Morphological characteristics and genetic diversity of Colletotrichum horii infecting persimmon tree in China

Abstract

Anthracnose is the most devastating disease affecting persimmon (Diospyros kaki Thunb.) cultivars in China, and is caused by the pathogen recently identified as Colletotrichum horii. In this study, the symptoms of anthracnose in persimmon fruits and trees in China, and the morphological characteristics of C. horii, were observed and recorded. Thirty simple sequence repeat (SSR) markers for C. horii were developed from the whole genome of the closely related species C. gloeosporioides, which is available from the GenBank database. After screening 30 combinations of primer pairs, six SSR markers were selected to amplify the genomic DNA of 23 isolates, to assess the degree of polymorphism and the reproducibility of the SSR markers. A total of 164 discernible bands were obtained when visualizing the amplicons by electrophoresis, 156 of which showed polymorphism. A dendrogram was constructed with FreeTree software (ver. 0.9.1.50) and the similarity coefficients ranged from 0.58–0.98. The result indicated there was genetic diversity in the C. horii population in China. There was an obvious correlation between the cluster groups and the sites from which the samples were isolated. The results of this study will facilitate a more detailed understanding of the population structure of C. horii in China.