抗戊唑醇苹果轮纹病菌的紫外诱导及其生物学特性

Ultraviolet induction and characteristics of Botryosphaeria berengriana resistant to tebuconazole

在含戊唑醇的马铃薯葡萄糖琼脂(PDA)培养基上,通过紫外线诱导获得了9株对戊唑醇具有不同抗性水平的苹果轮纹病菌Botryosphaeria berengriana f.sp.piricola抗药性突变体,其抗性指数在11.00～67.88之间。将该抗药性突变体继代培养9代后,大多数突变体的抗性指数逐渐下降,但其中有2株抗药性突变体(UV-TS1-f和UV-TS1-10)仍保持较高的抗性水平;抗药性突变体的致病力与敏感菌株相比未发生明显变化;与敏感菌株一样,抗药性突变体适宜生长的温度也为25～28℃,pH值为7～8;在含不同碳、氮源的培养基中,抗药性突变体的菌丝生长与菌丝干重与敏感菌株相比差异明显。研究表明,苹果轮纹病菌在药剂选择压下易形成抗戊唑醇群体,具有中等或高抗药性风险。

Nine tebuconazole-resistant isolates of Botryosphaeria berengriana f. sp. piricola were obtained by ultraviolet-induction from the media containing tebuconazole. The resistance ratio was from 11.00 to 67. 88. The resistance ratio of most isolates decreased gradually after 9 generations of subcultures in the absence of fungicides ;however isolate UV-TSI-f and UV-TSI-10 still presented high level of resistance after the subcultures. There were no significant difference between resistant and sensitive isolate in pathogenetic ability. The optimal temperature was 25 - 28 ~C, and the optimum pH value was 7 - 8 for both sensitive and resistant isolates. The effects of different carbon and nitrogen sources on the colony growth and mycelial weight were different. The results suggested that resistant isolate of B. berengriana was easily developed under the selection of tebuconazole, and the resistance risk was susceptible to produce resistant moderate or high.