Arnaud J-F, Viard F, Delescluse M, Cuguen J
UMR CNRS 8016, Laboratoire de Génétique et Evolution des Populations Végétales, Bâtiment SN2, Universitéde Lille 1, 59655 Villeneuve d'Ascq cedex, France.
Proc Biol Sci. 2003 Aug 7;270(1524):1565-71. doi: 10.1098/rspb.2003.2407.
Gene flow and introgression from cultivated to wild plant populations have important evolutionary and ecological consequences and require detailed investigations for risk assessments of transgene escape into natural ecosystems. Sugar beets (Beta vulgaris ssp. vulgaris) are of particular concern because: (i) they are cross-compatible with their wild relatives (the sea beet, B. vulgaris ssp. maritima); (ii) crop-to-wild gene flow is likely to occur via weedy lineages resulting from hybridization events and locally infesting fields. Using a chloroplastic marker and a set of nuclear microsatellite loci, the occurrence of crop-to-wild gene flow was investigated in the French sugar beet production area within a 'contact-zone' in between coastal wild populations and sugar beet fields. The results did not reveal large pollen dispersal from weed to wild beets. However, several pieces of evidence clearly show an escape of weedy lineages from fields via seed flow. Since most studies involving the assessment of transgene escape from crops to wild outcrossing relatives generally focused only on pollen dispersal, this last result was unexpected: it points out the key role of a long-lived seed bank and highlights support for transgene escape via man-mediated long-distance dispersal events.
栽培植物种群与野生植物种群之间的基因流动和基因渗入具有重要的进化和生态后果，需要进行详细调查，以评估转基因逃逸到自然生态系统中的风险。甜菜（Beta vulgaris ssp. vulgaris）尤其值得关注，原因如下：（i）它们与其野生近缘种（海甜菜，B. vulgaris ssp. maritima）杂交亲和；（ii）作物到野生植物的基因流动很可能通过杂交事件产生的杂草谱系发生，并在当地侵扰农田。利用一个叶绿体标记和一组核微卫星位点，在法国甜菜产区沿海野生种群和甜菜田之间的“接触区”，对作物到野生植物的基因流动情况进行了调查。结果并未显示出从杂草到野生甜菜的大量花粉传播。然而，有几条证据清楚地表明，杂草谱系通过种子传播从农田逃逸。由于大多数涉及评估转基因从作物逃逸到野生异交近缘种的研究通常只关注花粉传播，所以这一最新结果出人意料：它指出了长期种子库的关键作用，并突出了对通过人类介导的远距离传播事件导致转基因逃逸的支持。
