Abstract:

【Objective】 As Longnan region of Gansu province is one of the largest and most important over-summering areas of Puccinia striiformis f. sp. tritici in China, the objective of this study is to determine the genetic structure of P. striiformis f. sp. tritici populations in this region. 【Method】 Population genetic diversity of the P. striiformis f.sp. tritici population containing 409 isolates collected from 8 different areas in Longnan, Gansu province was investigated with TP-M13-SSR technique. 【Result】 For the Longnan population, the average number of alleles (Na) per locus was 1.95, and the effective number of alleles (Ne) was 1.43. The Nei's gene diversity (H) and Shannon's information index (I) were 0.27 and 0.41, respectively. The genetic diversity of Wudu, Wenxian and Qingcheng populations was much higher than that of Huixian, Chengxian and Xihe populations. Analysis of AMOVA showed that there were about 12.5% of the total variations among the collections, 87.5% of the total variation presented within collections. Gen flow (Nm) was 1.83. 【Conclusion】 The important conclusion is that the populations of P. striifornis f. sp. tritici possessed relatively high levels of genetic diversity but a lower genetic differentiation in Longnan of Gansu. The main genetic variation presented within collections. There is an extensive gene flow and migration of pathogen among the regions in Longnan of Gansu.

Key words: Puccinia striiformis f.sp.trtici, population genetic diversity, SSR marker