转基因抗草甘膦抗虫棉对棉田冠层节肢动物群落的影响

【背景】随着转基因抗虫棉在我国的广泛种植，一种具有抗虫和耐除草剂（草甘膦）的双价棉被培育成功。这种转双价基因棉和转单价基因抗虫棉对棉田节肢动物群落结构的影响可能不同。因此，在该类转双价基因棉花进行环境释放之前，有必要研究其对棉田节肢动物群落的影响，评价其环境安全性。【方法】试验于2010年5月9日~9月23日和2011年5月10日~9月24日在河南省安阳市中国农业科学院棉花研究所试验农场进行，棉田类型有3种——转基因抗草甘膦抗虫棉田、转Bt棉田和常规棉田，每种棉田种植3个小区，每个小区面积为200 m2（8 m×25 m）。采用对角线5点取样方法，每5 d调查1次棉田的节肢动物群落，通过目测对节肢动物鉴定到属。【结果】抗草甘膦抗虫棉田、Bt棉田和常规棉田节肢动物群落、害虫亚群落和天敌亚群落的结构与组成无明显差异；抗草甘膦抗虫棉田害虫种群数量低于抗虫棉田和常规棉田，而其天敌种群数量与常规棉田相当，略低于Bt棉田；3种棉田节肢动物群落、害虫亚群落和天敌亚群落的多样性指数、均匀性指数均无明显差异。【结论与意义】种植转基因抗草甘膦抗虫棉花不会对棉田节肢动物群落组成造成显著影响。本研究为转基因抗草甘膦抗虫棉田的环境安全性评价提供了依据。

Effects of transgenic glyphosate-insect resistant cotton on arthropod communities in cotton fields in Henan Province, east central China

【Background】After the widespread adoption of trangenic insect resistant cotton in China, a double-gene transgenic cotton was developed that confers resistance to the herbicide glyphosate. The overall impact of such multiple constructs could be different from their single-gene equivalent, thus field studies on the effects of this double-gene cotton on arthropod communities should be carried out as part of the pre-release biosafety evaluations. 【Method】We did a visual survey of the arthropod communities in transgenic glyphosate-insect resistant cotton, Bt transgenic cotton and non-transgenic cotton plots, planted on the research farm of the Cotton Research Institute of the Chinese Academy of Agricultural Sciences in Anyang, Henan Province. The survey was carried on every other five days by the method of five point sampling from May 9 to September 23, 2010, and May 10 to September 24, 2011. Each cotton cultivar was planted on three separate plots of 200 m2 （8 m×25 m）. Arthropods were visually identified to genus. 【Result】There were no significant differences in the structure and composition of arthropod community, pest sub-community and natural enemy sub-community among the three cotton fields. The observed number of pest arthropods in glyphosate-insect resistant cotton were lower than in Bt- or and non-transgenic cotton. The overall numbers of natural enemies in the double-gene transgenic cotton were equal to the non-transgenic one and lower than in Bt cotton. The values of the biological diveristy index and the evenness indexes of the arthropod communities, pest or natural enemy sub-communities showed no significant differences among the three cotton fields. 【Conclusion and significance】It seems that the planting of transgenic glyphosate insect resistant cotton causes no drastic rearrangement in the composition of the arthropod communities. This study will make help for the assessment of environment safety of transgenic glyphosate insect resistant cotton.