氯苯醚酰胺(Y13149)生物活性初步研究及水稻纹枯病菌对其敏感性基线的建立

Bioactivity of Y13149 and its sensitivity baseline of Rhizoctonia solani

氯苯醚酰胺[N-(2-(2,4-二氯苯氧基)苯基)-3-(二氟甲基)-1-甲基-1H-吡唑-4-酰胺,Y13149]是由华中师范大学基于药效团连接碎片虚拟筛选策略(PFVS)快速发现的新型琥珀酸脱氢酶抑制剂类(SDHIs)化合物。采用菌丝生长速率法,测定了该创制化合物的农药生物活性。结果表明:氯苯醚酰胺对真菌具有较广的抗菌谱,对供试10种植物病原真菌均具有较好的抑制活性,EC50值在0.008~15.25 mg/L之间,其对立枯丝核菌的抑制活性最强,但对辣椒疫霉和链状腐霉活性较弱。田间试验表明,氯苯醚酰胺对水稻纹枯病具有较好的防治效果,有效剂量75 g/hm2时的平均防效为79.6%,其防效总体略好于噻呋酰胺(75 g/hm2的平均防效为77.3%)。此外,氯苯醚酰胺对采自浙江和江苏两省的125株水稻纹枯病菌的EC50值分布在0.002~0.259 mg/L之间,且呈近似正态单峰曲线,平均EC50值为(0.021±0.008)mg/L,因此可将其作为水稻纹枯病菌对氯苯醚酰胺的敏感性基线,用于田间抗药性监测。

The bioactivity of Y 13149, N-（2-（2,4-dichlorophenoxy） phenyl）-3-（difluoromethyl）＂ 1 - methyl-lH-pyrazole-4-carboxamide, a novel succinate dehydrogenase inhibitor discovered through pharmacophore-linked fragment virtual screening by Huazhong Normal University, was evaluated by the method of mycelial growth rate. Results indicated that it exhibited good inhibitory activities against 10 tested plant-pathogenic fungi with the EC50 of 0.008-15.25 mg/L and the highest inhibition rate was observed in the case of Rhizoctonia solani. However, Y13149 had lower activities against Phytophthora capsici and Pythium catenulatum. In field experiments, the control efficacy of Y 13149 for the rice sheath blight disease is, on average, 79.6% at the dose of 75 g/hm2, which is comparable with that of trifuzamide （77.3% at the dose of 75 g/hm2）. Further study suggested that the ECs0 for the tested population （n = 125） of R. solani collected from Zhejiang and Jiangsu Province fitted unimodal distribution and varied from 0.002 to 0.259 mg/L with the mean of （0.021 ± 0.008） mg/L, which could be adopted as the baseline sensitivity ofR. solani to Y13149 to monitor the sensitivity shift.