中国香菇主栽品种遗传多样性的SSR分析及指纹图谱构建

摘要

[目的]香菇Lentinulaedodes)是世界第二大食用菌,研究我国现有栽培种群体的遗传多样性和遗传构成以及准确鉴定品种是新品种开发和产业健康发展的基础.[方法]采用多态性的SSR (Simple sequence repeat)分子标记对中国历年来使用主栽品种进行遗传多样性及群体结构分析,比较其谱系来源,解析中国主栽品种的群体多样性构成,并构建指纹图谱用于品种鉴定.[结果]24对多态性SSR引物对51份香菇菌株都具有多态性.聚类分析在相似系数0.69处可将栽培种群体分为4个类群,野生种驯化或参与杂交获得的菌株位于类群Ⅲ和Ⅳ,其他菌株位于另外两个类群Ⅰ和Ⅱ.群体结构分析可将栽培群体分为6个遗传构成,显示L808、L135等代表性菌株在各自的构成中参与了其他菌株的选育过程,解释了以其为亲本的部分品种的谱系来源.依据筛选出的9对条带清晰的SSR引物组合构建了多位点SSR指纹图谱,可对45个香菇商业菌种进行辨识.[结论]我国香菇主栽品种亲缘关系较近,育种多围绕L808、L135、9015等核心代表性品种进行,本研究可为选育具有自主知识产权、适应不同栽培模式的新品种提供依据;指纹图谱的构建也能为香菇品种的准确鉴定提供保证.%[Objective] Xianggu (Lentinulaedodes) is the second biggest edible fungi in the world.Genetic diversity and population structure analysis and reliable identification of strains are prerequisites for new cultivar breeding and the sustainable development of Xianggu mushroom industry.[Methods] Using polymorphic SSR markers to analysis the genetic diversity and population structure of the major cultivars in China,comparing their genetic pedigree and constructing the fingerprint profiles that can be used for varietal identification.[Results] In this study,51 strains were identified with SSR markers including 24 pairs of primers and their polymorphism was 100％.According to the chustering analysis,experimental population could be divided into four clusters at the similarity of 0.69.Wild strains or cultivars derived from wild strains in cluster Ⅲ and Ⅳ,and other hybrid cultivars in cluster Ⅰ and Ⅱ.The cultivar population can be divided into 6 genetics compositions according to the population structure analysis.Showing that several core strains are involved in others' breeding procedure such as L808、L135,and can explain the pedigree of the cultivars used them as parents.9SSR primer pairs delineated 45 of the cultivars based on the unique multilocus SSR fingerprint profiles.[Conclusion] The results indicated a close genetic relationship of cultivars in China,and the breeding research was always focus on several core strains such as L808、L135、9015.This research offered some references to the genetic breeding that has our own intellectual property and can adjust different cultivation mode.The fingerprint profiles could also provide safeguards for the reliable identification of Xianggu strains.