咯菌腈和戊唑醇复配对假禾谷镰孢菌丝生长及所致病害的影响

Effects of fludioxonil and tebuconazole mixtures on mycelial growth and disease of Fusarium crown rot

为筛选对小麦茎基腐病安全且有效的药剂组合,本研究采用菌丝生长速率法检测不同作用机制的杀菌剂咯菌腈与戊唑醇复配对病原菌假禾谷镰孢的毒力,筛选出最佳增效组合,进而利用温室苗期生物测定明确复配药剂的安全性及防治效果,最后利用qPCR检测复配药剂对小麦根际土壤及茎秆中病原菌的影响。结果表明:咯菌腈与戊唑醇质量比为1∶7的复配药剂对假禾谷镰孢菌丝生长毒力最强,平均增效系数为7.22;该组合复配种衣剂在3个不同抗性小麦品种上温室苗期防治效果分别为73.35%、62.59%和82.07%,显著高于同剂量的两个单剂,且兼有促生作用;对小麦根长、鲜质量分别提高了2.81%~12.33%和18.87%~49.21%。通过qPCR检测发现,使用该复配药剂与空白对照相比假禾谷镰孢含量在小麦根际土壤中降低76.95%~90.37%,在小麦茎秆组织中降低92.00%~96.70%。验证了咯菌腈与戊唑醇质量比为1∶7的复配剂可通过降低土壤和小麦茎秆组织中病原菌的含量从而达到防治效果。本研究为小麦茎基腐病的化学防治提供新的参考依据。

In order to screen the safe and effective mixtures of fungicides for Fusarium cown rot,the toxicity of the mixtures of fungicides with different modes of action fludioxonil and tebuconazole against Fusarium pseudograminearum was detected by mycelial growth rate method,and the optimum synergistic mixture was selected.The safety and control effect of the fungicide mixture were determined by seedling bioassay in greenhouse.Finally,qPCR was used to detect the effects of the fungicide mixture on the pathogens in wheat rhizosphere soil and stem.The results showed that the toxicity of the mixture to hyphal growth of F.pseudograminearum was highest when the ratio of fludioxonil and tebuconazole was 1∶7 with the synergistic ratio of 7.22.The control effects of the seed coating agent for the mixture were 73.35%,62.59%and 82.07%on three different disease resistant wheat varieties,respectively,which was significantly higher than the two single fungicides used at the same dose.It also had the growth promoting effect,and increased the root length and fresh weight of wheat by 2.81%-12.33%and 18.87%-49.21%respectively.Compared with the control,the contents of F.pseudograminearum in wheat rhizosphere soil and wheat stem treated with the mixture were decreased by 76.95%-90.37%and 92.00%-96.70%,reapectively.It was verified that the ratio of the mixture of fludioxonil and tebuconazole at 1∶7 could achieve the control effect by reducing the content of the pathogen in soil and wheat straw.This study provides a new reference for the chemical control of Fusarium cown rot.