我国部分地区小麦叶锈菌遗传多样性的SSR分析

摘要

小麦叶锈菌(Puccinia triticina)引起的小麦叶锈病是小麦上的重要病害.为了解小麦叶锈菌遗传多样性及其亲缘关系,本研究利用简单重复序列(simple sequence repeat,SSR)标记技术对2009年采自河北、河南、山东、四川4省的小麦叶锈菌株进行SSR分析.小麦叶锈菌的观察等位基因数(Na)为1.75,有效等位基因数(Ne)为1.40,Shannon信息指数(I)为0.35,Nei's基因多样性指数(H)为0.23,多态性百分率为75.29％,其中河北、河南和山东的叶锈菌群体遗传多样性水平高于四川群体.聚类分析表明,在相似系数0.96处4个群体聚为2组,河南、山东及四川群体聚为一组,河北群体自成一组,其中河南和山东群体亲缘关系最近.小麦叶锈菌具有一定的遗传变异,群体间遗传变异占总变异的8.93％,群体内遗传变异占总变异的91.07％.小麦叶锈菌群体间每代迁移数Hm为6.10.小麦叶锈菌遗传多样性丰富,群体间遗传相似性较高,亲缘关系与地理分布具有一定相关性.群体内遗传变异是群体遗传变异的主要来源.本研究说明群体间存在广泛的菌源交流,为明确小麦叶锈病流行区系和叶锈菌传播路线提供了基础资料.%Wheat leaf rust, caused by Puccinia triticina, is an important epidemic disease of wheat in China. The objective of this research was to understand the molecular genetic diversity and genetic relationship of P. Triticina populations in China, In the research, all the Chinese P. Triticina samples were collected from Hebei, Henan, Shandong and Sichuan Province in 2009 for analyzing by SSR marker. For the leaf rust populations, the average observed number of alleles (Na) per locus was 1.75, the effective number of alleles (Ne) was 1.40, Shannon's information index (Ⅰ) was 0.35, Nei's gene diversity (H) was 0.23, and percent of polymorphic was 75.29%. The result showed that the populations of P. Triticina were considerably genetic diversified and the genetic diversity level of P. Triticina in Hebei, Henan and Shandong was higher than that in Sichuan. UPGMA cluster analysis showed that 4 populations were clustered into 2 groups at similarity coefficient 0.96, Henan, Shandong and Sichuan clustered in group 2, Hebei clustered in group 1, and the closest genetic relationships were found between Henan and Shandong. Genetic differentiation was investigated by analysis of molecular rnvariance(AMOVA). There were about 8.93% of the total variations among populations and about 91.07% of the total variations within populations. The Nm was 6.10. The result showed that the populations of P. Triticina possessed relatively high levels of genetic diversity. There was high genetic similarity among populations, and the genetic relationships were associated with graphical distribution. The main genetic variation came from the same population. The migration of pathogen among the regions was presented, and this conclusion will help to determine the epidemic regions and dispersal routes of wheat leaf rust.