黄瓜立枯病高效拮抗菌的筛选与鉴定

为获得对黄瓜立枯病具有显著防效的优良菌株,以从果蔬体内、根际土壤等多生境中分离的100株细菌为出发菌株,采用平板对峙法和拌土法对100株供试菌株进行初筛和复筛。初筛得到8株能显著抑制立枯丝核菌(Rhizoctonia solani)的菌株(抑菌带直径D0.60cm);复筛进一步分析表明,其中3株菌能够显著促进黄瓜幼苗的生长和高效防治苗期立枯病害,与对照相比,黄瓜幼苗壮苗指数分别增加16.22%(60)、13.48%(K13)和43.04%(Z84),相对防效分别达67.53%(60)、59.42%(K13)和77.27%(Z84);通过形态观察、生理生化试验及16SrDNA同源性序列对比分析,将60、K13和Z84菌株鉴定为解淀粉芽孢杆菌(Bacillus amyloliquefaciens),可为蔬菜苗期高效微生物制剂的开发提供微生物资源。

Screening and identifying antagonistic bacteria against Rhizoctonia solani on damping-off disease of cucumber

In the study,100 bacterial strains from some vegetables or rhizosphere soil were used to screen antagonistic bacteria against Rhizoctonia solani by the dual culture method.Eight strains of bacterial antagonists were isolated and their inhabiting zone against R.solani was more than 0.60 cm.Through application of cucumber seedlings,three of the eight antagonists could increasingly promote the growth of cucumber seedlings.Seedling indices were 16.22% (60),13.48%(K13)and 43.04% (Z84)respectively compared to the control seedlings.Meanwhile,three strains (60,K13 and Z84) of the six strains could increasingly prevent the cucumber damping-off disease with the control efficiency of 67.53%,59.42% and 77.27% respectively.According to the characteristics of morphology,the physiology and biochemistry test and the comparison of 16S rDNA sequence,three strains(60,K13 and Z84) were identified as Bacillus amyloliquefaciens. The three strains of antagonistic bacteria can be used as a biological control agency to control the cucumber damping-off disease.