转Bt基因棉花杀虫蛋白含量的时空表达及对棉铃虫的毒杀效果

用ELISA法和室内生测法研究分析了3个转Bt基因棉花株系新棉33B、GK12、GK2不同生育期、不同组织器官的杀虫蛋白表达量、校正死亡率及它们之间的关系.结果表明,杀虫蛋白表达量在棉花生育过程中有明显的时空动态变化.总的趋势是苗期和蕾期杀虫蛋白表达量较高,花期呈下降趋势,花铃期下降最为明显,到铃期和吐絮期含量略有回升.不同组织器官的杀虫蛋白表达量也有显著的差异,其顺序为叶＞铃、花心、花萼、蕾＞花瓣＞苞叶.室内生物测定棉铃虫幼虫校正死亡率与其杀虫蛋白表达量高度一致.转Bt基因棉花应加强中后期对棉铃虫的监测和补充化学防治.

ON THE SPATIO-TEMPORAL EXPRESSION OF THE CONTENTS OF Bt INSECTICIDAL PROTEIN AND THE RESISTANCE OF Bt TRANSGENIC COTTON TO COTTON BOLLWORM

The tendency and the relationship between the content of Bt ( Bacillus thurngiensis Berliner) insecticidal protein( BtIP) in Bt transgenic cotton and the morality of cotton bollworm He-licoverpa armigera (Hubner) were studied by applying ELISA and laboratory bioassay. The results showed that there were obvious spatio-temporal changes of the content of BtIP along the developmental process of Bt transgenic cotton. Generally , the order of BtIP contents according to the growing period was seedling > squaring > flowering > flowering-boll < boll < boll opening; and the order of BtIP contents according to the organs of cotton was leaf > boll, flower heart and scjuare > petal > bract. The tendency of larval moralities in indoor bioassay were consistent with that of BtIP contents in different growing periods/organs , i. e. high morality occurred in the growing period /organ possessed high BtIP content. It was indicated that owing to the decrease of BtIP content in middle or late period of Bt transgenic cotton, to strengthen the population monitoring and adopt complementary chemical control against 3rd and 4th generation cotton bollworm are necessary.