Abstract: Eleven nitrate nonutilizing (nit) mutants were recovered from six isolates of Magnaporthe grisea cultured on MM media amended with 60 g/L potassium chlorate, with a frequency of 1.42 %. Some biological properties, such as growth rate, growth biomass, cultural characters, conidial production, sexual reproduction ability, and pathogenicity were compared between nit mutants and their parental isolates. Results showed that all the nit mutants were resistant to chlorate. Some important biological properties such as growth rate on YPSA, conidial production ability on TPSA, and pathogenicity, had no significant differences between nit mutants and their parental isolates. Mating type of the mutants hadn’t changed, but perithecia production ability of fertile isolates changed significantly as compared with that of their parental isolates. Therefore, the nit can be used as a genetic marker for study the genetics such as pathogenicity, fungicide resistance in Magnaporthe grisea.

Key words: Magnaporthe grisea, nitrate nonutilizing mutant, biological property, genetic marker

摘要： 将6个稻瘟病菌（Magnaporthe grisea）菌株分别在含60 g/L氯酸钾的MM培养基上培养40 d后，共得到11个硝酸盐利用缺陷突变体（Nitrate nonutilizing mutants，简称nit突变体），频率为1.42 %。比较了各nit突变体与亲本之间在无性和有性阶段的主要生物学性状，结果表明，所有的nit突变体均对氯酸钾产生了抗性。在YPSA平板上的生长速率、在TPSA平板上的产孢量和致病能力等重要的生物学性状都与亲本没有显著差异，交配型没有发生改变，但可交配菌株产子囊壳的能力与亲本有显著差异。因此，可以用nit作为遗传标记研究稻瘟病菌有关性状的遗传学。

关键词: 稻瘟病菌, 硝酸盐利用缺陷突变体, 生物学性状