Genetic relationships between Anhui and Heilongjiang populations of Phytophthora sojae assessed by SSR markers
安徽和黑龙江省大豆疫霉群体遗传结构的SSR分析

The genetic diversity of two geographic populations of Phytophthora sojae Kauf. & Gerd. from Anhui and Heilongjiang Provinces was determined using the molecular marker of simple sequence repeats (SSRs). Genetic variation was analyzed for 83 isolates of P. sojae. By using 20 pairs of SSR primers, a total of 109 polymophic bands (alleles) were amplified at an average of 5.5 bands per pair of primers. Genetic similarity analysis showed that there were obvious differences between Helongjiang and Anhui populations. Cluster analysis with an unweighted pair group method revealed that the 83 isolates of P. sojae were clearly separated into seven clustering groups (genotypes) at a level of 80% similarity. We also found that isolates from Heilongjiang had lower genotypic diversity than those of Anhui. In addition, three particular P. sojae genotypes were only found in Anhui population and two particular genotypes were only found in Heilongjiang population. In conclusion, the results in this study do not support the hypothesis that P. sojae in Anhui has immigrated from Heilongjiang.