稻恶苗病菌抗感多菌灵菌株的nit突变株形成

从江苏、河北、上海等地采集的水稻恶苗病株上分离到抗、感多菌灵的稻恶苗病菌菌株中，选用７个抗性菌株和６个敏感菌均获得氯酸盐的硝酸盐利用缺陷突变体。

FORMATION OF NIT MUTANTS FROM MBC RESISTANT AND SENSITIVE ISOLATES OF FUSARIUM MONILIFORME

Seven carbendazim (MBC) resistant and six MBC sensitive isolates of Fusarium moniliforme were isolated from bakanae diseased rice plants collected in Jiangsu, Shanghai and Hebei. All of the 13 isolates produced chlorate resistant sectors on MM media amended with 1.5% KClO 3 and nitrate nonutilizing mutants(nit mutant), which were recovered by transfering the chlorate resistant sectors to the media containing nitrate as the nitrogen source. All nit mutants were as sensitive to MBC as the parent isolates of wild type. When the nit mutants were paired, the MBC resistant isolates obtained from different area were complementary, the MBC sensitive isolates were frequently complementary even between the isolates obtained from different area. but the MBC resistant isolates showed in no case the complementary reaction with the MBC sensitive isolates regardless their geographical origin.The stability of nit mutants was demonstrated by culturing them for different periods with various condition. The spore density and pathogenicity to rice (cv. Wuyugen No. 3) were significantly lower in the nit mutants than that in the parent isolates.