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期 刊 ：植物保护学报 2011年

关键词：稻瘟病菌；稻瘟灵；异稻瘟净；三环唑；抗药性；

Keywords:Magnaporthe grisea, isoprothiolane, iprobenfos, tricyclazole, fungicide resistance,

摘 要 ：采用菌丝生长速率法分别测定了57株稻瘟病菌对稻瘟灵和79株稻瘟病菌对异稻瘟净的敏感性,分别建立了敏感基线,并检测了141株大田稻瘟病菌对稻瘟灵和异稻瘟净的抗药性水平;采用活体植株法测定了223株稻瘟病菌对三环唑的敏感性。57株稻瘟病菌对稻瘟灵的平均EC₅₀值为1.4312±0.0867 μg/mL,其敏感性频率分布呈连续性单峰曲线,1.4312 μg/mL可作为稻瘟病菌对稻瘟灵的敏感基线,在141株大田稻瘟病菌中敏感、低抗和中抗菌株出现的频率分别为21.99%、73.76%和4.26%;79株稻瘟病菌对异稻瘟净的平均EC₅₀值为6.6393±0.2662 μg/mL,其敏感性频率分布也呈连续性单峰曲线,6.6393 μg/mL可作为稻瘟病菌对异稻瘟净的敏感基线,141株大田稻瘟病菌中敏感、低抗和中抗菌株出现的频率分别为90.07%、7.80%和2.13%。稻瘟病菌对三环唑的EC₅₀值最大为47.6144 μg/mL,最小为1.0850 μg/mL,供试菌株的EC₅₀值呈近似正态分布,未出现敏感性下降的抗药性亚群体。

Abstract:The sensitivity of the 57 Magnaporthe grisea strains to isoprothiolane and the sensitivity of the 79 M.grisea strains to iprobenfos were established with mycelium growth rate method, and the sensitivities of 141 isolates from fields were determined to monitor the resistance to isoprothiolane and iprobenfos. The sensitivity of the 223 M.grisea strains to tricyclazole was detected in vivo. The results showed that the EC₅₀ of isoprothiolane and iprobenfos to M.grisea were 1.4312±0.0867μg/mL and 6.6393±0.2662μg/mL, which showed a unimodal distribution. Thus, 1.4312μg/mL and 6.6393μg/mL could be used as baseline-sensitivity of M.grisea to isoprothiolane and iprobenfos for field resistance monitoring, respectively. And the frequencies of sensitive, low-resistant and intermediate-resistant isolates from fields to isoprothiolane were 21.99%, 73.76% and 4.26%, to iprobenfos were 90.07%, 7.80% and 2.13%, respectively. All the 223 isolates were sensitive to tricyclazole with EC₅₀ ranging from 1.0850 to 47.6144μg/mL, which showed a skewed unimodal distribution, and no resistant subpopulation was detected among these strains.

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