应用溴甲酚紫指示剂检测贵州省稻瘟病菌对稻瘟灵的敏感性

The sensitivity test of Magnapothe griseato isoprothiolane by bromocresol purple approach in Guizhou Province

采用加溴甲酚紫生长速率抑制法测定采自于贵州省的63个稻瘟病菌株对稻瘟灵的敏感性.结果表明：稻瘟灵作用一定时间后,在含有指示剂和稻瘟灵的培养基中稻瘟病菌饼周围呈现的颜色跟稻瘟灵的浓度有一定的关系,在4μg·mL^-1以下呈现出紫色且颜色的深浅随着稻瘟灵浓度的增加而逐渐变淡,4μg·mL^-1处呈现橙红色,此浓度下稻瘟灵对稻瘟病菌的抑制率可达到80%左右.贵州省三地稻瘟病菌对稻瘟灵的EC50值为1.41-6.26μg·mL^-1,稻瘟病菌对稻瘟灵的敏感基线定为3.283 33μg·mL^-1,大部分稻区的稻瘟病菌株均表现为敏感或低抗水平,同时三地稻瘟病菌对稻瘟灵的抗性水平存在一定程度上的时空差异。

The Magnapothe grisea＇s sensitivity was tested on isoprothiolane by bromocresol purple approach from Guizhou.After a period of time,the researchers found that the Magnapothegrisea disk＇s color will change with the isoprothiolane＇s concentration in medium which contained indicator and isoprothiolane.When the concentration is lower than4μg· mL^-1,it is purple and the color depth is decreased with the isoprothiolane concentration increased.The concentration of 4 μg· mL^-1 presents orange red and the inhabitation ratio reached 80 percent.The results showed that the EC50 of the strains to isoprothiolane ranged from 1.41-6.26μg·mL^-1,the sensitive base-line of Magnapothe grisea＇s isolates to isoprothiolane was 3.283 33μg·mL^-1in Guizhou,most of isolates were low resistant to isoprothiolane.The sensitivity of strains belonging to different Magnapothe grisea＇s to isoprothiolane had time and space differences.