Wan Peng, Zhang Yongjun, Wu Kongming, Huang Minsong
Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100094, China.
J Econ Entomol. 2005 Feb;98(1):195-201. doi: 10.1093/jee/98.1.195.
Seasonal levels of Bacillus thuringiensis (Bt) insecticidal protein and its control efficacy against Helicoverpa armigera (Hübner) in Bt transgenic cotton GK19 (carrying a Cry1Ac/Cry1Ab fused gene) and BG1560 (carrying a Cry1Ac gene) were investigated in Tianmen County, Hubei Province, located in the Yangtze River valley of China, in 2001 and 2002. The results showed that the toxin content in Bt cotton changed significantly over time, and that the structure, growth stage, and variety were significant sources of variability. Generally, insecticidal protein levels were high during the early stages of cotton growth; they declined in mid-season, and rebounded in late season. On most dates sampled, the toxin contents in leaf, square, petal, and stamens (including nonovule pistil tissue) were much higher than those in ovule and boll. Compared with BG1560, the expression of Cry1Ac/Cry1Ab protein in GK19 was more variable during the whole growth period of cotton. The field evaluation on larval population dynamics of H. armigera in Bt and conventional cotton showed that the larval densities in BG1560 and GK19 fields decreased, respectively, 92.04 and 81.85% in 2001, and 96.84 and 91.80% in 2002.
2001年和2002年，在中国长江流域的湖北省天门市，对转Bt基因棉花GK19（携带Cry1Ac/Cry1Ab融合基因）和BG1560（携带Cry1Ac基因）中苏云金芽孢杆菌（Bt）杀虫蛋白的季节性水平及其对棉铃虫的防治效果进行了研究。结果表明，Bt棉花中的毒素含量随时间显著变化，其结构、生长阶段和品种是变异的重要来源。一般来说，棉花生长早期杀虫蛋白水平较高；中期下降，后期反弹。在大多数采样日期，叶片、棉蕾、花瓣和雄蕊（包括非胚珠雌蕊组织）中的毒素含量远高于胚珠和棉铃中的毒素含量。与BG1560相比，GK19中Cry1Ac/Cry1Ab蛋白在棉花整个生长期间的表达变化更大。对Bt棉花和常规棉花中棉铃虫幼虫种群动态的田间评估表明，2001年BG1560和GK19田中的幼虫密度分别下降了92.04%和81.85%，2002年分别下降了96.84%和91.80%。
