烟草灰霉病菌嘧菌酯抗药性突变菌株的诱导及其生物学习性分析

Induction and biological characters of laboratory mutants of Botrytis cinerea resistant to azoxystrobin

【目的】为了解烟草灰霉病菌对嘧菌酯潜在的抗药性风险。【方法】通过紫外诱变诱导烟草灰霉病菌对嘧菌酯的抗药性突变菌株,分析其对嘧菌酯的敏感性和生物学习性。【结果】嘧菌酯对烟草灰霉病菌分生孢子萌发具有较高的抑制作用,其抑制孢子萌发的EC_(50)为2.28 mg/L。紫外诱变获得5株不同抗性水平的嘧菌酯抗药性突变菌株,对嘧菌酯抗性是诱变前菌株的1.69~10.41倍。继代培养11代后,各突变菌株对嘧菌酯的敏感性稳定;突变菌株菌丝生长速度高于或低于初始菌株;所有突变菌株的分生孢子产量和萌发率均低于初始菌株;突变菌株菌核产量同初始菌株一致或有所降低;所有突变菌株具有致病力,部分致病力强于初始菌株。【结论】嘧菌酯对烟草灰霉病菌分生孢子萌发具有较强的抑制作用;若使用嘧菌酯防治烟草灰霉病,存在烟草灰霉病菌对嘧菌酯产生抗药性的风险。

The aim of current study was to investigate possible resistance risk of B. cinerea to azoxystrobin. [Methods] The azoxystrobinresistant isolates were induced by UV mutation. Fungicide sensitivity and biological characters of all isolates were analyzed. Results showed that Azoxystrobin presented high inhibition against conidial germination of B. cinerea, with EC50 value of 2.28 mg/L. Total five resistant isolates at different resistant levels were obtained by the UV mutation, and the range of resistant ratio was from 1.69 to 10.41. Biological character studies showed that all resistant isolates had stable sensitivity to the fungicide azoxystrobin after 11 continuous generations. The mycelial growth ratio of all resistant isolate was higher or lower than that of original isolate of B. cinerea. The conidia production and germination of all resistant isolates was lower than that of original isolate. The sclerotium production of resistant isolates was the same or lower than that of original isolate. All resistant isolates had pathogenicity on tobacco detached leaf, and some showed much stronger pathogenicity. [Conclusion] Azoxystrobin showed high activity against conidial germination of B. cinerea. If tobacco gray mold was controlled with azoxystrobin in the future, B. cinerea from tobacco had the fungicide resistant risk to azoxystrobin.