Characterization, Pathogenicity, and Phylogenetic Analyses of Colletotrichum Species Associated with Brown Blight Disease on Camellia sinensis in China

摘要

Brown blight disease caused by Colletotrichum species is a common and serious foliar disease of tea (Camellia sinensis). Fungal isolates from several tea plantations causing typical brown blight symptoms were identified as belonging to the Colletotrichum acutatum species complex and the Colletotrichum gloeosporioides species complex based on morphological characteristics as well as DNA analysis of the internal transcribed spacer (ITS) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Colletotrichum acutatum, a new causal agent associated with C. sinensis, showed high phenotypic and genotypic diversity compared with the more commonly reportedC. gloeosporioides. Phylogenetic analysis derived from individual an combined ITS and GAPDH sequences clearly clustered C. acutatui and C. gloeosporioides into separate species. Pathogenicity tests vali dated that both species were causal agents of tea brown blight diseas and were highly pathogenic to tea leaves. However, the two group of C. gloeosporioides with low levels of variability within their IT! and GAPDH regions differed in their virulence. This study reports fo the first time the characterization of C. acutatum and C. gloeospot ioides causing brown blight disease on tea (Camellia sinensis (L.) 0 Kuntze) in China.