Population Genetic Structures of Puccinia striiformis f. sp. tritici in Yunnan and Guizhou Province

In order to infer the major migration direction of Puccinia striiformis f. sp. tritici (Pst) between Yunnan and Guizhou populations, amplified fragment length polymorphism (AFLP) was used to analyze population genetic diversity of 71 Pst isolates showing different AFLP genotypes. Among these Pst isolates, 39 isolates were collected from Yunnan Province and 32 from Guizhou Province. There were 32.3% isolates shared AFLP genotypes between Yunnan and Guizhou Pst populations. Only 7% genetic differentiation was observed between the two populations by AMOVA. The most parsimonious tree length test led to rejection of the null hypothesis of free recombination between Yunnan and Guizhou populations. The results indicated that low recombination events and strong gene flow existed between Yunnan and Guizhou populations.