Characterization of Colletotrichum siamense causing crown rot of strawberry in Jingzhou, Hubei Province.

Crown rot (Colletotrichum siamense) of strawberry is a severe disease in Jingzhou, Hubei Province, China. Pathogen identification is the basis for disease prevention and resistance breeding. Nearly fifty isolates were achieved from 192 crown rot samples in this study. A number of 21 isolates were characterized as the pathogen of crown rot of strawberry by Koch’s postulates, and they were identified as Colletotrichum spp. by conidia morphology observation. The 21 isolates were divided into three groups based on colony morphology, and SCR-7, SCR-11 and SCR-16 belonged to each group were clustered into one group with C. siamense isolates by phylogenetic analysis of actin, β-Tubulin 2 and calmodulin sequences. In addition, the isolates of C. siamense SCR-7 showed the strongest pathogenicity of the three which caused highest values of lesion length and leaf temperature, and lowest leaf water content, photosynthetic rate, stomatal conductivity and even transpiration rate values. This study contributes to updating the Colletotrichum species associated with strawberry of China. [ABSTRACT FROM AUTHOR]