醚菌酯对假禾谷镰孢的抑制作用及对小麦茎基腐病的防效研究

 为了明确醚菌酯对假禾谷镰孢的抑制作用,本研究采用菌丝生长速率法和孢子萌发抑制法分别测定了醚菌酯对2019年从河南省13个地市分离的50株假禾谷镰孢的毒力。两种方法结果表明,醚菌酯对供试50株菌株的EC₅₀值范围分别在0.127 3~3.070 9 μg·mL^-1和0.001 3~0.070 9 μg·mL^-1,平均EC₅₀值为(1.304 1±0.804 2)μg·mL^-1和(0.017 4±0.017 0)μg·mL^-1。敏感性频率分布图显示,两种方法分别有80％(40株)和70％(35株)的菌株敏感性频率呈正态分布,其平均EC₅₀值分别为(1.135 2±0.531 2)μg·mL^-1和(0.011 4±0.006 3)μg·mL^-1,可作为假禾谷镰孢对醚菌酯的敏感性基线。方差分析结果表明,同一县市的假禾谷镰孢对醚菌酯的敏感性差异较大,EC₅₀值变化范围为0.545 2~2.156 4 μg·mL^-1和0.001 9~0.036 7 μg·mL^-1。聚类分析结果显示,河南省假禾谷镰孢对醚菌酯敏感性差异与菌株的地理来源无明显关联性。温室防效结果显示,小麦种子与醚菌酯悬浮种衣剂进行拌种处理可以起到一定防治效果,0.42 μL AI/2g处理防效最高,防治效果可达50.33％。本研究结果可为河南省假禾谷镰孢对醚菌酯的敏感性监测提供信息,同时为醚菌酯对小麦茎基腐病的防治提供理论依据。

Inhibitory effect of kresoxim-methyl on Fusarium pseudograminearum and control effect on crown rot of wheat

In this study, the inhibitory effect of kresoxim-methyl to 50 Fusarium pseudograminearum strains isolated from 13 cities in Henan Province in 2019 based on the mycelial growth and spore germination methods, respectively. The results showed that the EC₅₀ values of kresoxim-methyl to the 50 tested strains were in the range of 0.127 3-3.070 9 μg·mL^-1 and 0.001 3-0.070 9 μg·mL^-1 for the two methods, respectively. And the average EC₅₀ values were (1.304 1±0.804 2) μg·mL^-1 and (0.017 4±0.017 0) μg·mL^-1, respectively. 80% and 70% of the tested strains were with continuous single peak frequency distribution and their average EC₅₀ values at (1.135 2±0.531 2) μg·mL^-1 and (0.011 4±0.006 3) μg·mL^-1, respectively, which could be used as the baseline sensitivity of F. pseudograminearum to kresoxim-methyl for the two methods. The sensitivity to kresoxim-methyl was varied for the strains from the same city with the EC₅₀ values in the range of 0.545 2-2.156 4 μg·mL^-1 and 0.001 9-0.036 7 μg·mL^-1 for the two methods, respectively. The results of cluster analysis showed that there was no significant correlation between the sensitivity of F. pseudograminearum strains to kresoxim-methyl and their geographical origin. The wheat seeds mixed with kresoxim-methyl suspension had a certain control effect in a greenhouse test where 0.42 μL AI/2g treatment had the highest control effect at 50.33％. The results of this study could provide a theoretical basis for the using of kresoxim-methyl in the control of wheat crown rot caused by F. pseudograminearum.