施氮方式对转基因棉花Bt蛋白含量及产量的影响

为研究氮肥运筹对棉花叶片、棉蕾和棉铃不同器官中Bt蛋白含量的影响，2009—2010年，以抗虫杂交棉中棉所72为试验材料，在大田条件下进行了不同基肥：花铃肥：盖顶肥施氮比例（分别为0:0.4:0.6、0.2:0.4:0.4、0.4:0.4:0.2、0.6:0.4:0）的试验。结果表明，施氮方式对棉花不同器官中Bt蛋白含量有明显影响。总体表现为随着氮肥前移，棉花幼嫩器官中Bt蛋白含量呈明显增加的趋势，而老熟器官中Bt蛋白含量呈明显降低的趋势。施氮方式对棉花幼嫩器官中Bt蛋白含量的影响比老熟器官明显，尤其是对幼嫩叶片Bt蛋白含量的影响大于幼小的棉蕾和棉铃器官。抗虫棉采用基肥：花铃肥：盖顶肥为0.4:0.4:0.2的施氮方式，总体能提高前中期棉花器官Bt蛋白的含量，有利于提高其抗虫性能；减少后期棉花器官Bt蛋白的含量，减轻对环境的压力；而且比其余3种施氮方式的籽棉产量和皮棉产量分别增加4.15%—11.24％、3.73%—12.01%。

Effects of nitrogen fertilizer methods on the content of Bacillus thuringiensis insecticidal protein and yield of transgenic cotton

Nitrogen application strategies may be one of the main methods to regulate Bacillus thuringiensis (Bt) insecticidal protein metabolism of cotton (Gossypium hirsutum L.). To investigate the effects of nitrogen fertilizer methods (NFM) on the content of Bt insecticidal protein (CBIP)in leaf,bud, hull of boll, fiber and seed, we conducted field experiments for transgenic cotton,on a sandy loam at the Experimental Farm of Henan Agricultural University during 2009-2010.The soil contained about 9.26 g/kg organic matter, 1.03 g/kg total nitrogen, 18.36 mg/kg available phosphorous and 96.56mg/kg available potassium, respectively.The ratios of the application of nitrogen fertilizer before sowing, in flowering stage and peaking bolls setting stage were 0.0:0.4:0.6, 0.2:0.4:0.4, 0.4:0.4:0.2 and 0.6:0.4:0.0, respectively. The amount of nitrogen fertilizer was 300kg/hm²of pure N. The experiment was carried out with a completely randomized design with three replications. The CBIP in transgenic hybrid cotton CCRI (China Cotton Research Institute)72 was quantified using Enzyme-linked Immunosorbent Assay(ELISA).The results showed that the CBIP in young cotton organs tended to be the order of fiber > leaf > hull of boll, bud > seed, but in overripe cotton organs tended to be the order of seed > leaf > hull of boll > fiber, especially CBIP in seed were 48.5-68.4 times higher than that in fiber of cotton. NFM had strong effects on CBIP in transgenic cotton.With the advanced nitrogen fertilization, the CBIP in young cotton organs were obviously enhanced, while overripe cotton organs tended to be decreased in general. The results also indicated that NFM has stronger effect on CBIP in young cotton organs than that in overripe organs, especially the CBIP in young leaf was more susceptible than that in young bud and boll. Under the experimental condition of this study, we concluded that the ratio(0.4:0.4:0.2) of nitrogen fertilizer application before sowing, in flowering stage and peaking bolls setting stage of cotton is proper. It may not only increased CBIP in cotton organs in the early-middle period and improved the resistance of Bt insecticidal protein in transgenic cotton to Helicoverpa armigera, but also decreased CBIP in cotton organs in later period and alleviated the pressure of Bt insecticidal protein to environment. Moreover, the ratio (0.4:0.4:0.2) of nitrogen fertilizer application could increase seed cotton yield and lint yield by 4.15%-11.24%, 3.73%-12.01% than three rest treatments, respectively.