Integrative taxonomy reveals three novel pathogens belonging to Coniella, Colletotrichum and Pestalotiopsis on Nekemias grossedentata in China.

Nekemias grossedentata (syn. Ampelopsis grossedentata, vine tea) is an economically important medicinal plant in China, yet the diversity of foliar fungal pathogens remains poorly understood. In this study, three pathogenic fungi were isolated from symptomatic N. grossedentata leaves collected in Enshi Tujia and Miao Autonomous Prefecture, Hubei Province, China. Their taxonomic status was determined using an integrative approach combining morphological characterisation, multi-locus phylogenetic analysis, coalescent species delimitation and SNP-based PCA (SNPs extracted from concatenated multi-locus sequences). The pathogenicity was confirmed by fulfilling Koch's postulates. Three novel species are formally described herein: Coniella ampelopsidis, Colletotrichum enshiense and Pestalotiopsis ampelopsidis. All analyses consistently resolved the three species as independent taxa with highly-supported evolutionary lineages, distinct genetic clustering and significant nucleotide divergence. This study also enriches the inventory of foliar fungal pathogens infecting Nekemias grossedentata and provides a basis for integrated disease management.