Identification and Observation of Infection Processes of Colletotrichum Species Associated with Persimmon Anthracnose in Guangxi, China

Abstract

Persimmon originated from China where it has a long cultivation history. Anthracnose fruit rot and leaf blight caused by Colletotrichum species are major diseases of persimmon in China and cause severe economic losses. To determine the species causing anthracnose of persimmon in Guilin, Guangxi province, diseased samples were collected from the four local counties: Gongcheng, Yangshuo, Pingle, and Lipu. Seventy-five isolates were obtained from persimmon samples with anthracnose symptoms and had similar morphological characteristics. Isolates were identified using a BLAST search and phylogenetic analysis of the internal transcribed spacer region, glyceraldehyde -3-phosphate dehydrogenase, partial actin, β-tubulin, chitin synthase genomic regions, Apn2-Mat1-2 intergenic spacer partial mating type gene and calmodulin genes. Five species: C. fructicola, C. horii, C. karsti, C. cliviicola and C. siamense, accounted for 54.7%, 25.3%, 12.0%, 5.3% and 2.7%, respectively, of the total isolates. All five Colletotrichum species were pathogenic on attached leaves and detached fruits of persimmon (cv. Gongcheng Yueshi) in pathogenicity assays. The infection processes of the five Colletotrichum species were observed on persimmon leaves using light microscopy. Conidia of C. fructicola germinated at 12 hours post inoculation (hpi), while quickly formed acervuli at 6 days post inoculation (dpi) and showed the most aggressive. By contrast, conidia of C. cliviicola germinated at 3 hpi, but produced the acervuli at 8 dpi, and showed the least aggressive. This is the first description of C. fructicola, C. cliviicola and C. siamense as causal agents of persimmon anthracnose in Guangxi province, China.