Dpto. Agronomía, Universidad Nacional del Sur (UNS), San Andrés 800, 8000, Bahía Blanca, Argentina.
Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS), Universidad Nacional del Sur-CONICET, Camino La Carrindanga Km 7, 8000, Bahía Blanca, Argentina.
Environ Sci Pollut Res Int. 2018 Mar;25(7):6251-6264. doi: 10.1007/s11356-017-0726-3. Epub 2017 Dec 14.
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.
芸薹属植物（Brassica rapa L.）是一种一年生十字花科物种，主要用于油类和食品生产，其野生形式是全世界农作物的杂草。在南美洲的温带地区，特别是在阿根廷潘帕斯地区，该物种广泛分布。2014 年，在该地区发现了农民使用草甘膦控制后逃脱的野生芸薹属植物种群。这些植物的形态和种子酸性特征表明它们是芸薹属植物，所有特征均符合芸薹属植物的描述。剂量反应试验表明，这些生物型对草甘膦具有高度抗性。此外，它们对 AHAS 抑制性除草剂也具有多重抗性。通过免疫检测证实了 CP4 EPSPS 蛋白的存在，并通过特定事件的 GT73 分子标记证实了草甘膦抗性源自转基因，从而验证了芸薹属植物生物型中草甘膦抗性的转基因起源。在自然条件下，至少在 4 年内，在野生和半野生生境中，该转基因仍能持续存在。这表明，草甘膦抗性可能来自该国非法种植的转基因油菜作物或作为种子污染物，这意味着基因流和转基因 B. napus 与野生 B. rapa 之间的渐渗。由于普遍采用免耕农业系统，高强度的除草剂使用造成了强烈的选择压力，从而促进了这种抗性在农业环境中的持久性和传播。
