Characterization of Botryosphaeria dothidea, the causal agent of grapevine canker in China

Grapevine canker caused by Botryosphaeriaceae is currently one of most important trunk diseases in the world. This study identified one of the pathogens-B. dothidea that causes grapevine canker in most grapevine growing areas of China and verified its pathogenicity and geographical distribution. In total, 320 grapevine canker sympotoms samples were collected from 17 provinces between 2009 and 2011, and 4261 isolates were isolated from diseased samples. Among these, 1172 isolates purified from 150 samples were identified as B. dothidea by morphological and molecular characterizations. Three representative isolates were used to determine both optimal temperature and optimal nutrition medium for growth and germination. Pathogenicity of B. dothidea was determined in 25 grapevine cultivars. Pathogenicity results showed that most of the main grapevine cultivars growing in China are susceptible to the pathogen.