烟草黑胫病菌对甲霜灵的抗性测定

为合理防治烟草黑胫病，减少抗药性产生，从云南省6个地州分离烟草黑胫病菌菌株34个，就分离菌株对甲霜灵的抗药性进行了测定，结果表明，供试34个菌株中中高抗菌株12个，中抗菌株比例较高5个，低抗菌株17个。不同来源的烟草黑胫病原菌株的抗药性存在差异，以文山、玉溪的菌株抗药性最高，昭通、曲靖菌株抗药性最低，抗性倍数最高达16倍，其余地州抗药性居中。不同地州分离菌株高、中、低抗菌株的比例存在明显差别。分离自楚雄双柏县雨龙乡的113#菌株抗药性最强，来自大理巍山县大仓镇的218#菌株抗药性最低。34株烟草黑胫病菌菌株对甲霜灵的EC50值平均为0.0148μg/ml，范围在0~0.053μg/ml。

Determination of Phytophthora parasitica var. nicotianae Resistance to Metalaxyl

To control tobacco black shank disease rationally, reduce resistance, 34 strains of Phytophthora parasitica var. nicotianae were isolated from 6 region of Yunnan province and all isolates were determined their resistance to metalaxyl. The results indicated that of all tested isolates, there were 12 high resistance, 5 middle resistance and 17 low resistance isolates respectively. The islates fungicide resistance from different region was different obviously, the highest resistant isolate come from Wenshan and Yuxi region, Zhaotong and Qujing isolates had the lowest resistance among all tested isolates. The evident disparity of high-resistance, mid-resistance and low-resistance isolates ratio was exist at different region. 113# from Chuxiong Shuangbai was the highest metalaxyl resistant isolate,and the lowest resistance isolate 218# come from Weishanof Dali. The EC50 of 34 Phytophthora parasitica var. nicotianae isolates against metalaxyl was 0.0148μg/ml in average, was in the range of 0~0.053μg/ml.