We chose 16 Magnaporthe oryzae isolates with known virulent genes of rice blast to identify the resistance of Hunan 50 rice varieties in vitro. Virulence frequency(FV) of those 16 isolates on rice varieties were analyzed based on resistance phenotype, and resistance gene of rice varieties was presumed according to "gene for gene" theory. The results showed that range of FVon 50 rice varieties was from 31.25% to 93.75%. Among 50 varieties, Jianyou 8 with stronger resistance and broader resistance spectrum was recommended to be planted in Hun...