抗戊唑醇禾谷镰孢菌对渗透压敏感性及电导率变化研究

摘要

The aim of the study is to obtain the resistant isolates of Fusarium graminearum Schw by ultraviolet induction or fungicide-treated myceliums. With the physiology characteristics compared between the sensitive and resistant isolates, we can study on resistance mechanism of Fusarium graminearum to tebuconazole. The resistant I solates were obtained through ultraviolet-induction and tebuconazole-treated myceliums, some isolates could keep stablely resistant level during the period of 17 subcultures. By studying on osmolarity and conductivity, the physiolo gy characteristics of the resistant and sensitive isolates were compared. The results showed that nine resistant mu tants were obtained,the most resistance ratio reached to 180. 06,the lowest resistance ratio showed 34. 26,and five resistant isolates could be keeping high resistance level. In the concentrations of 2. 0% and 4. 0% dextrose,the col ony growth diameter of resistant isolates was bigger than that of their parental isolates. But the colony growth diame ter of resistant isolates and their parental isolates showed no regular in the same concentrations of KC1. In different times,the changes of conductivity to resistant isolates and parental isolates at different concentrations of tebucon azole were obvious,and the changes of conductivity to tebuconazole-treated resistant isolates was bigger than paren tal isolates,and the relative leakage of resistant isolates which were obtained by tebuconazole-treated was common higher than that of resistant isolates by ultraviolet-induction after 200 min. Resistance mechanism of F. Graminearum to tebuconazole might be concern with the change of cell membrane permeability and excrete quickly fungicide in short time.%通过紫外诱导和药剂驯化获取禾谷镰孢菌的抗戊唑醇菌株,探索了抗戊唑醇禾谷镰孢菌的抗药性机制.抗药菌株经转接培养17代后筛选遗传稳定性抗性菌株,利用渗透压法和电导率法测定抗药菌株与亲本菌株之间的生理性差异.所获得的9个抗性菌株,抗性水平最大值为186.03,最小值为34.26.其中,有5个抗性菌株能保持较高的抗性水平.在含2.0％和4.0％的浓度葡萄糖培养基下,抗性菌株的菌落生长直径要比亲本菌株大,而含相同浓度的KC1培养基中,抗性菌株与敏感菌株的菌落生长变化无规律.在不同时间下,抗性菌株和亲本菌株的电导率变化明显,药剂驯化抗性菌株电导率变化比敏感菌株大,经200 min后药剂驯化的抗性菌株比紫外诱导的抗性菌株电导率普遍高.禾谷镰孢菌抗戊唑醇的机制可能与细胞膜通透性的改变和短时间内快速排泄杀菌剂有关.