Vegetative Compatibility and Asexual Recombination in Magnaporthe grisea from Jiangsu Province, China

Vegetative compatibility among isolates of different races in Magnaporthe grisea collectedfrom Jiangsu Province and asexual recombination among compatible isolates by anastomosis were tested.Twenty isolates involving seven races from diseased rice plants were paired on polished rice rose bengal mediumand incubated at 25℃ in darkness for 18 days. Among 173 pairings tested, solid hyphai fusion lines formed byanastomosis between 124 pairings, indicated that these isolates were vegetative compatible with each other.The result showed that most M. grisea isolates were vegetative compatible. Furthermore, 17 vegetative com-patible pairings between monoconidial isolates with MBCsIPTr marker and isolates with MBCrIPTs markerwere selected to detect the asexual recombination between the compatible isolates of different races. The asexu-al recombinants with MBCrIPTr marker were detected in single hyphal fragment progenies in thirteen of theseventeen pairings. The percentage of recombinants was about 0.6 - 11.3%. Results showed that vegetative com-patibility was prevailing among isolates of M. grisea in Jiangsu Province in vitro. These results also suggested thatasexual recombination may be an important mechanism for M. grisea to maintain genetic diversity in nature.