EST-SSR based diversity analysis of Phytophthora infestans in different isolates collected from Gansu Province, China

摘要

Effective molecular markers are required to characterize the genetic diversity of plant pathogens. In this study, we used the software SSRIT searched 12,581 Phytophthora infestans ESTs in EST databases. Among these ESTs, there were 388 sequences of containing-SSR, in which 123 trinucleotide repeats are the most abundant type accounting for 31.7% of the total identified. Eleven pairs of primers were designed and synthesized, and genomic DNA of Phytophthora infestans was extracted, with 63 isolates of Phytophthora infestans used for polymerase chain reaction amplification, nine pairs of primers (81.8%) amplified polymorphic SSR bands. The 63 isolates of Phytophthora infestans were divided into 20 genotypes by cluster analysis. The results suggest that using EST-derived SSRs the Phytophthora infestans in Gansu are of rich genetic diversity.