ABSTRACT
Eight isolates of Colletotrichum gloeosporioides isolated from host plants Cunninghamia lanceolata lanceolata and Euonymus japonichum, respectively, were cultured on MMC medium containing KCIO3 to select chlorate-resistant and nitrate non-utilizing mutants (Nit). All the Nit mutants obtained by this way belong to one of 3 kinds of the following phenotypes: the nitrate reductase structural locus (nit1), the nitrate-assimilation pathway-specific regulatory locus(nit3), and the molybdenum-containing cofactor locus(nitM). The higher mutation frequency on MMC amended with increasing concentration of KCIO3 was induced, and various nitrogen sources were able to influence production of the phenotypic classes. Seven of the 8 isolates tested were self-compatibility in which the two mutants with different phenotypes from the same isolate could genetically complement. The two isolates frail C. lanceolata belong to the same vegetative compatibility group (VCG), the other six isolates belong to distinctive VCGs.