四种土壤处理除草剂对棉花叶片氧化应激防御系统及根系活力的影响

Effects of four kinds of soil- applied herbicides on oxidative stress defense system and root activity of cotton

为了棉田除草剂的科学合理的使用提供科学依据,本研究采用盆栽法对不同浓度乙氧氟草醚、五氟磺草胺、二甲戊灵、仲丁灵对棉苗抗坏血酸含量、抗氧化酶活性、膜脂过氧化、根系活力等生理指标的影响进行了研究。结果显示:施药30 d后,120、180、240 g/hm^2乙氧氟草醚,619、742 g/hm^2二甲戊灵,1008、1152 g/hm^2仲丁灵对棉花幼苗活性氧的积累、细胞膜过氧化、根系活力无显著影响;360 g/hm^2的乙氧氟草醚、1113 g/hm^2的二甲戊灵、1584 g/hm^2的仲丁灵则显著减少活性氧的积累、明显抑制棉花幼苗根系活力和破坏细胞膜完整性;五氟磺草胺各处理均显著影响棉花的氧化应激防御系统,造成活性氧的累积,细胞膜完整性的破坏和根系活力的降低。结论:对棉花较为安全的乙氧氟草醚临界浓度为240 g/hm^2,二甲戊灵临界浓度为742 g/hm^2,仲丁灵临界浓度为1152 g/hm^2,超出临界浓度会不同程度抑制棉花幼苗的生长;五氟磺草胺各处理浓度对棉花生长影响较为严重,棉田杂草防除中不建议使用。

In order to provide scientific basis for the rational use of herbicides in cotton fields, in this study we analyzed the content of ascorbic acid, antioxidant enzyme activity, lipid peroxidation, and root activity of cotton after treated with different concentrations of oxyfluorfen, penoxsulam, pendimethalin, butralin by pot-culture method. The results showed that the accumulation of active oxygen, cell membrane peroxiadation, and root vigor were not significantly affected after application of120, 180 and 240 g/hm^2 oxyfluorfen, 619 and 742 g/hm^2 pendimethalin, 1008 and 1152 g/hm^2 butralin for 30 days. While 360g/hm^2 oxyfluorfen, 1113 g/hm^2 pendimethalin and 1584 g/hm^2 butralin significantly inhibited the root activity, damaged the cell membrane and decreased the accumulation of active oxygen of cotton plants. All treatments of penoxsulam had a significant impact on cotton oxidative stress defense system, which resulted in the accumulation of active oxygen, decrease of root activity and the destruction of cell membrane integrity. It was concluded that 240 g/hm^2 oxyfluorfen, 742 g/hm^2 pendimethalin, 1152g/hm^2 butralin were the critical safe concentrations to cotton, exceedingr the critical concentrations will inhibit the growth of cotton seedling, the different concentrations of penoxsulam on the growth effect of cotton were more serious, and it is not recommended for weed control in cotton field.