Abstract：The rice blast fungus Magnaporthe grisea causes one of the most destructive diseases of rice around the world. Mutant generation is the basic work to study mutation mechanism of Magnaporthe grisea. Based on the transformation system established by our laboratory, A large scale of mutants were generated through T-DNA insertion Agrobacterium tumifaciens-mediated transformation(ATMT), in which some morphology and pathogenicity mutants were obtained. In the paper, we selected 28 mutants from among those mutants for further research, including morphology and development observation. Within 28 selected mutants, it was found that there were 15 color abnormal in colony mutants, 8 decreased growth rate mutants, 2 abnormal in conidium morphology and sporulation mutants, 2 abnormal appressorium mutants and 3 appressorium defective mutants. By inoculation the conidia of the mutants on the susceptible rice variety Nipponbare and resistant variety C101(as control). Of the 28 mutants tested, 9 showed completely pathogenicity lost and disease grade 0. By cross cultivation of the mutants with the mating type testers (P131 and 1528), we found 3 mutants(Y34-0211,Y34-1469 and Y34-0635) completely lost the ability to turn their anamorph into teleomorph phase, while this ability of other mutants tested remained the same as the wild type.
