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

摘要

Vegetative compatibility among isolates of different races in Magnaporthe grisea collected from 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 medium and incubated at 25℃ in darkness for 18 days. Among 173 pairings tested, solid hyphal fusion lines formed by anastomosis 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 compatible pairings between monoconidial isolates with MBC~sIPT~r marker and isolates with MBC~rIPT~s marker were selected to detect the asexual recombination between the compatible isolates of different races. The asexual recombinants with MBC~rIPT~r marker were detected in single hyphal fragment progenies in thirteen of the seventeen pairings. The percentage of recombinants was about 0.6 - 11.3%. Results showed that vegetative compatibility was prevailing among isolates of M. grisea in Jiangsu Province in vitro. These results also suggested that asexual recombination may be an important mechanism for M. grisea to maintain genetic diversity in nature.