Objective   Physiological races of Magnaporthe grisea, the major pathogen of rice blast disease in Fujian in recent years, and the rice varieties resistant to the infection were studied to understand the fungal distribution and provide a clue for breeding to prevent the disease.

  Method   Microbial samples from the diseased rice in 17 localities in the province were collected from 2017 to 2019. Monospores were isolated and classified by comparing with 7 species with known identifications. From them, 60 distinctive strains were sprayed indoor on 32 local rice varieties to detect the presence of 9 molecular markers of rice blast resistance genes on the inoculated rice plants.

  Result   Using the 7 specimens with known identification and classification for comparison, the ZA group with an occurrence frequency at 39.48% was found to be the dominant physiological race of rice blast. Inoculation of the 60 physiological races on the 32 rice varieties showed an average pathogenicity rate of 23.28%. The relatively low infection rate suggested that most of the local rice were blast resistant to varying degrees. Subsequently, 15 of the rice varieties with broad resistance spectra were identified. Of which, Longliangyouhuazhan and Liangyou 332 exhibited the broadest spectra and were considered suitable for further applications.

  Conclusion   The dominant physiological race of M. grisea appeared to have gradually changed over recent years from ZB and ZC to ZA group in Fujian. The transformation might relate to the large-scale promotion of the Yongyou rice series during the time. Consequently, it would be prudent in selecting rice varieties with a broad-spectrum on blast resistance for promotion. And, prior to introducing a new variety, an understanding of the origin of pathogenic physiological races would be necessary to preclude areas that are susceptible to the spread of the disease for the cultivation.