兰花茎腐病拮抗菌HJ-5的筛选和生防潜力评估  

Isolation and Evaluation of the Antagonistic Bacterium HJ-5 against Orchid Stem Rot Disease

作　　者：吕昂 王成 汤亚芳 王立华[1] 姜益泉[1] LÜ Ang;WANG Cheng;TANG Yafang;WANG Lihua;JIANG Yiquan(School of Life Science and Technology,Hubei Engineering University/Hubei Key Laboratory of Quality Control of Characteristic Fruits and Vegetables,Xiaogan 432000,China)

机构地区：[1]湖北工程学院生命科学技术学院/特色果蔬质量安全控制湖北省重点实验室,湖北孝感432000

出　　处：《河南农业科学》2021年第8期85-93,共9页Journal of Henan Agricultural Sciences

基　　金：湖北省科技厅项目(2018CFC850)。

摘　　要：为给兰花茎腐病的绿色防控提供新的微生物资源,从湖北省孝感市健康的兰花幼苗根围土壤中分离筛选拮抗菌,并评估其生防潜力。结果表明,分离到8株对尖孢镰刀菌(Fusarium oxysporum)生长具有良好抑制作用的拮抗菌。16S rDNA测序比对和系统发育树构建表明,这8株拮抗菌均为芽孢杆菌属(Bacillus)。其中,巨大芽孢杆菌(B.megaterium)HJ-5在平板对峙中对尖孢镰刀菌具有较好且稳定的拮抗作用,将其无菌发酵液以5%添加到PDA培养基制成的带毒平板,可抑制灰葡萄孢菌(Botrytis cinerea)、炭疽菌(Colletotrichum siamense)、镰刀菌(F.moniliforme,F.oxysporum)、桃褐腐菌(Monilia fructigena)、毛霉菌(Mucor hiemails)、根霉菌(Rhizopus stolonifer)、核盘菌(Sclerotinia sclerotiorum)和白绢菌(Sclerotium rolfsii)的菌丝生长,抑菌率均高于50%。HJ-5无菌发酵液在高温、强酸碱和长时间紫外线照射条件下仍能保持一定的抗真菌活性。此外,在HJ-5的基因组中扩增到了抗菌物质表面活性素、丰原素的生物合成关键基因sfp和fenB。上述结果表明,巨大芽孢杆菌HJ-5对兰花茎腐病具有良好的生防潜力。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‑5 has excellent biocontrol potential against orchid stem rot.

关 键 词：巨大芽孢杆菌 拮抗作用 兰花茎腐病 无菌发酵液 生防潜力 

分 类 号：S436.8[农业科学—农业昆虫与害虫防治]