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Abstract：
Brassica rapa L. is an annual Brassicaceae species cultivated for oil and food production, whose wild form is a weed of crops worldwide. In temperate regions of South America and especially in the Argentine Pampas region, this species is widely distributed. During 2014, wild B. rapa populations that escaped control with glyphosate applications by farmers were found in this area. These plants were characterized by morphology and seed acidic profile, and all the characters agreed with B. rapa description. The dose-response assays showed that the biotypes were highly resistant to glyphosate. It was also shown that they had multiple resistance to AHAS-inhibiting herbicides. The transgenic origin of the glyphosate resistance in B. rapa biotypes was verified by an immunological test which confirmed the presence of the CP4 EPSPS protein and by an event-specific GT73 molecular marker. The persistence of the transgene in nature was confirmed for at least 4 years, in ruderal and agrestal habitats. This finding suggests that glyphosate resistance might come from GM oilseed rape crops illegally cultivated in the country or as a seed contaminant, and it implies gene flow and introgression between feral populations of GM B. napus and wild B. rapa. The persistence and spread of the resistance in agricultural environments was promoted by the high selection pressure imposed by intensive herbicide usage in the prevalent no-till farming systems.
摘要：
甘蓝型油菜是一年生的十字花科物种，用于石油和粮食生产，其野生形式是全世界农作物的杂草。在南美洲的温带地区，尤其是在阿根廷的潘帕斯地区，该物种分布广泛。2014年，在该地区发现了野生B.rapa种群，这些种群逃脱了农民对草甘膦的控制。这些植物的特征在于形态和种子酸性特征，所有角色都同意B.rapa的描述。剂量反应试验表明，生物型对草甘膦具有高度抗性。还显示它们对抑制AHAS的除草剂具有多重抗性。通过确认CP4EPSPS蛋白的存在的免疫学测试和通过事件特异性GT73分子标记来验证B.rapa生物型中草甘膦抗性的转基因起源。转基因在自然界中的持久性得到证实至少4年，在ruderal和agrestal栖息地。这一发现表明，草甘膦抗性可能来自在该国非法种植的转基因油菜作物或作为种子污染物，它暗示了转基因油菜野生种群和野生油菜种群之间的基因流动和基因渗入。在普遍的免耕耕作系统中，大量使用除草剂施加的高选择压力促进了抗性在农业环境中的持久性和传播。
