河南省小麦全蚀病菌的分离及变种类型鉴定

 从河南省10个地市采集的小麦病根样品中分离得到82株病原分离株, 通过形态特征观察、回接致病性测定、以及分子生物学的方法对所分离菌株进行鉴定。其中47个菌株菌丝分支处都形成典型的“∧”状;子囊壳埋生或半埋生, 子囊棍棒状, 子囊孢子线形, 稍弯曲, 无色, 具有5~10个分隔, 大小为68~94 μm×2~4 μm;对82个分离株rDNA-ITS区进行PCR扩增和序列测定, BLAST序列比对结果表明, 47株菌株与小麦全蚀病菌的ITS序列同源性达97%～99%, 据此确定47株菌株为小麦全蚀病菌。应用小麦全蚀病菌4个变种的特异性引物进行PCR扩增都得到禾顶囊壳小麦变种(870 bp)的特异性片段, 鉴定47株菌株均为禾顶囊壳小麦变种 (Gaeumannomyces graminis var.tritici)。

Isolation and variety identification of Gaeumannomyces graminis causing Wheat take-all in Henan Province

Take-all is the most damaging root disease of wheat and the economically important disease in Henan Province. Eighty-two strains were isolated from wheat root samples which collected from 10 cities, Henan Province. The strains were identified by morphological characteristics, pathogenicity determination and molecular identification. The hypha of 47 strains showed “∧” form at branch. The perithecium was produced immerge or semi-immerge, and the mature ascus was clavate. Ascospores were linear and slight curving and the mature ascospore had 5-10 clear membrance and the size was 68-94×2-4 μm.The rDNA-ITS region of 82 strains were amplified by PCR and then sequenced. By BLAST analysis, rDNA ITS of 47 strains revealed 97%-99% nucleotide identity to that of Gaeumannomyces graminis. Specific fragment of Gaeumannomyces graminis var.tritici was 870 bp in length and which was amplified using the specific primers of 4 variants, therefore the 47 strains were identified as Gaeumannomyces graminis var.tritici.