种植转双价基因(Bt＋CpTI)棉对主要土壤养分和酶活性的影响

Effects of Transgenic Bt+CpTI Cotton Planting on the Soil Main Nutrients and Enzyme Activities

采用灭菌盆栽试验,以转双价棉品种sGK321及其亲本常规棉品种石远321为研究对象,对4个生长时期(苗期、蕾期、花铃期、吐絮期)根际土壤养分(全氮、全磷、速效磷和有机质)含量及某些酶(脲酶、碱性磷酸酶和过氧化氢酶)活性变化进行了对比分析。结果表明,在观测期间,与同源常规棉相比,转双价棉根际土壤全磷含量和速效磷含量在同一时期均无显著差异,不同生育期差异明显,根际土壤全氮含量、有机质含量、酶活性在一些时期则明显不同,其变化随棉花品种、生育期不同而不同。转双价棉蕾期根际土壤全氮含量和苗期根际土壤过氧化氢酶活性以及苗期、蕾期的碱性磷酸酶活性显著高于常规棉(P<0.05),而蕾期根际土壤有机质含量、根际土壤过氧化氢酶活性和苗期、花铃期根际土壤脲酶活性以及苗期碱性磷酸酶活性则显著低于常规棉(P<0.05)。聚类分析表明,土壤养分和酶活性变化主要受生长时期的影响,转双价棉种植对其影响是非常有限的。

A pot experiment compared transgenic Bt＋CpTI cotton cultivar sGK321 with conventional cotton cultivar Shiyuan 321 （check） to investigate the effects of nutrients in rhizosphere soil （total nitrogen, total phosphorus, available phosphorus, organic matter） and the activities of some enzymes （urease, alkaline phosphatase, and catalase） in four growing stages（seedling, budding, flower and boll, boll opening）. Results showed that there were no significant differences between the two cotton cultivars in total and available phosphorus in rhizosphere soil during the experimental period. Remarkable differences, however, existed between the transgenic Bt＋CpTI cotton cultivar and its conventional check in terms of total nitrogen, organic matter, and enzyme activity in rhizosphere soil. For transgenic Bt＋CpTIcotton, total nitrogen at the budding stage, catalase activity at the seedling stage, and alkaline phosphatase activity at the seedling and budding stages were significantly higher than its conventional check Shiyuan 321. By contrast, organic matter in rhizosphere soil at the budding stage, catalase activity at the budding stage, urease activity at the seedling and flower and boll stages, and alkaline phosphatase activity at the seedling stage were significantly lower than the check. Cluster analysis showed that the changes of nutrients and enzyme activities in rhizosphere soil were mainly affected by the growth stages, whereas the impact of transgenic Bt＋CpTI cotton planting on the main nutrients and enzyme activities was very limited.