黄瓜白粉病的生防细菌筛选及鉴定

Screening and Identification of Bacterial Biocontrol Agents Controlling Cucumber Powdery Mildew

为开发黄瓜白粉病的生防资源,与三七根腐病菌、禾谷镰刀菌和柑橘炭疽病菌进行平板对峙培养,从25株黄瓜根际土细菌和91株烟草内生细菌中筛选出具拮抗功能的菌株;以盆栽试验从拮抗功能菌株中筛选能够防治黄瓜白粉病的生防菌株;用PCR扩增生防菌株的gyr B基因,结合菌株的菌落形态和部分生理生化特征,确定生防菌株分类地位。结果表明,在116株对峙培养细菌中,18株对三七根腐病菌、禾谷镰刀菌和柑橘炭疽病菌有较好拮抗效果。在盆栽试验中,烟草内生菌YN-201490和黄瓜根际菌株WL-1对黄瓜白粉病防效较好,其中YN-201490的1.81×108cfu/m L和WL-1的1.6×108cfu/m L稀释液连续施用3次后的防效分别达64.86%和61.26%。最终YN-201490被鉴定为枯草芽孢杆菌,WL-1被鉴定为解淀粉芽孢杆菌。

In order to utilize bioagent sources to control cucumber powdery mildew,25 strains from cucumberrhizospheric bacteria and 91 endophytic bacterial strains of tobacco were used to screen antagonistic bioagentsby dual culture experiment with the indicator pathogens Fusarium solani,F.graminearum and Colletotrichum gloeosporioides.The bioagents controlling cucumber powdery mildew were searched from the antagonisticbioagents through pot culture test.The effective bioagents were identified based on colony phenotype,physiological and biochemical characteristics and gyr B gene sequence by PCR.The results showed that 18 bioagents were screened from the 116 bacterial strains and could inhibit the indicators effectively.Theendophytic YN-201490 and rhizospheric WL-1 could control the disease with efficiency of 64.86% and61.26% in the pot culture test when they were sprayed three times with 1.81×10^8cfu/mL.YN-201490 andWL-1 were identified as Bacillus subtilis and B.amyloliquefaciens,respectively.