烟草赤星病菌对菌核净的抗药性测定

为合理防治烟草赤星病,减少抗药性产生和农药残留,从云南省11个地州分离烟草赤星病菌菌株96株,就分离菌株对菌核净的抗药性进行了测定,结果表明,供试菌株中高抗菌株28个,中抗菌株39个,低抗菌株29个。不同来源的烟草赤星病原菌株的抗药性存在差异,以思茅、大理的菌株抗药性最高,昆明、红河、临沧抗药性最低。不同地州分离菌株高、中、低抗菌株的比例存在明显差别。大理永平昌街七昌村分离菌株AL208#抗药性最强,抗性倍数达20.30,玉溪市红塔区的菌株AL171#抗药性最低。96株烟草赤星病菌菌株对菌核净的EC50值平均为81.34 mg/L,范围在13.28~269.58 g/L。

Determination of dimethachlon resistance in Alternaria alternata

To control tobacco brown spot disease rationally,reduce resistance to fungicide and reduce pesticide pollution,96 strains of Alternaria alternata were isolated from 11 region of Yunnan province and all isolates were determined their resistance to dimethachlon.The results indicated that of all tested isolates,there were 28 high resistance,29 middle resistance and 29 low resistance isolates respectively.The islates fungicide resistance from different region was different obviously,the highest resistant isolate come from Dali and Simao region and the Kunming,Honghe,Lincang isolates had lowest resistance among all tested isolates.The evident disparity of high-resistance,mid-resistance and low-resistance isolates ratio was exist at different region.AL208# from Dali Yongping was the highest dimethachlon resistant isolate,its resistance multiple arrived to 20 compared to the lowest resistance isolate AL171#,which from Hongta District of Yuxi City.The EC50 of 96 Alternaria alternata isolates was 81.34 mg/L in average,was in the range of 13.28-269.58 mg/L.