Studies On Relationships Between Boll Development And Bt Protein Expression And Regulation Of Growth Substances In Bt Cotton

The study was undertaken on five boll worm resistant transgenic cotton cultivars, which were kemianNO.3,XiangzamianNO.3,SikangNO.1,SikangNO.3,SizaNO.3,during the 2005 and 2006 growing seasons at the Jiangsu Provincial Key Laboratory of Crops Genetics and physiology, Yangzhou University, Yangzhou, China. The object of this study was to investigate the relationship of boll development and Bt protein expression and the adjustment effect of plant growth substances on the boll development and high yield expression cooperate with Bt protein. The main results were as follows:1. The boll volume,the boll shell volume,the boll shell weight,the boll weight and 100-seeds weight of big boll cultivars KemianNO.3,normal boll cultivars XiangzamianNO.3 and small boll cultivars SikangNO.1 were increased during growth stage. The boll volume,the boll shell volume and the boll shell weight of three cultivars both increased greater at 20 days after anthesis, and the boll weight and 100-seeds weight increased greater at 20³0 days after anthesis. At 20 days after anthesis, the boll shell Bt protein expression was negative correlation significantly with the boll volume,the boll shell volume and the boll shell weight ,the cottonseed Bt protein expression was negative correlation significantly with the boll weight and 100-seeds weight.the boll shell and Bt cottonseed protein expression of three cultivars both decreased at10²0 days after anthesis, increased 20³0 days after anthesis, then decreased 30⁵0 days after anthesis. The degradation trend of the content of total nitrogen, amino acid, soluble protein, activities of GPT was also similar. The Bt protein expression was positive correlation significantly with total nitrogen, amino acid, soluble protein, activities of GPT.2.Four cultivars(kemianNO.3,SikangNO.1,SikangNO.3,SizaNO.3)was treated with leaf-cutting and square-removing. Compared to the control, the boll volume, the boll shell volume, the boll shell weight, the boll weight and the weight of 100-seeds were lighter with leaf-cutting, and were weighter with square-removing. The Bt protein expression was weighter with leaf-cutting, and was lighter with square-removing. The degradation trend of Bt protein expression was gradually decreased at 0²1 days after anthesis, then gradually increased. the boll shell Bt protein expression was negative correlation significantly with the boll volume,the boll shell volume and the boll shell weight ,the cottonseed Bt protein expression was negative correlation significantly with the boll weight and 100-seeds weight. Compare to control, the content of total nitrogen, amino acid, soluble protein, activities of GPT, GOT, NR were higher with leaf-cutting, and lower with square-removing. The Bt protein expression was positive correlation significantly with the content of total nitrogen, amino acid, soluble protein, activities of GPT, GOT, NR. The trend of the content of total nitrogen, amino acid, soluble protein, activities of GPT, GOT, NR both were gradually decreased at 0²1 days after anthesis, then gradually increased.3.Four cultivars(kemianNO.3,SikangNO.1,SikangNO.3,SizaNO.3)were treated with Choloromycetin, kanamycin, MET, DPC, 6—BA and GA ,respectively. At 10 days after anthesis, compared to the control, the boll volume, the boll shell volume, the boll shell weight, the boll weight and the weight of 100-seeds were higher with MET, DPC, 6—BA and GA₃ treatment and lower with Choloromycetin, kanamycin treatment. In four cultivars, SikangNO.3 and kemianNO.3 were promoted greater. Compared to the control, the Bt protein expression of GA₃ treatment was lower, other treatment were higher. The content of total nitrogen, amino acid, soluble protein, activities of GPT, GOT, NR of GA₃ treatment was also lower, other treatment were higher. In six treatment, MET promote greatest; In four cultivars, the boll shell of SikangNO.1 and SizaNO.3 were promoted greater, the seed of SikangNO.3 and kemianNO.3 were promoted greater. At 30 days after anthesis, compared to the control, the boll volume, the boll shell volume, the boll shell weight, the boll weight and the weight of 100-seeds were higher with MET, DPC, 6—BA and GA₃ treatment and lower with Choloromycetin, kanamycin treatment. Compared to the control, the Bt protein expression of MET and 6—BA treatment was lower, other treatment were higher. The content of total nitrogen, amino acid, soluble protein, activities of GPT, GOT, NR of MET and 6—BA treatment was also lower, other treatment were higher. In six treatment,GA₃ promote greatest; In four cultivars, the boll shell of SikangNO.1 and SizaNO.3 were promoted greater, the seed of SikangNO.3 and kemianNO.3 were promoted greater.