赤霉素缓解Mn~(2+)对草甘膦拮抗效应的研究

为探索能够减轻或消除Mn2+对草甘膦拮抗效应的方法,以高羊茅为试材,将赤霉素(GA3)与草甘膦和硫酸锰(Mn2+质量分数为0.1%)混用,研究了赤霉素对Mn2+降低草甘膦药效的缓解作用。结果表明:赤霉素+草甘膦+硫酸锰处理组高羊茅比同剂量草甘膦+硫酸锰处理组叶色更黄,萎蔫更严重,与同剂量草甘膦单剂处理组比较接近,其中加入50 mg/L赤霉素处理组缓解草甘膦拮抗效应的效果最好。赤霉素+草甘膦+硫酸锰处理组高羊茅的干、鲜重及叶绿素含量均低于草甘膦+硫酸锰处理组,而丙二醛和莽草酸含量均明显高于草甘膦+硫酸锰处理组。处理后第6天,赤霉素+草甘膦+硫酸锰组莽草酸含量分别比草甘膦+硫酸锰组增加了49.8%(加入50 mg/L赤霉素)和28.8%(加入30 mg/L赤霉素),差异显著;处理后第2天,赤霉素+草甘膦+硫酸锰组丙二醛含量分别比草甘膦+硫酸锰组增加了54.1%(加入50 mg/L赤霉素)和52.9%(加入30 mg/L赤霉素),差异显著。研究表明,将赤霉素与锰肥和草甘膦混合喷施,将有可能在一定程度上缓解Mn2+对草甘膦的拮抗效应,保证草甘膦的除草效果。

Alleviation effect of gibberellin A3 on antagonism of manganese to glyphosate

MnSO₄, applied as a foliar fertilizer in tank mixtures with glyphosate, may antagonize the control efficacy of glyphosate. So it is very important to find out a way to relieve or eliminate the antagonistic effect of manganese to glyphosate. The purpose of present study is to investigated the relieving effect of gibberellin A₃(GA₃) on antagonism of manganese to glyphosate in Festuca elata by spraying mixture of glyphosate and manganese and GA₃. The results indicated that spraying GA₃ in tank mixtures with glyphosate and manganese could make the leaf color of Festuca elata more yellow and increase the leaf wilting to some extent when compared with that spraying the mixture of glyphosate and manganese; and the toxic symptom of Festuca elata is similar with that spraying glyphosate alone; GA₃ at 50 mg/L showed the best relieving effect.After foliar spray of GA₃ in tank mixtures with glyphosate and manganese, the fresh weight,plant height and chlorophyll content of Festuca elata decreased greatly while shikimate acid content and MDA accumulation in leaves increased significantly.In comparison with glyphosate and Mn²⁺ mixture treated plants, the content of leaf shikimate acid saw an obvious climbing trend in GA₃-contained groups, which raised 49.8% (50 mg/L GA₃) and 28.8% (30 mg/L GA₃) on the 6^th day after spraying. In addition, contents of MDA in plants also significantly increased (54.1%, 50 mg/L GA₃ and 52.9%, 30 mg/L GA₃) after 2^th day of GA₃-contained spray treatments.The results suggested that foliar spray of GA₃ in tank mixtures with manganese fertilizer and glyphosate will largely alleviate the antagonism of manganese to glyphosate and ensure the control efficacy of glyphosate to weeds.