除草剂对抗草甘膦大豆光合作用和蒸腾作用的影响

本试验采用随机区组的设计方法，在花荚期喷施不同浓度的农达和草甘膦10％水剂，研究了两种不同水剂、不同浓度的草甘膦对抗草甘膦大豆RR2光合作用和蒸腾作用的影响。结果表明：农达和草甘膦10％水剂均使RR2的叶绿素含量和光合速率下降，但草甘膦10％水剂的抑制作用更明显；农达可以增加RR2的气孔导度和蒸腾速率；草甘膦10％水剂却使RR2气孔导度和蒸腾速率先增加后降低，但是各浓度下的蒸腾速率均低于对照。叶绿素含量与光合速率的变化趋势一样，气孔导度与蒸腾速率的变化趋势一样。结果还表明，草甘膦对抗草甘膦大豆并非绝对安全，在超过一定剂量时就会对抗草甘膦大豆造成伤害，影响其生理代谢；即使除草剂有效成分相同。剂型不同也会对药效产生差异。

Effect of Herbicides on Photosynthesis and Transpiration of Glyphosate-Resistant Soybean

Randomized complete block experimental design was used in the trial.Different dosage of Roundup41% aqua and Glyphosate10% aqua were sprayed during flowering and podding periods,and chlorophyll content,stomatal conductance,transpiration rate and photosynthetic rate of glyphosate-resistant soybean(RR2) were monitored.The results showed that chlorophyll content,net photosynthetic rate(Pn) decreased with increasing the dosage of Roundup41% aqua and Glyphosate 10% aqua,while the repressive effect of Glyphosate10% aqua was more obvious than that of Roundup41% aqua;Roundup41% aqua could increase the stomatal conductance and transpiration rate of RR2;Glyphosate 10% aqua increased the stomatal conductance and transpiration rate of RR2 at low dosage,but decreased at high dosage,while transpiration rate at each dosage was lower than the check.The change trend of chlorophyll content and photosynthetic rate were similar,the same as that of stomatal conductance and transpiration rate.The results also indicated that glyphosate is not absolutely safe to glyphosate-resistant soybean,the dosage of herbicide should not be increased at will.Though the main ingredient is the same,the differences caused by herbicide formulation should be considered.