Abstract:To study the pathotypes of Magnaporthe oryzae in southwestern Hubei Province,seven Chinese identification rice cultivars and 15 nearisogenic lines of rice with single blast resistant gene were inoculated with 136 strains isolated from rice infected during 2012 to 2014,using Lijiangxintuanheigu(LTH) as susceptible control.The results showed that 121 strains with pathogenicity to LTH were belonged to 13 physiological races in 6 groups including ZA,ZB,ZC,ZE,ZF,and ZG based on the pathogenicity to the seven Chinese identification rice cultivars.Among these groups,ZB was the dominant population,while ZC increased significantly over the years,reaching about the same frequency as ZB in 2014.ZB13 was the first dominant physiological races,while ZC15 and ZB15 increased significantly over the years.According to the phenotypes of the 15 nearisogenic lines after inoculation,the 121 strains were divided into 77 pathogenic types,among which strains isolated from different years exhibited large difference in virulence.Over 90% of the strains tested were virulence tomonogenic rice lines with Pib,Pit,and Pi11,while less than 10% were virulence tomonogenic rice lines with Pi9 and Pikh.It will provide guidelines for local farmers,breeders,and agricultural sectors in choosing and developing rice varieties in this region.