不同地区辣椒疫霉致病力分化及其DNA多态性分析

Pathogenicity Differentiation and DNA Polymorphism of Phytophthora Capsici from Different Areas in China

从山东、湖北、广东、浙江、云南、重庆和湖南7个不同省份采集辣椒疫病病株和病土,经分离纯化获得31株辣椒疫霉菌(Phytophthora capsici)菌株,利用浸根法进行致病力测定,并从100个RAPD随机引物中选出多态扩增性强的14个引物用于对其全基因组DNA的RAPD分析。结果表明,31个菌株具有明显的致病力差异,并有非致病、弱致病、强致病的分化。利用RAPD分子标记方法对受试31个菌株的基因组进行扩增,并用UPGMA软件对受试菌株间的遗传距离进行聚类分析构建系统树状图。结果显示,不同致病力分化的辣椒疫霉具有丰富的遗传多样性,遗传聚类组的划分与菌株的致病力没有显著的相关性。由此说明,来自不同地区的辣椒疫霉的DNA存在较高的遗传多样性,但与其致病力无直接的相关性。

The pathogenicity of 31 isolates of Phytophthora capsici from Shandong,Hubei,Guangdong,Zhejiang,Yunnan,Chongqing and Hunan was identified by soaking root in spore suspension.And the genetic diversity of 31 isolates of P.capsici was analysed by RAPD with 14 primers selected from 100 random primers.The results showed an obvious diversity of pathogenicity,which varied from nonpathogenicity to weak pathpgenicity and to strong pathogenicity.The genetic distance and the genetic relationships of the accessions were reconstructed by use of UPGMA cluster analysis.The result of the RAPD fingerprints showed that the polymorphism existed among isolates with different pathogenicity.And division of isolates was not related to their different pathogenicity.In general,it was concluded that there existed genetic diversity within the 31 isolates of P.capsici,but that there was not relationship between differentiation of pathogenicity and DNA polymorphism.