新疆南部棉区转Bt基因棉花对棉铃虫抗性的季节性变化规律

The seasonal dynamics of resistance of transgenic Bt cotton to cotton bollworm in cotton planting region of southern Xinjiang

采用ELISA检测和室内生物测定方法,测定6个转Bt基因棉花品种(系)不同生育期叶片中的Bt毒蛋白含量及其对各世代棉铃虫的抗性水平。转Bt基因棉花叶片中的Bt毒蛋白含量总体上随着棉花生育期的推进而逐渐下降,6个品种(系)叶片的Bt毒蛋白含量子叶期最高,达1 210.03～1 733.15 ng/g,与子叶期相比,三叶期、七叶期、盛蕾期、花铃期、吐絮期Bt毒蛋白含量减少幅度为2.5%～96.0%。6个品种(系)对第4代棉铃虫幼虫抗虫性较低,毒杀效果仅为19.0%～41.3%。幼虫的校正死亡率逐代下降,各棉花品种对第4代幼虫的校正死亡率仅为12.0%～36.2%。

The levels of Bt toxic protein in six kinds of transgenic Bt cottons in different periods were detected using ELISA and the levels of the resistance of those cottons against cotton bollworm larvae of local four generations were tested using laboratory bioassay. The levels of Bt toxic protein in tender leaves of transgenic Bt cotton decreased gradually with the cotton growing up. The level of Bt toxic protein was highest in cotyledon period, reaching 1 210.03 - 1 733.15 ng/g. Compared with the cotyledon period, the reduced ranges of the Bt toxic protein in tender leaves of three-leaf period, seven-leaf period, squaring period, flowering and little boll period, boll opening period were 2.5% -96.0%. The resistance of those cottons to 4th generation larvae was lower, and only up to 19.0% -41.3%. The corrected mortali- ty of the 4th generation larvae were merely only 12.0% - 36.2% , lower resistance were indicated.