水稻纹枯病菌抗井冈霉素突变体的生物学特性

Biological characters of the resistant mutant of Rhizoctonia solani to Jinggangmycin

水稻纹枯病菌野生菌株(Jgms)在含井冈霉素的PSA培养基上连续驯化24代,获得一株抗井冈霉素的突变菌株(Jgmr).毒力测定结果,井冈霉素对Jgmr的EC50为11.6766μg.mL-1,是出发菌株EC50(0.3236μg.mL-1)的36.77倍.Jgmr在不含井冈霉素的PSA培养基上连续培养1-10代后,各代在含10.0μg.mL-1井冈霉素的PSA培养基中的生长速度无显著差异,表明Jgmr具有一定的稳定性.Jgmr与Jgms的培养性状、形态特征与致病力的比较结果表明,Jgmr在PSA培养基中的生长速度、菌核形成量均比Jgms差,两者的菌落和菌丝体形态、菌核色泽与形状明显不同,Jgmr对水稻离体叶片的致病力明显比Jgms弱.

A resistant mutant of Rhizoctonia solani to Jinggangmycin was obtained by being treated with Jinggangmycin taming for 24 generations. The results of bioassay indicated that the ECso of Jinggangmycin on the mutant （Jgm^t） was 11.6766 μg· mL^-1, which was 36.77 times higher than that on the original isolate （Jgm^＊）. When the Jgm＇ was cultivated on PSA medium without the fungicide for 10 generations, there were no significant differences in the sensitivity to Jinggangmycin among the Jgm^r F10 to Jgm^r F0. Some biological characters such as culture, morphology and pathogenicity of Jgm^r were compared with Jgm^r. The results showed that the mycelium growth rate and sclerotia production on PAS plate, as well as pathogenicity in vitro test of Jgm^r were remarkably lower than those of Jgm^r. The distinguished differences in the colony pattern, mycelium morphology, sclerotia shape and colour between Jgm＇ and Jgm were observed.