB gene sequences were analyzed，and the antibacterial spectrum was determined.The results showed that the colony of strain BKS51 was round，milky white，opaque，with fold‑like protrusions，irregular edges.The strain was rod‑shaped，and gram‑positive，nitric acid reduction reaction was positive，and glucose fermentation reaction and MR reaction were negative.Combined with sequence analysis results of 16S rRNA and gyrB，it was identified as Bacillus amyloliquefaciens.BKS51 had an inhibitory effect on a variety of plant pathogens，among them，the inhibition rates on Bipolaris zeicola and Bipolaris oryzae were higher，reaching 67.2% and 62.4%respectively. Table and Figures | Reference | Related Articles | Metrics Select Screening and Control Effect of Endophytic Fungi for Brown Spot Disease of Schisandra chinensis ZHANG Yuqi, REN Yueying, WEN Xiangsui, WANG Yumeng, FANG Ping, LI Baoquan, LENG Shihe Journal of Henan Agricultural Sciences    2021, 50 (8): 94-102.   DOI: 10.15933/j.cnki.1004-3268.2021.08.012 Abstract （220）      PDF （3075KB）（149）       Knowledge map    Save In order to screen the excellent endophytic fungi with better biocontrol effects on the pathogen of Schisandra chinensis brown spot disease， Phoma glomerate（corad）Wollena ex Hoehapf，the conventional culture method in plant pathology was used to culture Phoma glomerate（corad）Wollena ex Hoehapf and observe its colony characteristics and micromorphology，at the same time，the plate antagonistic method was applied to screen the endophytic biocontrol fungi. By measuring the change of cell membrane permeability，soluble protein content，ergosterol content，and chitin content of Phoma glomerate（corad）Wollena ex Hoehapf，the bactericidal mechanism of WG9 fermentation liquid was preliminarily explored. Morphological observation，fungal ITS gene sequencing，and the construction of phylogenetic tree were combined to identify the screened excellent endophytic biocontrol fungi.The results showed that one strain of biocontrol fungi WG9 screened from the endophytic fungi of Schisandra chinensis had better biocontrol effect. The plate antagonistic experiment indicated that its antagonistic rate reached 64. 73% and the antagonistic rate of fermentation liquid was 48. 21%. With the increase of the concentration of the WG9 fermentation broth，the cell membrane permeability and soluble protein content of the pathogenic fungi hyphae increased，while the ergosterol content and chitin content decreased. Morphological observation and molecular biology identified the excellent endophytic fungus as Purpureocillium lilacinum. The present study showed that the endophytic biocontrol fungus WG9 screened from the rhizome of Schisandra chinensis had a good bactericidal effect on Phoma glomerate（corad）Wollena ex Hoehapf，and the WG9 fermentation broth had a certain damage effect on the cell wall of pathogenic fungi. Table and Figures | Reference | Related Articles | Metrics Select Isolation and Evaluation of the Antagonistic Bacterium HJ‑5 against Orchid Stem Rot Disease LÜ Ang, WANG Cheng, TANG Yafang, WANG Lihua, JIANG Yiquan Journal of Henan Agricultural Sciences    2021, 50 (8): 85-93.   DOI: 10.15933/j.cnki.1004-3268.2021.08.011 Abstract （685）      PDF （7569KB）（126）       Knowledge map    Save In order to screen antagonistic bacterial strains for the biocontrol of orchid stem rot caused by Fusarium oxysporum,antagonistic bacteria were isolated and screened from the soil around the roots of healthy orchid seedlings in Xiaogan City，Hubei Province，and their biological control potential was evaluated. The results showed that 8 strains of antagonistic bacteria were isolated，which had good inhibitory effect on the growth of F.oxysporum.16S rDNA sequencing and phylogenetic tree construction showed that all the 8 antagonistic strains were Bacillus spp. B. megaterium HJ‑5 showed good and stable antagonism against F. oxysporum in plate confrontation. Its sterile fermentation broth was added into the virulent plate prepared by PDA medium at 5%. The sterile fermentation broth showed strong inhibitory effect on mycelial growth of Botrytis cinerea，Colletotrichum siamense，F.moniliforme，F.oxysporum，Monilia fructigena，Mucor hiemails，Rhizopus stolonifer，Sclerotinia sclerotiorum and Sclerotium rolfsii，and the inhibition rates were higher than 50%.The sterile fermentation broth of HJ‑5 could maintain the antifungal activity under high temperature，strong acid and alkali,and long‑term UV irradiation.In addition，the key genes sfp and fenB for the biosynthesis of antimicrobial substances surfactin and fengycin were amplified in the genome of HJ‑5.The above results indicate that B. megaterium strain HJ‑5has excellent biocontrol potential against orchid stem rot. Table and Figures | Reference | Related Articles | Metrics Select Screening of Antagonistic Fungi against Soil-borne Diseases of Siraitia grosvenorii and the Antifungal Activity of Their Fermentation Products#br# ZHANG Ze, DENG Yecheng, CHEN Gan, WANG Ruihao, ZHANG Yanling, DENG Zhiyong, LAN Fusheng, GUO Lixia, ZHANG Chuanmei, LIANG Baoming, LUO Haiyu, ZHANG Mingliang Journal of Henan Agricultural Sciences    2021, 50 (6): 91-98.   DOI: 10.15933/j.cnki.1004-3268.2021.06.011 Abstract （908）      PDF （2827KB）（291）       Knowledge map    Save The coating plate method and plate confrontation method were used to isolate and screen the antagonistic fungi against soil-borne pathogens ( Fusarium solani and Sclerotium rolfsii) from the rhizosphere soil of healthy Siraitia grosvenorii.The antagonistic fungi were identified according to their morphological and molecular biology characteristics. Mycelium growth rate method was employed to evaluate the antifungal activity of metabolites from antagonistic fungi.The purpose is to provide a scientific basis for the green control of soil-borne diseases of Siraitia grosvenorii.The results showed that a total of 25 fungi were isolated and 4 antagonistic fungi were screened out.The inhibitory rates of the four antagonistic fungi against Fusarium solani and Sclerotium rolfsii were 42.01%—63.56% and 59.81%—74.17%, respectively.The four antagonistic fungi were identified by morphological observation and molecular biology technique as Trichoderma asperellum, Aspergillus aculeatus, Talaromyces angelicus and Penicillium janthinellum, respectively.Under liquid fermentation conditions, the ethyl acetate extracts from Trichoderma asperellum, Aspergillus aculeatus and Talaromyces angelicus metabolites showed obvious antimicrobial activity against Fusarium solani,with EC 50 values of 1.290 1,2.637 0,3.646 9 mg/ mL,respectively.The ethyl acetate extracts from the fermentation products of Aspergillus aculeatus, Talaromyces angelicus and Penicillium janthinellum showed good antimicrobial activity against Sclerotium rolfsii with EC 50 values of 1.740 4,3.925 1,0.636 2 mg/mL,respectively.Under the conditions of solid rice fermentation, the fermentation product of Trichoderma asperellum had good antimicrobial activity against Fusarium solani and Sclerotium rolfsii,with EC 50 values of 2.339 4 mg/ mL and 1.941 8 mg/ mL.It is suggested that the 4 antagonistic fungi have potential application value for the control of soil-borne diseases of Siraitia grosvenorii. Related Articles | Metrics Select Isolation of Antagonistic Endophytes against Myrica rubra Wilt and Their Antagonistic Mechanism CAO Pengfei, LIU Qing’e Journal of Henan Agricultural Sciences    2021, 50 (4): 96-105.   DOI: 10.15933/j.cnki.1004-3268.2021.04.013 Abstract （809）      PDF （3253KB）（193）       Knowledge map    Save In order to isolate and screen antagonistic endophytes for the control of M.rubra wilt disease,healthy M.rubra, Houttuynia cordata, phoenix and honeysuckle were used as materials to screen the antagonistic endophytic strains.The changes of cell membrane,cell wall,respiratory metabolism,RNA content and topoisomerase Ⅰ activity were determined to study the antagonistic mechanism.The results showed that 14 strains of antagonistic endophytes against M.rubra wilt were isolated from four plants,of which the FWB1J strain and YMB1J strain had the best antibacterial effect.And these two strains were identified as Trichoderma sp.and Candida sp.respectively. Their MICs were 0.400 0 g/mL,their EC 50 were 0.034 7 g/mL and 0.029 0 g/mL respectively,their EC 90 were 0.315 5 g/mL and 0.254 6 g/mL,respectively.After being treated with the extracellular metabolites of two dominant endophytic strains,the content of N-acetylglucosamine and chitinase activity of pathogen were significantly higher than those of the control,and reached the maximum at 36 h,among them,the content of N-acetylglucosamine in the EC 90 group of YMB1J strain was 176. 700 μg/ g higher than that of the control.The leakage of extracellular soluble sugar and soluble protein increased gradually,and reached the maximum at 10 h.The content of ergosterol was significantly lower than that of the control group,and the EC 90 group of FWB1J strain was 82.460 μg/g lower than the control.The content of RNA in pathogen was always lower than that of the control group,and the RNA content of the EC90 group of FWB1J strain was the lowest,which was 16.450 μg/g lower than that of the control group at 60 h.The activities of succinate dehydrogenase and malate dehydrogenase were significantly lower than that of the control group,and the activities of the two enzymes in the EC 90 group of FWB1J strain were decreased by 2.750 U/mg and 318.330 U/mg at 72 h,respectively.Theses indicated that FWB1J and YMB1J strains could destroy the integrity of cell wall, increase the permeability of cell membrane, inhibit nucleic acid synthesis and respiratory metabolism,and then inhibit the growth of the pathogen and even promote their death. Related Articles | Metrics Select Screening and Colonization Characteristics of Efficient Endophytic Antifungal Bacteria against Botrytis cinerea GAO Zhenfeng, LI Na, ZHANG Xiaoyu, HAN Jucai Journal of Henan Agricultural Sciences    2020, 49 (3): 88-100.   DOI: 10.15933/j.cnki.1004-3268.2020.03.012 Abstract （176）      PDF （7664KB）（165）       Knowledge map    Save In order to screen out highly effective antifungal bacterium,which can be well colonized in the rhizosphere,root and leaf of tomato and has good control effect on tomato gray mold,the methods of plate screening,field screening,rifampicin resistance marker,morphological identification,physiological and biochemical identification,16S rRNA, gyrA and gyrB identification were used to screen and study the colonization characteristics and taxonomic status of highly efficient antifungal bacteria against Botrytis cinerea.The results showed that among 58 strains,strain ZSY-1 had more significantly antifungal activity against  B.cinerea than other strains and had more than 75% antifungal activity against B.cinerea in indoor and field trials.Although the colonization characteristics of strain FG-6 in tomato rhizosphere (1.76×10 6cfu/g),root system(1.54×10 6cfu/g)and leaf(0.87×10 6cfu/g) were significantly better than strain ZSY-1(rhizosphere:1.67×10 6cfu/g;root system:1.46×10 6cfu/g;leaf:0.64×10 6cfu/g),but its field control effect was only about 30%,which was significantly lower than strain ZSY-1. Strain ZSY-1 was identified as Ba cillus velezensis based on morphology,physiological and biochemical characteristics,16S rRNA, gyrA,and gyrB genes.The above results determined that strain ZSY-1 might be an excellent candidate strain against B.cinerea for the development of biological agents. Related Articles | Metrics Select Identification and Optimization of Fermentation Conditions of an Antagonistic Endophytic Fungus from Mountain-cultivated Ginseng ZHOU Chunyuan, XU Shiquan, YAN Meixia, CUI Lili, HUA Shuang, WANG Yingping Journal of Henan Agricultural Sciences    2020, 49 (2): 104-110.   DOI: 10.15933/j.cnki.1004-3268.2020.02.013 Abstract （67）      PDF （1667KB）（166）       Knowledge map    Save The antagonistic endophytic fungi were isolated and screened from healthy mountain-cultivated ginseng leaves,to provide good strains for the biological control of ginseng black disease.Tissue isolation method was used to isolate the endophytic fungi.The antagonistic fungi was identified based on morphological characteristics and phylogenetic analyses of 18S rDNA.The single factor experiment and orthogonal experiment were adopted to optimize the liquid fermentation medium and conditions.The results showed that endophytic fungi were isolated from healthy mountain-cultivated ginseng leaves.Among them,strain FS-01 was found to have strong antagonistic activity against Alternaria panax.Strain FS-01 was identified as Chaetomium globosum.The optimal medium was composed of 1.50% starch,1.00% yeast extract powder,0.05% dipotassium phosphate,0.10% magnesium sulfate and the optimal culture conditions were inoculation size of 6.0% and cultivated for 5 d at 30℃ with initial pH of 7.0.Strain FS-01 has strong antagonistic activity against Alternaria panax,and could be a biocontrol strain for developing against ginseng black disease. 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