禾谷丝核菌对戊唑醇的抗性及抗药性菌系生物学特性

在含戊唑醇PDA平板培养基上，对禾谷丝核菌进行逐代处理，以诱导其抗药性菌系；比较抗性和敏感菌系的生物学特性，测定抗性菌系对其它杀菌剂的交互抗性。结果表明，选育至35代，对戊唑醇抗性达33．4倍。抗戊唑醇菌系与敏感亲本菌系相比，其菌丝生长速率、菌丝干重、菌核产生速率、菌核数及干重均存在差异。抗性菌系较敏感菌系对冬小麦幼苗的致病力减弱，但小麦返青后抗性菌系引起的发病率和严重度均较敏感菌系增强。戊唑醇抗性菌系对三唑酮、丙环唑、井冈霉素、福美双、噁醚唑和咯菌腈6种药剂分别产生了31．2、22．8、16．9、15．8、15．5和1．6倍的交互抗性。

Resistance of Rhizoctonia cerealis to tebuconazole and the biological characters of tebuconazole-resistant strains

The resistant strain of R. cerealis was selected after 35-times cultivation on the media containing tebuconazole, then the biological characters of the resistant and sensitive strains and the cross resistance of the resistant strain to some fungicides were studied. The results showed that after 35-times selection, the resistance of Rhizoctonia cerealis reached 33. 4 fold to that of tebuconazole. Great difference in the rate of mycelial liner growth, dry weight of mycelial, number and dry weight of sclerotium were found between the resistant and sensitive strains. The pathogenicity of the resistant strain was weaker than the sensitive strain in winter wheat, but the incidence and sensitivity of the resistant strain were highter than that of sensitive strain in next spring. The cross resistance of resistant strain of R. cerealis to tridimefon, propi-conazole, validamycin, thiram, difenoconazole and fludioxoni were 31. 2, 22.8, 16.9, 15.8, 15. 5 and 1.6 folds respectively.