| Ten strains of Ustilaginoidea virens collected from 5 provinces of China were cultured in solid and liquid media, and their culture characteristics, sporulation abilities and pathogenicity were tested by artificial inoculation in green house. The pathogenicity was evaluated by inoculating 3 strains of the pathogen on 12 rice varieties. The results showed that there was significant difference of pathogenicity among different strains of U. virens, as well as the response of different rice varieties. The strains cultured on solid medium could be divided into 7 types. The pathogenicity of U. virens was correlated with the sporulation and growth pattern on solid media, but was not correlated with the mycelia production and pigment in liquid media. We verified the protocols for single spore isolation as of flame -burning surface tissue separation, conidia crossed dilution techniques, and injecting inoculation technique using mycelia-spores mixed inoculums in booting stage under temperature and humidity controlled conditions in green house. By using this method, high success rate of pathogen isolation and inoculation could reach up to 100%. So the method is useful for screening rice false smut resistance and related research. |
