中国河南省小麦纹枯病菌对咯菌腈的敏感性

为明确河南省小麦纹枯病菌对咯菌腈的敏感性，采用菌丝生长速率法测定了咯菌腈对2013年从河南省15个地市分离的98株病菌的毒力。结果表明:咯菌腈对供试小麦纹枯病菌菌株的EC50值在0.009~0.079 μg/mL之间，平均EC50值为(0.025 ±0.012)μg/mL；98个菌株对咯菌腈的敏感性分布呈连续单峰曲线，未出现敏感性下降的亚群体，可将(0.025 ±0.012)μg/mL作为小麦纹枯病菌对咯菌腈的敏感性基线；方差分析(LSD法)及SPSS聚类结果均显示，同一地市内的菌株对咯菌腈的敏感性差异较大，EC50最大值和最小值之比在1.0~4.1之间，而不同地区菌株间对咯菌腈敏感性差异不明显，咯菌腈EC50平均值变化范围在0.015~0.060 μg/mL之间，后者是前者的4倍；小麦纹枯病菌对咯菌腈的敏感性与其对噻呋酰胺、苯醚甲环唑、井冈霉素、丙环唑及戊唑醇的敏感性之间无明显相关性。本研究结果可为河南省小麦纹枯病防控杀菌剂的合理使用提供理论依据。

Sensitivity of Rhizoctonia cerealis to fludioxonil in Henan Province in China

In order to evaluate the sensitivity of Rhizoctonia cerealis to fludioxonil, 98 isolates were collected and identified from 15 cities in Henan Province in 2013. Their sensitivities to fludioxonil were determined by measuring the mycelial growth on the fungicide-amended media. The results indicated that the EC50 values of all isolates ranged from 0.009 to 0.079 μg/mL and the average EC50 value was (0.025 ±0.012) μg/mL. The sensitive frequency analysis of R. cerealis to fludioxonil distributed as a unimodal curve, which demonstrated that resistant subpopulation didn't exist among these isolates.So the average EC50 value was treated as the sensitive baseline of R. cerealis to fludioxonil. The results of both variance analyses by LSD test and hierarchical cluster analysis by SPSS indicated that the isolates collected from the same region exhibited different sensitivities. The ratio of the maximum and the minimum of EC50 values of isolates from the same region ranged from 1.0 to 4.1. However, there was no significant difference on the sensitivity to fludioxonil among the isolates from most of the regions. From all the regions, the average EC50 value of the isolates ranged from 0.015 to 0.060 μg/mL and the maximum value was 4 times of the minimum. Especially, the correlation efficient existed between the sensitivity to fludioxonil and the sensitivities to thifluzamide, difenoconazole, tebuconazole, propiconazole or jinggangmycin was very low, which implied that there was no sensitivity correlation between fludioxonil and these six fungicides. The results provided a theoretical basis for the rational application of fludioxonil in the control of wheat sharp eyespot in the field of Henan Province.