Abstract:

The samples were collected from tea leaves showing anthracnose symptoms from 12 different provinces,and the pathogen was isolated and identified by morphological characteristics and multi-locus phylogenetic analysis,along with the pathogenicity tests according to Koch’s postulates. The results showed that a total of 57 isolates were obtained and divided into five types based on the colony morphology and conidia characteristics. Twenty-one representative isolates were selected for further sequencing and phylogenic analysis based on six loci（ITS,TUB2,ACT,CAL,CHS-1 and GAPDH）. The results indicated that the tested isolates all belonged to Colletotrichum gloeosporioides complex,including seven isolates of C. fructicola,eight isolates of C. camelliae,three isolates of C. siamense and three isolates of C. aenigma. The separation frequency of C. camelliae and C. fructicola in tea area was higher. Pathogenicity assays were performed with 21 representative isolates from the four species of Colletotrichum. They were inoculated on the leaves of detached branches of Camellia sinensis‘Shuchazao’ by stabbing method. It was found that 17 isolates could cause necrosis at the inoculation site of tea leaves at two weeks post infection. Pathogenicity variation was observed among the four species when inoculated on‘Shuchazao’,and the isolates of C. camelliae showed strong virulence. In addition,different isolates of the same species displayed variant virulence. Moreover,this is the first report of C. fructicola causing anthracnose disease of Camellia sinensis in Henan Province,China.

Key words: Camellia sinensis, anthracnose disease, identification of pathogenic, phylogenic analysis, pathogenicity