棉田反枝苋和马齿苋对草甘膦的抗药性

为明确棉田反枝苋和马齿苋对草甘膦的抗性水平,采用培养皿种子法和整株检测法分别测定了7个省18个采样点反枝苋、马齿苋的抗性水平,并采用紫外分光光度计测定采样点反枝苋、马齿苋体内莽草酸含量变化的差异。结果表明:采样点地区的反枝苋和马齿苋对草甘膦存在不同程度的抗药性,2种监测法的抗性趋势基本一致,其中陕西西安采样点的反枝苋和新疆疏勒采样点的马齿苋处于敏感水平,河北曲周采样点的反枝苋抗性倍数最高。植物体内莽草酸积累变化与植物抗性水平相关,抗性较低的植物体内莽草酸积累量普遍高于抗性较高的植物。

Resistance of Amaranthus retroflexus and Portulaca oleracea to Glyphosate in Cotton Fields

To investigate the resistance of Amaranthus retroflexus and Portulaca oleracea to glyphosate, 18 collection sites were selected from cotton fields in seven provinces, and then the level of resistance of these two weed species to glyphosate was evaluated by seed and whole plant bioassays. Additionally, differences of shikimic acid content in A. retroflexus and P. oleracea were measured by ultraviolet spectrophotometry. The results showed that A. retroflexus and P. oleracea from different collection sites had different levels of resistance to glyphosate, and the two detection methods showed the same resistance tendency. A. retroflexus from the collection site of Xi'an, Shaanxi and P. oleracea from Shule, Xinjiang were the most sensitive to glyphosate. The highest resistance level for both A. retroflexus were found in plants from the collection site of Quzhou, Hebei. The shikimic acid content in the plants was associated with their resistance level; in general, less resistant plants accumulated more shikimic acid than more resistant ones.