Pathotype Structure of Magnaporthe grisea in the Fields of Chongyang and Yuan’an in Hubei Province,China

Objective] This study aimed to explore the pathotype structure of Magnaporthe grisea in Chongyang and Yuan’an in Hubei Province,China.Method] From the rice-growing fields of Chongyang and Yuan’an in Hubei Province where rice blast occurs frequently,60 isolates which were pathotyped against two sets of host differentials:Chinese host differentials and CO39 NILs,were obtained.Then,20 pathotypes with the six indica host differentials(CO39 NILs) were observed,while 13 pathotypes in four race groups were observed out of the same single spore isolates with Chinese host differentials which consists of three indica cultivars and four japonica cultivars.The diversity of the pathotypes of M.grisea populations tested by CO39 NILs was 2.54 and the pathotype 137.1 occurred at predominantly high frequency(21.67%).The diversity of physiological races of M.grisea populations tested by Chinese host differentials was 1.22 and the race group ZA occurred at predominantly high frequency(73.33%).The diversity of physiological races of M.grisea in Chongyang and Yuan’an were also calculated.Overall,the diversity of pathotypes of M.grisea in Yuan’an was higher than that in Chongyang with the two sets of the host differentials.Conclusion] This study provided current information on the pathotype spectrum of M.grisea populations in the rice fields of Hubei Province to allow the formulation of viable strategies for blast resistance breeding programs in Hubei Province.