Morphology, Phylogeny, and Pathogenicity of Colletotrichum Species Causing Anthracnose in Camellia japonica in China

Abstract

Camellia japonica is a renowned flower and an influential plant in Chinese urban landscaping. However, Colletotrichum, one of the world’s most commercially important phytopathogenic genera that causes anthracnose on a wide range of plant species, have annually caused significant economic losses to Ca. japonica. In this study, 115 strains were isolated from Ca. japonica leaves with typical symptoms from the provinces of Hunan, Jiangxi, Hainan, Guangxi, Hubei, Chongqing, Guizhou, and Shanxi. They were then subjected to pathogen identification and using method of morphology combined with ApMat gene sequence analysis, along with the pathogenicity tests based on Koch’s postulates. The 115 strains were identified as C. gloeosporioides, C. fructicola, C. siamense, C. camelliae or C. aeschynomenes. Pathogenicity tests revealed that all species produced brown lesions on healthy Ca. japonica leaves, indicating significant virulence. Furthermore, C. fructicola had the broadest distribution and the highest isolation rate., Most importantly, this is the first report in China of C. aeschynomenes causing the anthracnose disease in Ca. japonica.