中国小麦条锈菌流行小种的RAPD分析

 用随机扩增多态性DNA（Random amplified polymorphic DNA，RAPD）技术对中国小麦条锈菌（Puccinia striiformis f.sp.tritici）流行小种的11个模式分离系（CY17，CY19，CY21，CY22，CY23，CY25，CY26, CY27，CY28，CY29，水源11-1）以及5个分属于两个新发现小种CY30和CY31的分离系进行了基因组DNA多态性分析。用17个10-核苷酸随机引物共获得114个RAPD标记，其中75.4%表现多态性。选取共中的58个RAPD标记通过系统聚类分析确定了供试分离系间的亲缘关系，并与以毒性标记为基础确定的分离系间的演化关系进行了比较。结果表明，DNA多态性与毒性多态性之间没有相关性。利用RAPD标记检测到了小种间以及小种内的遗传变异，有些引物扩增到了分离系特异的RAPD特征图谱。与其它基因组多态性分析技术相比，RAPD分析可为小麦条锈菌的遗传分析提供大量的分子标记，且具有技术操作简单、快速、安全以及仅需微量的模板DNA等优点，对该活体营养病菌的群体遗传结构分析极 具潜力。

RAPD ANALYSIS OF EPIDEMIC RACES OF PUCCINIA STRIIFORMIS f.sp.TRITICI IN CHINA

Chinese reference isolates of predominant races of Puccinia striiformis f.sp. tritici, the causal agent of wheat stripe rust disease, were examined for genetic variation with the random amplified polymorphic DNA (RAPD) assay. Random decamer primers were used to amplify DNA isolated from 11 reference isolates of the 11 predominant races ,CY17,CY19,CY21,CY22,CY23, CY25,CY26,CY27,CY28,CY29,and Shuiyuan 11-1,respectively,and 5 isolates sampled form geographically separated regions belonging to two newly identified pathotypes (races),CY30 and CY31.of 114 RAPD loci amplified with 17 primers,75.4% were polymorphic. Genetic relatedness among the 16 reference isolates was determined by hierarchical cluster analysis of 58 selected RAPD loci generated by 17 random decamer primers. A lack of correlation between the virulence and RAPD dissimilarity matrices was observed, indicating the independence of DNA polymorphism from virulence diversity. DNA polymorphism was detected among isolates of different as well as of single races. RAPD patterns generated by some primers enabled us to resolve distinctly all the isolates tested. Compared with other attempts to develop sufficient markers for genetic analysis of P. striiformis f. sp. tritici, RAPD procedure is technically simple, rapid, and reproducible, and has potential application for stringent genetic characterization of the population structure of this obligata pathogen.