真姬菇栽培菌株的ITS和SSR分析

ITS and SSR analyses of cultured Hypsizygus marmoreus strains

采用ITS和SSR分子标记技术,对27个真姬菇菌株进行遗传分析。通过内转录间隔区(ITS)区域测定和比较分析,结果显示:供试菌株ITS序列长度为594 bp,与GenBank上登录的真姬菇菌株ITS序列相似度为99%以上,在种的水平上证明供试菌株为真姬菇。利用简单重复序列(SSR)标记技术和转移扩增技术,根据香菇、糙皮侧耳、灰盖鬼伞基因组序列设计引物,对真姬菇供试菌株基因组DNA进行扩增。从54对引物中筛选出23对能够扩增出稳定带型且菌株之间带型差异明显的SSR引物。利用23对引物对全部供试菌株进行扩增,共扩增133条条带,其中多态性条带为108条,多态性比率达到81.2%。UPGMA聚类分析结果表明:大部分常规栽培菌株和工厂化栽培菌株聚在不同组,说明两者之间的遗传背景存在明显差异。根据获得菌株的特有SSR标记分析表明:利用7对引物可以将工厂化栽培菌株区分开,其中2个工厂化栽培菌株各自具有1条特异条带,其他工厂化栽培菌株均可通过引物组合法区分开。

The 27 cultured strains of H. marrnoreus, including 21 conventionally cultured and 6 factory-cultured strains,were genetically analysed by internal transcribed spacer（ITS）and short sequence repeats（SSR）marker. The determination and comparative analysis of the 27 strains＇ITS regions indicated that their ITS sequences were 594 bp long and the amount of similarity in ITS sequence was above 99% between the tested strains and the H. marmoreus strains registered in GenBank,meaning that the tested strains were of H. marmoreus species. SSR primers were designed according to publicly available sequences of Lentinula edodes, Pleurotus ostreatus and Coprinus cinereus, and 23 out of 54 pairs of SSR primers were selected according to the stability and difference of amplification bands. All the tested strains were amplified with the selected 23 pairs of primers and a total of 108 polymorphic bands were obtained. The cluster analysis by unweighted pair group method for arithmetic averages （UPGMA）showed that most of the conventionally cultured strains clustered in one group and most of the factory-cultured strains in another group, indicating that there was sensible difference in genetic background between them. The SSR analysis indicated that the factory-cultured strains could be differentiated with 7 pairs of primers,two of them each had a specific band and the others could be differentiated by primer combination method.