Genetic Diversity and Phylogenetic Relationships among Phytophthora capsici Isolates from Guizhou Province by RAPD

Ten random primers with clear amplification profile,significant and stable main band were screened from RAPD( Random Amplified Polymorphic DNAs) primers to analyze the genetic diversity among eight Phytophthora capsici isolates from Huaxi District,Wudang District and Kaiyang County of Guiyang City,and Zunyi County,Suiyang County and Luodian County of Zunyi City in Guizhou Province. A total of 70 DNA fingerprints were obtained,including 57 polymorphic bands,with a polymorphic percentage of 81. 43%,suggesting abundant genetic diversity among experimental Phytophthora capsici isolates. According to the amplified DNA fingerprint profiles,using genetic similarity coefficient 0. 5 as the threshold,experimental Phytophthora capsici isolates were clustered into three genetic categories by UPGMA cluster analysis. The analysis result indicated that there was no direct correlation between the genetic similarity and cultivation areas of various Phytophthora capsici isolates.