家蚕灰僵病病原的鉴定

家蚕灰僵病(grey muscardine)是一类不常见的真菌病,其病原一直未能确定。从感染灰僵病的家蚕体中分离获得一株棒束孢(Isaria),菌株编号为RCEF197,测定了该菌株的ITS1-5.8S-ITS2 rDNA区域序列,研究了该菌株的菌落和显微形态特征。与一些近似的棒束孢和拟青霉(Paecilomyces)的ITS序列进行比较,该菌株和爪哇棒束孢菌株CBS134.22的相似性为99.8%,在构建的棒束孢属部分种的系统发育树中,该菌株与爪哇棒束孢聚为一类,再结合该菌株具有的淡灰紫色菌落和长椭圆形分生孢子大小等形态学特征,将家蚕灰僵病的病原确定为爪哇棒束孢Isaria javanica。

Pathogen Identification of Grey Muscardine of the Silkworm, Bombyx mori

The grey muscardine of the silkworm is a kind of uncommon mycosis, and its pathogen hasn′t been identified. A Isaria strain, RCEF197, was isolated from a silkworm cadaver died of grey muscardine. The ITS1-5.8S-ITS2 rDNA region from RCEF197 was sequenced, and the colonial and microscopic characters of RCEF197 were investigated. Comparison analysis of the ITS with that of some close species of Isaria and Paecilomyces, it has 99.8% identity to Isaria javanica strain CBS134.22. Phylogenetic tree based on ITS region sequence data from Isaria spp showed that RCEF197 was clustered together with Isaria javanica. Furthermore, combined with the morphological characters, the pathogen of grey muscardine of the silkworm should be identified as Isaria javanica.