中国东部栗疫病菌dsRNA群体的多样性

Diversity of the dsRNA population of Cryphonectria parasitica from eastern China

采用生物学测定和凝胶电泳的方法,对中国东部栗疫病菌(Cryphonectria parasitica)的dsRNA病毒进行了研究。根据电泳图谱,中国东部栗疫病菌的dsRNA病毒可以分为5种类型,其中类型Ⅰ只具有一个12.7 kb的条带,占大多数;类型Ⅱ有两条带,一条 12.7 kb,另一条 5.2 kb左右,只有一个菌株354;类型Ⅲ则除了12.7 kb的条带外,还有3条小于2 kb的小片段,有238和250两个菌株;dsRNA属于类型Ⅳ的为269和344两个菌株,它只含有两个1.8-3.1 kb的小片段;dsRNA类型V只有一个菌株 280,除了一条 12.7 kb分子外,还有 4条 2.6-3.3 kb的小片段。含有dsRNA的菌株培养性状多样,根据菌落特征,栗疫病菌可以划分为5种培养类型,但菌株的培养类型与dsRNA的类型间没有对应的关系。毒力测定表明含有dsRNA病毒的供试菌株大多属于低毒力类型。

Fourty-one dsRNA viruses of Cryphonectria parasitica isolates from eastern China were divided into five types on the basis of gel electrophoresis patterns. Type Ⅰ contained only one segment of 12.7 kb, accounting for majority of the dsRNA viruses. Type Ⅱ had another segment about 5.2 kb besides the seg- ment of 12.7 kb, and was only found in the pathogen isolate 354. Type Ⅲ possessed the 12.7 kb seg- ment and other three small ones shorter than 2 kb, which was detected from the two isolates 238 and 250. Type Ⅳ was separated from pathogen isolates 269 and 344, which contained only two small dsRNA seg- ments about 1.8 - 3.1 kb. Type Ⅴ, including four small dsRNA segments about 2.6 - 3.3 kb and the 12.7 kb one, was only extracted from the isolate 280. The cultural characters of all these tested isolates, whether or not including dsRNA viruses, were diverse and could be also divided into five cultural types. The cultural type of C. parasitica isolate is not consistent with the type of dsRNA virus and virulence test results showed that most of the tested isolates containing dsRNA viruses were hypovirulent.