Diversity and pathogenicity of Colletotrichum species associated with tea anthracnose in Nyingchi, Xizang, China

Abstract

Tea anthracnose, caused by Colletotrichum species, represents a critical production constraint in tea industry of Xizang, China. However, no systematic study has investigated Colletotrichum species associated with tea anthracnose in this region. In this study, 70 Colletotrichum isolates were obtained from tea leaves collected across nine sampling sites in Nyingchi's three primary production areas. Multilocus phylogenetic analysis and morphological characterization identified five species: C. boninense, C. camelliae, C. jiangxiense, C. fructicola, and C. karsti. Among these, C. camelliae was the most prevalent species in Nyingchi's tea plantations. Pathogenicity assays on the dominant tea cultivar Camellia sinensis ‘Zhonghuang No. 1’ and ‘Fuding-dabaicha’ revealed that C. camelliae and C. jiangxiense exhibited higher virulence. Colletotrichum boninense and C. fructicola exhibited significantly weaker pathogenicity on Camellia sinensis ‘Zhonghuang No. 1’ than on ‘Fuding-dabaicha’. This study provides the first comprehensive identification and pathogenicity evaluation of Colletotrichum species causing tea anthracnose in Xizang's main tea plantations, offering critical insights for regional disease diagnosis and management.