Toothpick test: a methodology for the detection of RR soybean plants1

Due to the large increase in the area cultivated with genetically modified soybean in Brazil, it has become necessary to determine methods that are fast and efficient for detecting these cultivars. The aim of this work was to test the efficiency of the toothpick method in the detection of RR soybean plants, as well as to distinguish between cultivars, for sensitivity caused by herbicide. Ten transgenic soybean cultivars, resistant to the active ingredient glyphosate, and ten conventional soybean cultivars were used. Toothpicks soaked in glyphosate were applied to all the plants at stage V6 and evaluations were made at 2, 4, 6, 8 and 10 days after application (DAA). The effects of the glyphosate on the cultivars, and the symptoms of phytotoxicity caused in the transgenic plants were evaluated by means of grading scales. The toothpick test is effective in identifying RR soybean cultivars and also in separating them into groups by sensitivity to the symptoms caused by the glyphosate.

鉴于巴西转基因大豆种植面积大幅扩张，亟需研发快速高效的该类品种检测方法。本研究旨在验证牙签法检测抗草甘膦大豆（RR soybean）植株的有效性，并区分不同品种对除草剂的敏感性差异。实验共选用10个耐草甘膦活性成分的转基因大豆品种，以及10个常规大豆品种。于大豆V6生育期，向所有植株施加浸有草甘膦的牙签，并分别于施药后2、4、6、8、10天（Days After Application，DAA）开展评价。通过分级评分体系，评估草甘膦对各品种的影响以及转基因植株所产生的药害症状。结果显示，牙签法可有效识别抗草甘膦大豆品种，并能依据品种对草甘膦诱导药害症状的敏感性进行分组归类。