Weekes Rebecca, Allnutt Theodore, Boffey Caroline, Morgan Sarah, Bilton Mark, Daniels Roger, Henry Christine
Central Science Laboratory, Sand Hutton, York, YO41 1LZ, UK.
Transgenic Res. 2007 Apr;16(2):203-11. doi: 10.1007/s11248-006-9036-0. Epub 2006 Nov 11.
From 2000 to 2003 a range of Farm Scale Evaluation (FSE) trials were established in the UK to assess the effect of the release and management of herbicide tolerant (HT) crops on arable weeds and invertebrates. The FSE trials for maize were also used to investigate crop-to-crop gene flow and to develop a statistical model for the prediction of gene flow frequency that can be used to evaluate current separation distance guidelines for GM crops. Seed samples were collected from the non-GM half of 55 trial sites and 1,055 were tested for evidence of gene flow from the GM HT halves using a quantitative PCR assay specific to the HT (pat) gene. Rates of gene flow were found to decrease rapidly with increasing distance from the GM source. Gene flow was detected in 30% of the samples (40 out of 135) at 150 m from the GM source and events of GM to non-GM gene flow were detected at distances up to and including 200 m from the GM source. The quantitative data were subjected to statistical analysis and a two-step model was found to provide the best fit for the data. A dynamic whole field model predicted that a square field (150 m x 150 m in size) of grain maize would require a separation distance of 3 m for the adjacent crop to be below a 0.9% threshold (with <2% probability of exceeding the threshold). The data and models presented here are discussed in the context of necessary separation distances to achieve various possible thresholds for adventitious presence of GM in maize.
2000年至2003年期间，英国开展了一系列农场规模评估（FSE）试验，以评估耐除草剂（HT）作物的释放和管理对耕地杂草及无脊椎动物的影响。玉米的FSE试验还用于研究作物间的基因流动，并建立一个统计模型来预测基因流动频率，该模型可用于评估当前转基因作物的隔离距离指导原则。从55个试验点的非转基因区域采集了种子样本，共1055份，使用针对HT（pat）基因的定量PCR检测法，检测样本中是否有来自转基因HT区域的基因流动证据。研究发现，基因流动速率随着与转基因源距离的增加而迅速降低。在距离转基因源150米处的样本中，30%（135份中的40份）检测到基因流动，在距离转基因源达200米（含200米）处检测到了转基因向非转基因的基因流动事件。对定量数据进行了统计分析，发现两步模型最适合这些数据。一个动态全场模型预测，对于一块面积为150米×150米的谷物玉米方形田地，相邻作物要低于0.9%的阈值（超过该阈值的概率<2%），所需的隔离距离为3米。本文介绍的数据和模型是在实现玉米中转基因偶然存在的各种可能阈值所需的隔离距离背景下进行讨论的。
