Colletotrichum chinense sp. nov. from Yucca gloriosa and C. quercicola sp. nov. from Quercus variabilis in China

Abstract

Colletotrichum is an important plant pathogenic genus causing anthracnose on a wide range of host plants. During 2019 and 2021, Colletotrichum isolates were obtained during surveys of anthracnose on garden plants in China. Multi-gene phylogenetic analyses of internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (gapdh), chitin synthase 1 (chs-1), actin (act) and beta-tubulin (tub2) sequences coupled with morphological evidence support the introduction of two novel species namely Colletotrichum chinense sp. nov. from Yucca gloriosa in Beijing and C. quercicola sp. nov. from Quercus variabilis in Shaanxi Province. Phylogenetic inference revealed that two isolates of C. chinense belonged to the agaves species complex and were closely related to C. agaves, and differed from the other species within this species complex by shorter conidia and the host association. Molecular identification showed that two isolates of C. quercicola formed a highly supported lineage close to C. tanaceti in the destructivum species complex, which could be distinguished from C. tanaceti by straighter conidia. In pathogenicity tests, yellow spots and orange conidial masses displayed on the inoculated Y. gloriosa leaves and brown spots appeared on the inoculated Q. variabilis leaves. In addition, C. chinense and C. quercicola were re-isolated from spots of the tested leaves of Y. gloriosa and Q. variabilis.