对多菌灵具有抗性的草莓灰霉病菌菌株形成与分布研究

1987、1989年在江苏的8个县、市和上海市郊采集的草莓上,分别测试了410个和299个灰葡萄孢霉(Botrytis cinerea)菌株对多菌灵的敏感度。发现除少数当年零星种植、未用药防治的田块以外,大多数田块的草莓上都产生了对多菌灵具有高度抗性水平的 B.cinerea 菌株,并对甲基托布津具有交互抗药性。田间的抗药菌株比例与用药水平、草莓种植年限及栽培方式有关。在种植草莓5年以上的塑料大棚内,抗药菌株平均占病原群体的37.69%,已形成抗药性病原亚群体,使多菌灵、甲基托布津的防治效果大为降低。

RESEARCH ON FORMATION AND DISTRIBUTION OF RESISTANT STRAINS TO CARBENDAZIM IN BOTRYTIS CINEREA ON STRAWBERRY

The sensitivity to carbendazim(MBC)was tested in 709 strains of Botrytis cinerea onthe strawberry that were respectively isolated from the areas of Jiangsu and Shanghai in 1987and 1989.The results showed that the strains of B.cinerea with high degree of resistance toMBC have developed in the majority of the strawberry fields except in the scattered anduntreated fields where strawberry was planted for only one year.Cross-resistance exists be-tween MBC and thiophanate methyl.The proportion of the population that exhibits a de-crease from the normal sensitivity of the pathogen relates to the level of using MBC orthiophanate M,and to the number of years and the ways of cultivating strawberry.The highfrequency(average 37.69%)of resistant strains was found in the plastic sheds in whichstrawberry was planted for over five years.MBC and thiophanate M have failed in thesesheds.