Abstract: Windflower leaf spot is a newly reported leaf disease in China, and becomes very serious in the protected field of windflower (Pulsitilla chinensis) in Liaoning Province. In this study, a random amplified polymorphic DNA (RAPD) analysis was made on the 25 Ascochyta anemones isolates from 5 main P. chinensis production areas in the Province and 5 Ascochyta spp. isolates presented by the Chinese Academy of Agricultural Sciences. A total of 108 polymorphic DNA bands sized 200-2000 bp were obtained by using 11 random primers. The NTSYS cluster analysis showed that the genetic similarity coefficient of the 30 Ascochyta isolates was 0.56-0.98, and these isolates could be divided into 4 genetic groups when the similarity coefficient was 0.62, suggesting that the pathogens of windflower leaf spot in the Province had rich genetic diversity. There existed definite correlations between the RAPD clustering groups and their geographic distribution, and an obvious genetic difference among the isolates from different host sources.

Key words: Ascochyta anemones, genetic diversity, RAPD, Ascochyta spp.