我国芝麻主产区茎点枯病病原菌生物学特性分析

摘要

在国内首次对我国湖北、河南、安徽、江西等芝麻主产区进行了较大范围的芝麻茎点枯病病原采集和菌株分离,纯化培养得到35个菌株.通过比较病原菌在不同培养基、不同诱孢处理方式、不同诱孢培养条件等,确定适宜培养条件为普通PDA培养基28℃黑暗培养4～5 d切断菌丝,再培养4～5d,建立了一套较成熟的芝麻茎点枯菌株分离培养纯化技术.对35个菌株的菌落、菌核的形态特征进行了系统观察,测定了不同菌株的致病力,并对其rDNAITS区进行了测序,表明均为菜豆壳球孢(Macrophomina phaseolina( Maubl.)Ashby).35个菌株在表型和致病力等方面存在较为明显的差异,为有针对性的开展芝麻茎点枯病的防治奠定了重要基础.%The pathogen causing sesame charcoal rot were collected from the main sesame production areas, including Hubei, Henan, Anhui and Jiangxi provinces, and 35 strains were isolated finally. By comparing different media, treatment and culture methods for inducing spores, the way to culture the pathogen in PDA medium under darkness and 28℃ for 4 -5 days, then cut off the hyphae and culture another 4 -5 days, was suggested as the optimized option. Based on the direct observation of the phenotypes and sequencing of the rDNA-ITS region by the u-niversal primers ITS1 and ITS4, all the pathogens were confirmed to be Macrophomina phaseolina. This study firstly showed systematic evidences that Macrophomina phaseolina causing sesame charcoal rot in China, and many differences were also detected among these strains in morphology and pathogenicity. The results may be helpful for controlling the Macrophomina phaseolina infecting sesame.