转cry1Ac／cpti基因水稻对土壤酶活性和养分有效性的影响

【背景】转基因作物可能通过根系分泌物和植株残体组成的改变对土壤酶活性和养分转化产生影响，转基因作物对土壤质量的影响是其环境安全性评价的重要方面。【方法】本研究通过田间定位试验分析了连续3a种植2种转crylAc／cpti双价抗虫基因水稻后，土壤酶活性和养分有效性等土壤质量性状的变化。【结果】在水稻各生育期内，除齐穗期转基因稻科丰8号（GM1）田的土壤酸性磷酸酶活性显著（P〈0．05）高于其受体非转基因稻明恢86（CK1）外，转基因稻GM1、GM2（Ⅱ优科丰8号）的土壤酸性磷酸酶、碱性磷酸酶和脲酶活性与对应非转基因稻CK1、CK2（Ⅱ优明恢86）间均无显著差异。同时，在水稻生长过程中，土壤pH、有机质、有效氮、有效磷和速效钾等土壤理化指标在GM1和CK1或GM2和CK2间也均无显著差异。【结论与意义】连续38种植转crylAc／cpti双价抗虫基因水稻并未改变稻田土壤中主要营养元素的有效性及其相关土壤酶活性，即短期内种植转crylAc／cpti双价抗虫基因水稻不会影响土壤酶活性和养分状况。该结果为进一步评价转基因水稻的生态风险提供了一定的依据。

Effect of cry1Ac/cpti transgenic rice on enzyme activity and nutrient availability in paddy soil

Background] The cultivation of genetically modified （GM） plants may have the potential to alter the activity of soil en- zymes or the availability of soil nutrient through root exudates and plant residues. The influence of transgenic plants on soil quality is an important aspect of the environmental risks assessments of GM crops. Method] In this study, two lines of transgenic rice contai- ning the crylAc/cpti construct （Bt toxin and cowpea trypsin inhibitor genes） （GM1 and GM2） and their parental non-transgenic rice （CK1 and CK2） were planted in the same field site for three years. Soil enzyme activity and soil nutrient availability in the field site were analyzed in the third year. Result] The activity of acid phosphatase in soil under GM1 in heading was significantly （P 〈 0.05） higher than that of CK1. There were no other differences between GM1 and CK1 or between GM2 and CK2 in the activity lev- eles of acid phosphatase, alkaline phosphatase and urease in the paddy soil during the rice growth seasons. At the same time, soil pH, organic C and availability of nitrogen, phosphorus and potassium in the paddy soil under GM1 or GM2 were similar to those of CK1 or CK2. Conclusion and significance J The crylAc/cpti transgenic rice did not seem to have major effects on mineralization of major soil nutrients and corresponding soil enzyme activities, and planting the cryl Ac/cpti transgenic rice did not damage the activity of soil enzyme and nutrien cycling, at least in short tenn.