Abstract
Tea plant is one of the most important commercial crops worldwide. The Didymellaceae fungi can cause leaf blight disease of tea plant. In this study, 240 isolates were isolated from tea plant leaves of 10 provinces in China. Combined with multi-locus (ITS, LSU, RPB2 and TUB2) phylogenetic analysis and morphological characteristics, these isolates were identified as 25 species of six genera in Didymellaceae, including 19 known species Didymella coffeae-arabicae, D. pomorum, D. segeticola, D. sinensis, Epicoccum catenisporum, E. dendrobii, E. draconis, E. italicum, E. latusicollum, E. mackenziei, E. oryzae, E. poaceicola, E. rosae, E. sorghinum, E. tobaicum, Neoascochyta mortariensis, Paraboeremia litseae, Remotididymella anemophila and Stagonosporopsis caricae, of which 15 species were new record species and six novel species, named D. yunnanensis, E. anhuiense, E. jingdongense, E. puerense, N. yunnanensis and N. zhejiangensis. Amongst all isolates, D. segeticola was the most dominant species. Pathogenicity tests on tea plant leaves showed that E. anhuiense had the strongest virulence, while E. puerense had the weakest virulence. Besides, D. pomorum, D. yunnanensis, E. dendrobii, E. italicum, E. jingdongense, E. mackenziei, E. oryzae, E. rosae, E. tobaicum, N. mortariensis, N. yunnanensis, N. zhejiangensis and R. anemophila were non-pathogenic to the tea plant.