基于毒性相关基因序列的稻瘟病菌群体遗传多样性分析  

Analysis of genetic diversity among populations of rice blast fungus based on the fingerprint of virulence gene

作　　者：邓其明[1] 颜学海 何建美[1] 邓元宝 韩冬[1] 杨阳[1] 李彬[1] 朱军[1] 李平[1] 

机构地区：[1]四川农业大学水稻研究所,温江611130

出　　处：《植物病理学报》2016年第1期91-102,共12页Acta Phytopathologica Sinica

基　　金：国家高技术研究发展计划(863计划)项目(2011AA10A101)

摘　　要：选用16对毒性相关基因特异性引物对四川和重庆9个县(市)分离到的200个稻瘟病菌单孢菌株进行PCR扩增,并采用最长距离法进行聚类分析,结果显示各引物均能扩增出其目的条带,多态位点百分率(P)高达93.75%,扩增频率差异较大;200个菌株可归为70个不同的单元型,其中单元型SCH13为优势单元型;在0.86遗传相似水平上,200个菌株可划分为27个遗传宗谱,包括1个优势宗谱,3个亚优势宗谱,14个次要宗谱,9个小宗谱,层次丰富;在群体平均水平上,病菌群体具有丰富的遗传多样性(H=0.324 4,I=0.484 2),且群体间差异较大;9个种群在遗传距离为0.05水平上可分为4个类群,种群遗传谱系与地理区域分布呈一定相关性。同时,该地区的群体存在一定的遗传分化(HT=0.320 0),群体内多样性大于群体间多样性(Hs=0.179 6,Dst=0.140 4),总遗传变异的56.13%存在于群体内(Gst=0.438 7),群体间基因流动性较小(Nm=0.639 6)。本研究揭示了四川和重庆部分区域稻瘟病菌群体遗传结构、遗传多样性及其与地理分布之间的关系,为抗病育种和品种布局奠定了基础。Two hundred single spore isolates of Magnaporthe oryzea from nine counties/cities in Sichuan and Chongqing were amplified with 16 pairs of virulence gene-specific primers. The results showed that the target bands could be clearly amplified with all the primers, and the percentage of polymorphic loci （P） reached 93.75%. Those isolates were classified into 70 different haplotypes and 27 genetic lineages at the genetic similarity coefficient level of 0.86 by cluster analysis. Among the 70 haplotypes, SCH13 was the dominant haplotype. The twenty-seven genetic lineages included 1 advantage lineage, 3 subdominant lineages, 14 secondary lineages and 9 minor lineages. At population level, it was showed that there existed rich genetic diversity among 200 isolates, and the diversity： existed among fungal populations from different geographic regions （H= 0.324 4 ,I= 0.484 2）. The 9 populations were clustered into 4 groups at 0.05 genetic distance level, and the genetic lineages of the populations from different areas are related to their geographic distributions. Meanwhile, certain genetic differentiation existed in the same fungal population. The genetic diversity of within-population was higher than that of among-population （ Hs = 0.179 6, Dst = 0.140 4 ）, and accounted for 56.13% of the total variation existed in within-population （Gst = 0.438 7）. The gene flow was less in within-population （Nm =0.6396）. The study reveals the genetic structure, genetic diversity of M. oryzea populations and the relationship of the geographic distributions and the fungal populations from Sichuan and Chongqing, which could provide the basis for rice blast resistance breeding and rational arrangement of rice varieties in these regions.

关 键 词：稻瘟病菌 致病基因 无毒基因 DNA指纹 遗传多样性 

分 类 号：S435.111.41[农业科学—农业昆虫与害虫防治]