水稻白叶枯菌对叶枯宁的抗药性活体产生规律初探

在网室稻株上试验表明,水稻白叶枯菌对叶枯宁和敌枯双都易产生抗药性。250ppm施一次后,病叶中遗留(?)的抗药性都上升了,病菌抗性上升到5倍以上的病叶占3/10;施二次药后,病斑中的遗留菌基本上都是抗性菌,与原始敏感菌相比,其EC_(50)至少上升了11倍,能抗16000ppm的叶枯宁,叶枯宁用于保护时产生抗性的机率要比治疗时少。这种抗性现象可解释叶枯宁使用时间及次数的药效差异现象,也可为正确使用叶枯宁提供理论依据。

A Research on the Chemical Resistance of Rice Leaf Blight Bacteria to YEKUNING in vivo.

The experiments in vivo in net house showed that the chemical resistance of Rice Leaf Blight Bacteria developed rapidly on YEKUNING and DIKUSHUANG After 250 ppm YEKUNING was sprayed once the resistance of the bacteria in all sprayed leaves increased. The resistance of the bacteria in three of ten those leaves was more than 5 times that of sensitive ones. After 250 ppm YEKUNING was sprayed twice the bacteria in all sprayed leaves were chemical resistant ones. Their EC50 increased at least 11 times that of sensitive ones and they could overcome 16000ppm YEKUNING. When YEKUNING was used as a preventive agent, the rate of resistance appearance was lower than as a curative agent. This chemical resistance of the bacteria could explain the differences in the effects of using stage and times of YEKUN-ING and could provide us with the theoretical basis of correct use of YEKUNING.