Abstract: 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.

Key words: CpTI-Bt transgenic cotton, Bt transgenic cotton; Helicoverpa armigera; survival, growth, nutrition utilization