【摘要】 采集、分离获得江苏省通州市4乡镇油菜菌核病菌(Sclerotiniasclerotiorum)的223个菌株,对多菌灵(MBC)和乙霉威(NPC)的敏感性测定得到2种表型,其中143个菌株为MBCSNPCHR,其余80个菌株为MBCHRNPCS,后者对温度7～28℃不敏感。苯并咪唑类杀菌剂通过与抗药性相关的β-微管蛋白结合,抑制细胞的有丝分裂。克隆S.sclerotiorum6个菌株的β-微管蛋白基因,获得大小为874个碱基、编码273个氨基酸的基因片段,与典型模式菌粗糙脉孢霉(Neurosporacrassa)进行序列比较发现具高度同源性。研究证明S.sclerotiorum的β-微管蛋白198位氨基酸由谷氨酸(Glu)突变为丙氨酸(Ala),是导致油菜菌核病病原菌产生对多菌灵抗药性的主要原因;突变位点和突变类型与其他抗多菌灵真菌一致,与乙霉威之间存在明显负交互抗性。更多还原

【Abstract】 223 Scletotinia sclerotiorum strains were isolated from Tongzhou of Jiangsu Province. Two phenotypes were identified when tested for sensitivity to carbendazim (MBC) and diethofencarb (NPC). 143 isolates showed phenotype of carbendazin-sensitivity and diethofencarb-highly-resistance (MBCSNPCHR) and other 80 isolates showed carbendazim-highly-resistance and diethofencarb-sensitivity (MBCHRHPCS). The latter was not sensitive to temperature variation between 7～28℃. β-tubulin genes from 6 strains of carbenzim-resistant S.sclerotiorum were cloned and compared the gene nucleotide sequences (874bp) and their deduced amino acid sequences (273 amino acid) with those of the genes of typical carbenzim-resistant fungus, Neurospora crassa. The partial nucleotide sequence of β-tubulin and deduced amino acid of S.sclerotiorum were highly homologous to those from N.crassa. Sequence comparison between MBCS and MBCHR isolates of S.sclerotiorum revealed a single point mutation leading to change at amino acid position 198 from glutamic to alanine acid. This mutation was the same as those identified in benomyl-resistant field isolates of other phytopathogenic fungi, and there existed obvious negative cross-resistance between carbenzim and diethofencarb.更多还原