稻瘟病生防细菌的筛选及其防效测定  

Screening of biocontrol bacteria against rice blast and determination of their efficacy

作　　者：孙正祥[1,2] 郑通文 毛国庆 刘璐 陈东[1,2] 周燚 SUN Zhengxiang;ZHENG Tongwen;MAO Guoqing;LIU Lu;CHEN Dong;ZHOU Yi(College of Agriculture,Yangtze University,Jingzhou 434025,Hubei;Forewarning and Management of Agricultural and Forestry Pests,Hubei Engineering Technology Center(Yangtze University),Jingzhou 434025,Hubei)

机构地区：[1]长江大学农学院,湖北荆州434025 [2]湖北省农林病虫害预警与调控工程技术研究中心(长江大学),湖北荆州434025

出　　处：《长江大学学报（自然科学版）》2021年第1期115-121,共7页Journal of Yangtze University(Natural Science Edition)

基　　金：国家重点研发计划项目子项目“植物微生态制剂的研制与应用”(2017YFD0201106-08);湖北省大学生创新创业训练计划项目“一株新型生防细菌S17-377抑菌活性物质的分离鉴定”(2019254)。

摘　　要：为筛选得到对稻瘟病有良好防效的拮抗细菌,为稻瘟病的生物防治提供更多的菌源。采用稀释涂布法从对节白蜡(Fraxinus hupehensis Chiu,Shang et Su)及其根际分离细菌,通过平板对峙、离体叶片试验和盆栽试验筛选稻瘟病菌(Magnaporthe grisea)的拮抗菌株,测定其产胞外酶活性,并经16S rDNA序列分析对其进行鉴定。结果显示,从对节白蜡及其根际共分离得到193株细菌,经平板筛选得到7株对稻瘟病菌具有抑制作用的细菌,其抑制率为62.53%~75.47%,其中菌株YZU-S033和YZU-S061对稻瘟病菌的抑制率最高,在离体叶片试验中对稻瘟病的防效较强,分别为81.7%和69.4%。在盆栽试验中,菌株YZU-S033和YZU-S061的菌体悬浮液显著降低了稻瘟病的发病率,减轻了该病害的发病程度,其防效分别可达69.8%和64.0%,与对照药剂(枯草芽孢杆菌可湿性粉剂)的防效相当。这2株拮抗细菌均能产生蛋白酶和纤维素酶,其中YZU-S061还可分泌嗜铁素。经系统发育分析将菌株YZU-S033和YZU-S061均鉴定为贝莱斯芽孢杆菌(Bacillus velezensis)。结果表明菌株YZU-S033和YZU-S061对稻瘟病均具有良好的生防潜力和应用前景。To screen biocontrol bacteria with high efficacy against rice blast,so as to provide more bacterial sources for the biological control of rice blast,bacteria were isolated from the roots and rhizosphere of Fraxinus hupehensis by serial dilution method.The antagonistic strains against Magnaporthe grisea were screened by dual culture,detached leaf assay and pot experiment,and their extracellular enzyme activities were determined.The 16S rDNA sequence analysis was used to identify the bacteria.The results showed that 193 bacterial strains were isolated from F.hupehensis and its rhizosphere,and 7 strains with inhibitory effect on M.grisea were obtained by plate screening.The inhibition rates were 62.53%-75.47%.Among them,strains YZU-S033 and YZU-S061 had the highest inhibition rates on M.grisea,and they showed 81.7%and 69.4%efficacy against rice blast in the detached leaf assay,respectively.In pot experiments,the bacterial suspensions of strains YZU-S033 and YZU-S061 significantly reduced the incidence of rice blast disease and alleviated the disease to an extent that the efficacy could reach 69.8%and 64.0%,respectively,which was comparable to that of the control agent(Bacillus subtilis wettable powder).Both bacteria could produce protease and cellulase,between which YZU-S061 could also secrete siderophores.Strains YZU-S033 and YZU-S061 were both identified as Bacillus velezensis after phylogenetic analysis.This study showed that strains YZU-S033 and YZU-S061 had good biocontrol potential and application prospectsagainst rice blast.

关 键 词：稻瘟病 生防细菌 离体叶片试验 胞外酶 

分 类 号：S535.111.4+1[农业科学—作物学]