拮抗链霉菌26B的筛选及其在不同含水量土壤中对白菜软腐病的防病效果  

Screening of Antagonistic Streptomyces 26B and Its Efficacy on the control of Soft Rot Disease of Chinese Cabbage in Soil with Different Water Content

作　　者：张世昌 张宇璐 谭晓东 郭荣君[2] 李世东[2] 罗明[1] ZHANG Shichang;ZHANG Yulu;TAN Xiaodong;GUO Rongjun;LI Shidong;LUO Ming(College of Agriculture,Xinjiang Agricultural University,Urumqi 830052,China;Institute of Plant Protection,Chinese Academy of Agricultural Sciences,Beijing 100193,China;Beijing Cultivated Land Construction and Protection Center,Beijing 100101,China)

机构地区：[1]新疆农业大学农学院,乌鲁木齐830052 [2]中国农业科学院植物保护研究所,北京100193 [3]北京市耕地建设保护中心,北京100101

出　　处：《中国生物防治学报》2023年第1期157-166,共10页Chinese Journal of Biological Control

基　　金：现代农业产业技术体系项目(CARS-23-C04);广西重大研发计划(桂科AB21220030)。

摘　　要：为挖掘防治白菜软腐病的生防菌,本研究采用牛津杯法从38株白菜根际放线菌中筛选到一株拮抗放线菌26B,通过形态学观察和16S rRNA基因序列分析将菌株26B初步鉴定为链霉菌。该菌除菌发酵滤液对供试的白菜软腐病菌Pectobacterium carotovorum subsp.brasiliensis BC1及3种马铃薯黑胫病菌均表现较高的抑菌活性,其中对白菜软腐病菌抑菌直径达到23.97mm。萌发试验表明,白菜种子经26B除菌发酵滤液浸种后发芽势、发芽指数、根长及鲜重显著增加。采用浸根法测定菌株26B除菌发酵滤液对软腐病菌荧光标记菌株BC1-gfp在白菜根部定殖量的影响,浸根处理后48h,白菜根上BC1-gfp的数量达到2.3×109CFU/g;未从26B除菌发酵滤液与BC1-gfp菌悬液混和处理(体积比10%)的白菜根上检测到病原菌。盆栽防病试验结果表明,在含水量为14%和20%的土壤中,菌株26B除菌发酵滤液对白菜软腐病的防效分别达96.0%和89.8%。上述结果表明,链霉菌26B是一株具有潜在开发应用价值的生防菌株,将链霉菌26B应用与土壤水分管理相结合可进一步提高其防病效果。The purpose of this study is to obtain the biocontrol bacteria to control the soft rot disease of Chinese cabbage.An antagonistic strain 26B was screened from 38 actinomycete strains isolated from the rhizosphere of Chinese cabbage by Oxford cup method.Strain 26B was identified as Streptomyces based on its morphological characteristics and its 16S rRNA gene sequence analyses.The cell free fermentation filtrate of strain 26B showed high antibacterial activity against Pectobacterium carotovorum subsp.brasiliensis BC1 and three casual bacteria of potato blackleg disease,and the antibacterial diameter against BC1 reached 23.97 mm.The germination assay by seed-soaking showed that the cell free fermentation filtrate of strain 26B significantly promoted the germination potential,germination index,root length and fresh weight of Chinese cabbage seeds.Effects of cell free fermentation filtrate of strain 26B on the inhibition of BC1-gfp colonized on the Chinese cabbage roots was examined by root-dipping method.The results showed that the number of BCl-gfp on cabbage roots reached 2.3×109 CFU/g after 48 hours' incubation in the treatment with BCl-gfp suspension,while no BCl-gfp was detected on the cabbage roots treated with the premixed mixture of BCl-gfp suspension and sterilized fermentation filtrate of strain 26B at a volume ratio of 10%.The bioassay test in potting soil showed that the efficacy of cell free fermentation filtrate of strain 26B on the control of soft rot disease reached 96.0% and 89.8%,respectively,in soil with water content of 14% and 20%.The above results indicated that Streptomyces 26B has great potential to be applied as a biocontrol strain,and its biocontrol efficacy can be improved through coordinately management of soil water content.

关 键 词：白菜软腐病菌 链霉菌 16S rRNA基因 抑菌活性 生物防治 

分 类 号：S476[农业科学—农业昆虫与害虫防治]