Abstract: 【Objective】 The objective of this study is to test sporulation abilities and steady, pathogenicity, and relativity between the sporulation and pathogenicity of 150 strains of Ustilaginoidea virens. 【Method】A total of 150 strains of U. virens were collected from 9 provinces of China. Their sporulation abilities and pathogenicity were tested by liquid culture and artificial inoculation.【Result】The conidia-producing standard deviation of 132 strains was smaller than 10.0 in three conidia-producing tests, accounted for 88.0% of all strains. Three rice cultivars were inoculated with 150 strains. In the susceptible rice cultivar, Liangyoupeijiu, the average disease index of rice false smut was 67.7, the disease index of 98 strains were more than 50. In the medium resistance cultivar, Huaidao5, the average disease index was 21.8. In the resistant cultivar, Wuyujing3, the average disease index was 16.1, the disease index of 113 strains were shorter than 25. The results indicated that there was a positive relationship between the sporulation and pathogenicity, their correlation coefficient was on the low side, their correlation coefficient was medium-low. According to the pathogenicity of the 150 strains on three rice cultivars, they were divided into 7 pathogenic types. Pathogenic type III (resistant to Wuyujing 3 and Huaidao5, susceptible to Liangyoupeijiu) had 53 strains of U. virens, accounted for 35.3% of all strains, and it was a superior pathogen type. 【Conclusion】The sporulation of U. virens was steady. There was a positive relationship between the sporulation and pathogenicity. There were two interactions between 150 strains of U. virens and three rice varieties with different resistances, one was weak interaction which great majority strains showed, another was strong interaction which few strains showed.

Key words: Ustilaginoidea virens, sporulation, pathogenicity, pathogenic type