Genetic Diversity of Gray Leaf Spot Pathogen on Dictamnus dasycarpus in Heilongjiang Province

摘要

To ascertain the genetic diversity of gray leaf spot pathogen on Dictamnus dasycarpus popoulation in Heilongjiang Province, a total of 57 strains of Paracercospora dictamnicola were isolated and purified from the diseased samples collected from five Chinese herbal medicine planting areas in Heilongjiang Province between the years of 2021 and 2022. Repetitive extragenic palindromic polymerase chain reaction(Rep–PCR) was used to amplify 57 isolates of gray leaf spot pathogen on D. dasycarpus from different regions of Heilongjiang Province. The polymorphic bands amplified by three sets of primers accounted for more than 80%. Cluster analysis results showed that at a similarity coefficient of 0.67, the gray leaf spot pathogen on D. dasycarpus in Heilongjiang Province could be divided into five major genetic groups. Genetic diversity parameter analysis indicated that there were certain differences in genetic richness among the geographic populations of gray leaf spot pathogen on D. dasycarpus from different regions. Analysis of molecular variance(AMOVA) revealed that genetic variation among strains mainly originated within populations. The genetic differentiation and relationships of gray leaf spot pathogen on D. dasycarpus from different geographic regions of Heilongjiang Province indicated that genetic differentiation and kinship among populations were somewhat related to their geographic distance. The greater the geographic distance, the higher the genetic differentiation coefficient, and the lower the genetic uniformity among populations.

关键词

genetic diversity / gray leaf spot / repetitive extragenic palindromic polymerase chain reaction(Rep–PCR) / cluster analysis / analysis of molecular variance