中文摘要：东方鸭茅状磨擦禾与玉米同属禾本科植物，且自然生长于美国商业化玉米种植的区域。尽管没有证据证明自然界中玉米与东方鸭茅状磨擦禾间存在基因流动，但运用特定技术可以完成两个物种的杂交实验。作为环境风险评估的一部分，本文研究了自然条件下玉米到东方鸭茅状磨擦禾基因流动的可能性，分别（1）研究自然生长在转基因耐草甘膦玉米周围的东方鸭茅状磨擦禾种子来揭示两个物种间的杂交授粉；（2）评估转基因玉米雄株与东方鸭茅状磨擦禾雌株种间杂交的可能性。研究发现，尽管东方鸭茅状磨擦禾生长转基因耐草甘膦玉米周围多年，但经过除草剂没有东方鸭茅状磨擦禾幼苗能成活且其种子都不含耐草甘膦的转基因；在135个人工授粉的样本中均没有产出种间杂交种子。研究结果表明，在自然栖息地没有发现从转基因玉米到东方鸭茅状磨擦禾的基因流动。因而在评估转基因玉米对野生近缘种基因流动的环境风险时，应考虑到本研究的结果。
 
外文摘要：Eastern gamagrass (Tripsacum dactyloides L.) belongs to the same tribe of the Poaceae family as maize (Zea mays L.) and grows naturally in the same region where maize is commercially produced in the USA. Although no evidence exists of gene flow from maize to eastern gamagrass in nature, experimental crosses between the two species were produced using specific techniques. As part of environmental risk assessment, the possibility of transgene flow from maize to eastern gamagrass populations in nature was evaluated with the objectives: (1) to assess the seeds of eastern gamagrass populations naturally growing near commercial maize fields for the presence of a transgenic glyphosate-tolerance gene (cp4 epsps) that would indicate cross-pollination between the two species, and (2) to evaluate the possibility of interspecific hybridization between transgenic maize used as male parent and eastern gamagrass used as female parent. A total of 46,643 seeds from 54 eastern gamagrass populations collected in proximity of maize fields in Illinois, USA were planted in a field in 2014 and 2015. Emerged seedlings were treated with glyphosate herbicide and assessed for survival. An additional 48,000 seeds from the same 54 eastern gamagrass populations were tested for the presence of the cp4 epsps transgene markers using TaqMan(A (R)) PCR method. The results from these trials showed that no seedlings survived the herbicide treatment and no seed indicated presence of the herbicide tolerant cp4 epsps transgene, even though these eastern gamagrass populations were exposed to glyphosate-tolerant maize pollen for years. Furthermore, no interspecific hybrid seeds were produced from 135 hand-pollination attempts involving 1529 eastern gamagrass spikelets exposed to maize pollen. Together, these results indicate that there is no evidence of gene flow from maize to eastern gamagrass in natural habitats. The outcome of this study should be taken in consideration when assessing for environmental risks regarding the consequence of gene flow from transgenic maize to its wild relatives.
外文关键词：Eastern gamagrass; Transgenic maize; Gene flow; Glyphosate-tolerance
作者： Lee, Moon-Sub; Anderson, Eric K.; Stojsin, Duska; 等.
作者单位：Univ Illinois
期刊名称：TRANSGENIC RESEARCH
期刊影响因子：2.341
出版年份：2017
出版刊次：8
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