两种PCR方法对木耳属菌株的遗传多样性评价

应用ERIC和RAPD两种PCR方法对木耳属3种29个菌株进行遗传鉴别，其中ERIC方法是首次运用于食用菌的研究领域。在相似系数75％的水平上，ERIC和RAPD分别将供试菌株分为9组和6组。由ERIC所得的聚类图可将黑木耳和毛木耳两个种区分开，而RAPD则不能完全区分两个种，但两种方法得到了一个相似的结果，即琥珀木耳与黑木耳的亲缘关系极其相近。Southern杂交实验进一步证明了ERIC所得到的29个菌株的同源性关系。分析表明，RAPD方法主要在种的水平上进行鉴别，而ERIC则可以在菌株水平上进行鉴别，结果与菌株栽培性状更为一致。研究结果表明ERIC-PCR是一种比RAPD更快捷可靠的分子标记方法，可以替代RAPD应用于木耳属的遗传多样性及遗传分类的研究。

Assessment The Genetic Diversity of Auricularia Strains by Two PCR-Based Typing Methods

Two PCR-based methods, enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) and randomly amplified polymorphic DNA (RAPD), were adopted for differentiating Auricularia strains. Taken the similarity coefficient as 75%, 29 strains of three Auricularia species were grouped into 6 and 9 clusters by RAPD and ERIC, respectively. The dendrogram from ERIC exhibited two distinct parts, one representing A. auricula and the other A. polytricha, but the dendrogram from RAPD failed to clearly distinguish between these two species. However, both methods similarly revealed high homology between A. fuscosuccinea and A. auricula. The homology relationships among the three species obtained from ERIC were validated by Southern hybridization. The analyses showed that RAPD is able to differentiate mainly at the species level, while ERIC is effective at the strain level and therefore more consistent with cultivation characteristics. The results indicate that the method of ERIC-PCR is more rapid and reliable than RAPD, and may substitute for RAPD in research related to the genetic identification and genetic diversity in Auricularia.