不同种植年限转基因抗虫棉对土壤中小型节肢动物的影响

EFFECTS OF TRANSGENIC INSECT-RESISTANT COTTON PLANTS DIFFERENT IN PLANTING AGE ON SOIL MESO-AND MICRO ARTHROPODS

2007-2008年,在分别于1999年、2002年和2006年种植Cry1Ac基因抗虫棉的棉田中,于棉花的苗期、蕾期、花铃期和吐絮期采集土壤样品,采用改良的Tullgren法收集土壤中的中小型节肢动物,以监测长期种植转基因抗虫棉对土壤节肢动物群落的影响。2年8次采样共获得12类中小型节肢动物,隶属于节肢动物门中的7纲10目,其中弹尾目、蜱螨目、蜘蛛目为本地区棉田中的优势类群,综合纲、双翅目、半翅目、双尾目、鞘翅目和同翅目为常见类群。广义线性混合模型分析结果表明,随着转基因抗虫棉种植年限的增加,各转基因抗虫棉田中的土壤主要类群中小型节肢动物的个体密度和多样性指数没有产生显著性差异,但是随着采样时期的不同各棉田土壤主要中小型节肢动物的个体密度和群落多样性指数均呈显著性季节变化。主成分分析表明,弹尾目、蜘蛛目、蜱螨目的得分值较高,可作为本地区未来转基因抗虫棉环境影响监测的重要指标生物。

In the consecutive 2-year field study（2007-2008）,we took soil samples at four different cotton growth stages,namely,seedling,budding,boll forming and boll opening stages from cotton fields that had been planted with Cry1Ac cottons separately since 1999,2002 and 2006,and collected soil meso-and microarthropodas in the samples with the modified Tullgren method,to monitor environmental impact of long-term cultivation of transgenic insect-resistant cotton in field conditions.A total of 12 taxonomic groups of soil meso-and microarthropods were obtained from soil samples collected in 8 times during the 2 years and could be further sorted into 7 classes,and 10 orders under arthropodas phyla.Collembola,Acarina and Araneida were the dominant groups and Symphyla,Diptera,Hemiptera,Diplura,Coleoptera and Homoptera were the common groups in the soil.The Generalized Linear Mixed Model（GLMM） analysis of the 2-year data on soil arthropods shows that no significant difference was found between cotton fields different in cultivation age in individual number and the community diversity indices of the soil meso-and microarthropodas of the main soil arthropod groups,but significant seasonal variation was observed in the individual numbers and the diversity indices of the main soil meso-and microarthropodas.The Principal Component Analysis suggested that Collembola,Acarina and Araneida were relatively higher in value and can be cited as important indicator organisms to monitor environmental impacts of transgenic plants in the future in this region.