转基因抗草甘膦抗虫棉的荒地生存竞争能力

Survival of transgenic glyphosate-and insect-resistant cotton in non-cultivated land

【背景】随着转基因作物的大量种植,其环境安全性已成为目前的研究热点,其中转基因作物的荒地生存竞争能力,是其环境安全性评价的重要内容之一。【方法】以2种转双价抗草甘膦抗虫基因(EPSPS+cry1Ac)棉为试验品种,非转基因棉中棉所49为对照品种,分别于4月底和5月底在荒地用地表撒播和3cm深播2种方式播种,并于4～9月份对棉花存活率、株高、真叶数、茎直径、果枝数、蕾铃数等生长参数进行比较,以检测、评价其荒地竞争能力及杂草化风险。【结果】无论是撒播还是深播,荒地中棉花长势均较弱,表现为生长缓慢、植株矮小、生育期延迟。4月底播种的棉花有极个别植株能够结铃,但铃数极少且小,无成熟的种子;5月底播种的棉花长势更弱,至9月底未见蕾铃。【结论与意义】转基因抗草甘膦抗虫棉在荒地中无竞争优势,不能繁殖传代,无杂草化风险。本研究为转基因棉花环境安全评价技术的完善提供了理论依据。

[ Background] Safety assessment of transgenic crop plants has been a concern, and only limited knowledge can be obtained from pre-release experiments. Once released, the survival and competitiveness of transgenic crops in non-cultivated land is one of the most important safety concerns. [ Method ] We tested three transgenic cotton cultivars, two double-constrnct transgenic glyphosate- and insect-resistant cotton cuhivars, and one non-transgenic cotton （ CCRI 49）, which was the isogenic control. Seeds were scattered on the soil surface, or planted 3 em deep in late April and late May. We compared the growth parameters among the examined cotton varieties monthly from April to September, including survival rate, plant height, leaf number, stem diameter, sym- podial branch number, bud and boll numbers, in order to test and evaluate their competitiveness on non-cultivated land and the risk of weediness. [ Result ] Transgenic glyphosate- and insect-resistant cotton in wasteland was weak and stunted with slow and retarded growth. Only a few individuals sown in late April could produce a few small bolls; these were without mature seeds. Plants sown in late May were weaker, and no bud appeared until late September. [ Conclusion and significance] Transgenic glyphosate- and insect- resistant cotton had no competitive advantage and limited reproductive capacity on non-cultivated land, and consequently, low weed- iness potential.