Zapiola María Luz, Mallory-Smith Carol Ann
Department of Crop and Soil Science, Oregon State University, Corvallis, Oregon, United States of America.
PLoS One. 2017 Mar 3;12(3):e0173308. doi: 10.1371/journal.pone.0173308. eCollection 2017.
The planting of 162 ha of transgenic glyphosate-resistant creeping bentgrass (Agrostis stolonifera) near Madras, OR, USA, allowed a unique opportunity to study gene flow over time from a perennial outcrossing species at the landscape level. While conducting a four year in situ survey, we collected panicles and leaf tissue samples from creeping bentgrass and its sexually compatible species. Seeds from the panicles were planted, and seedlings were tested in the greenhouse for expression of the transgene. Gene flow via pollen was found in all four years, at frequencies of 0.004 to 2.805%. Chloroplast markers, in combination with internal transcribed spacer nuclear sequence analysis, were used to aid in identification of transgenic interspecific and intergeneric hybrid seedlings found during the testing and of established plants that could not be positively identified in the field. Interspecific transgenic hybrids produced on redtop (Agrostis gigantea) plants in situ were identified three of the four years and one intergeneric transgenic creeping bentgrass x rabbitfoot grass (Polypogon monspeliensis) hybrid was identified in 2005. In addition, we confirmed a non-transgenic creeping bentgrass x redtop hybrid in situ, demonstrating that interspecific hybrids have established in the environment outside production fields. Results of this study should be considered for deregulation of transgenic events, studies of population dynamics, and prediction of gene flow in the environment.
在美国俄勒冈州马德拉斯附近种植了162公顷转基因抗草甘膦匍匐翦股颖（Agrostis stolonifera），这为在景观层面研究多年生异交物种随时间的基因流动提供了一个独特的机会。在进行为期四年的实地调查时，我们从匍匐翦股颖及其有性亲和物种中采集了圆锥花序和叶片组织样本。将圆锥花序的种子种下，幼苗在温室中进行转基因表达测试。在所有四年中均发现了通过花粉的基因流动，频率为0.004%至2.805%。叶绿体标记与内部转录间隔区核序列分析相结合，有助于鉴定测试期间发现的转基因种间和属间杂交幼苗以及在田间无法明确鉴定的已定植植株。在四年中的三年里，在原地红顶草（Agrostis gigantea）植株上产生的种间转基因杂种被鉴定出来，2005年鉴定出一个属间转基因匍匐翦股颖×兔尾草（Polypogon monspeliensis）杂种。此外，我们在原地确认了一个非转基因匍匐翦股颖×红顶草杂种，表明种间杂种已在生产田以外的环境中定植。本研究结果应在转基因事件的解除管制、种群动态研究以及环境中基因流动预测方面予以考虑。
