辽宁省稻瘟病菌对烯肟菌酯敏感基线及抗药性风险研究

从辽宁省8个地区从未使用过烯肟菌酯的水稻田中共采集分离了122株稻瘟病菌菌株。采用菌丝生长速率法测定其对烯肟菌酯的敏感性,结果表明,不同地区的菌株敏感性存在一定的差别,最敏感的是抚顺菌株,其EC50平均值为1.2678μg·mL-1;最不敏感的是营口菌株,其EC50平均值为1.5576μg·mL-1。所有菌株的EC50平均值1.4176μg·mL-1,可作为稻瘟病菌对烯肟菌酯的敏感基线。经紫外线照射,获得了两个抗药性突变菌株,其抗药性倍数分别为5.29和8.46。抗药性突变菌株的菌丝生长速率及产孢能力均低于野生菌株。由此可见,稻瘟病菌对烯肟菌酯产生抗药性的风险较低。

Baseline Sensitivity and Resistance Risk of Magnaporthe grisea to Enestroburin in Liaoning Province

In 2005-2006,122 Magnaporthe grisea isolates were obtaind from paddy fields from 8 cities of Liaoning Province without using enestroburin fungicide.Baseline sensitivity was determined by the method of mycelial growth inhibition.The most sensitive isolates were from Fushun,its EC50 was 1.267 8 μg·mL-1;the least sensitive one was from Yingkou,its EC50 was 1.557 6 μg·mL-1.The average EC50 1.417 6 μg·mL-1 is the baseline-sensitivity of Magnaporthe grisea to enestroburin.Two UV mutants with 5.29 and 8.46 resistance times to enestroburin were obtained from wild-type isolates.The mutants showed reduced growth and sporulation.The results suggest a low resistance risk for Magnaporthe grisea to enestroburin.