施用草甘膦对转基因抗除草剂大豆田杂草防除、大豆安全性及杂草发生的影响

【目的】转GAT和EPSPS双价基因抗草甘膦大豆‘GE-J16’是我国具有自主知识产权的抗除草剂材料,喷施草甘膦后,评价草甘膦对杂草防除、大豆安全和杂草发生的影响,为其将来商业化种植后的安全监测与杂草治理提供数据支持。【方法】除草效果:每小区以对角线5点取样法取5个0.25 m2样点并标记,施药后28 d调查禾本科和阔叶杂草株数,并剪取地上部分称取鲜重,计算株防效和鲜重防效。对大豆安全性:每小区以对角线5点取样法,每点随机取4株大豆并标记,在喷药当天、药后7、14、21及28 d调查大豆株高和复叶数,观察药害,收获前每小区取50株大豆调查结荚数及产量。杂草发生情况:每小区以对角线5点取样法取5个0.25 m2样点并标记(避开除草效果取样点),调查并记录每种杂草种类、株数,计算每种杂草相对多度。【结果】转基因大豆喷施900、1 800和3 600 g a.i./hm2草甘膦对禾本科杂草株防效2016年分别为84.30%、95.22%和83.62%,阔叶杂草株防效分别为49.80%、64.52%和61.93%,禾本科和阔叶杂草鲜重防效分别在95.36%和82.05%以上,2017年对禾本科...

Effects of Glyphosate on Weed Control,Soybean Safety and Weed Occurrence in Transgenic Herbicide-Resistant Soybean

【Objective】 Transgenic soybean ‘GE-J16’ that co-expressed with GAT and EPSPS conferring resistance to glyphosate, is a herbicide-resistant (HR) variety in China with independent intellectual property. The objective of this study is to evaluate the effect of glyphosate application on weed control, soybean safety, and weed occurrence in glyphosate-resistant (GR) soybean ‘GE-J16’, and to provide the basic data for HR crops’ safety monitoring after commercial planting and weed management strategies.【Method】For weed control, in each soybean plot, 5 sample points were chosen along a diagonal and 0.25 m ²was tagged as one sample point, 28 days after glyphosate application (DAG), the numbers of grassy and broadleaf weeds were surveyed and the above-ground parts were cut to get fresh weight, then weed control efficacy was calculated by fresh weight and weed number. For soybean safety, in each soybean plot, 5 sample points were chosen along a diagonal and 4 soybean plants were tagged with random selection in one sample point. The plant height and compound leaf number were investigated on the day of spraying, 7, 14, 21, and 28 DAG, separately. At the same time, herbicide damage of plants was visually observed. Before harvest, 50 soybean plants were collected from each plot, pod number of each plant and yield of 50 plants were tested. For weed occurrence, in each soybean plot, 5 sampling points were chosen along a diagonal and 0.25 m ²was tagged as one sample point. All selected sampling points were different from those sampling points of weed control. The number and type of each weed species were counted in each sampling point. For each species of weeds, relative abundance (RA) was calculated.【Result】In 2016, at the glyphosate application doses of 900, 1 800 and 3 600 g a.i./hm ², the plant control efficacy of grassy and broadleaf weeds was 84.30%, 95.22%, 83.62%, and 49.80%, 64.52%, 61.93%, respectively. The fresh weight control efficacy of grassy and broadleaf weeds was above 95.36% and 82.05%, respectively. In 2017, at the same glyphosate application doses, the plant control efficacy of grassy and broadleaf weeds was above 94.93% and 85.09%, respectively. The fresh weight control efficacy of grassy and broadleaf weeds was above 98.00% and 96.57%, respectively. Glyphosate did not affect plant growth after application and soybean yield of different glyphosate treatments was higher than that of hand weeding treatment. Two years of short-term experimental research showed that weed species shifted in transgenic GR soybean after glyphosate application. The weed flora was dominated by six species including broadleaf weeds Amaranthus retroflexus, Calystegia hederacea, Portulaca oleracea, and grassy weeds Setaria viridis, Digitaria sanguinalis, and Eleusine indica in GR soybean without weeding, while in GR soybean sprayed with glyphosate at 900 to 3 600 g a.i./hm ², the weed flora was dominated by C. hederacea, Lagopsis supina, P. oleracea, E. indica, and S. viridis.【Conclusion】Glyphosate at 900-3 600 g a.i./hm ² has a good weed control efficacy in transgenic GR soybean ‘GE-J16’, and it is safe for soybean ‘GE-J16’. Thus, transgenic soybean ‘GE-J16’ has great potential for application in China in the future. The weed species shift in GR soybean after glyphosate application, and it will be needed to monitor for a long time if transgenic soybean is permitted to plant in China.