转CpTI-Bt基因棉和转Bt基因棉对棉铃虫幼虫存活、生长及营养利用的影响

2000年7月中旬和8月中旬, 分别测定了采自田间的转CpTI-Bt基因双价抗虫棉（SGK321, 以下简称CpTI-Bt棉）和转Bt基因抗虫棉（中30，以下简称Bt棉）对棉铃虫Helicoverpa armigera幼虫存活、生长的影响。结果表明：7月中旬两种转基因抗虫棉抗虫效果均较好，尤其是CpTI-Bt棉棉叶和花瓣对4龄幼虫3天内致死率为92%以上；8月中旬两种转基因棉的抗虫活性均明显降低，且Bt棉的杀虫活性显著低于CpTI-Bt棉，其幼虫死亡率与对照受体棉中16的死亡率之间无显著差异，仅显著抑制了幼虫的生长；石远321(SGK321受体品系)的花瓣具有一定的抗虫活性，可显著降低取食幼虫的体重，甚至造成部分幼虫死亡； CpTI-Bt棉中，花瓣和棉叶的抗虫性明显高于蕾和铃心。对5龄幼虫取食棉铃1日后的营养指标测定结果显示： 两种转基因抗虫棉处理的幼虫相对生长率和相对取食量均显著低于石远321，但两者之间无显著差异； CpTI-Bt棉处理的幼虫近似消化率显著低于石远321和Bt棉，但其食物利用率显著高于石远321和Bt棉。

Effects of CpTI-Bt transgenic cotton and Bt transgenic cotton on survival,growth and nutrition utilization of Helicoverpa armigera (Hübner)

Effects of CpTI-Bt transgenic cotton （SGK321） and Bt transgenic cotton （Zhong 30） from the field on the survival and growth of Helicoverpa armigera （Hübner） were tested respectively in mid July and mid August of 2000. The results indicated that both transgenic cottons showed high insect resistance in mid July, especially the leaf and petal tissues of CpTI-Bt transgenic cotton, which led to more than 92% mortality of fourth instar larvae in 3 days. In mid August, the insect resistance of both CpTI-Bt transgenic cotton and Bt transgenic cotton declined，while CpTI-Bt transgenic cotton showed significantly higher insect resistance than Bt transgenic cotton. Compared with Zhong 16 (the recipient cotton line of Bt transgenic cottton), Bt transgenic cotton did not show significantly higher larval mortality, but showed significant inhibition of larval growth. Petal of Shiyuan 321 (the recipient cotton line of CpTI-Bt transgenic cotton) showed some inse ct resistant activity, which led to the inhibition of larval growth and even death of some larvae. In SGK321 with expression of CpTI and Bt insecticidal protein genes, both petal and leaf showed significantly higher insect resistant activity than bud and boll heart. Nutrition index of 5th instar larvae on consumption of boll indicated that while either RGR or RCR in larvae treated with CpTI-Bt transgenic cotton or Bt transgenic cotton showed no significant difference between the two treatments, both were significantly lower than that in larvae treated with Shiyuan 321, the recipient cotton line of SGK321 Larvae treated with CpTI-Bt transgenic cotton showed significantly lower AD and higher ECI than those treated with Bt transgenic cotton and Shiyuan 321.