Effect Of Potassium Rates On Physiological Mechanism Of Cottonseed Yield And Cottonseed Quality In Transgenic Cotton

cottonseed quality is mainly affected by the combined effect of the quality of The formation of cottonseed quality is related to the cooperation of genetic, environmental and ecological factors and cultivation measures. K(Potassium) is one of the regulating factors to the production and quality of cotton. For improving yield and cottonseed quality through K, the physiology basis of potassium regulating the difference of formation between different genotypes of cotton was studied in this research. In 2012～2013, field experiments were carried out in Nanjing (118°50’E,32°02’N, middle lower reaches of Yangtze River Valley). Two cotton cultivars with different genetic cotton (Simian 3 and Siza 3) were chosen, and three potassium rates (0 kgK·ha-1,150 kgK·ha-1,300 kgK·ha-1), Potassium was applied as basal 50% and the blooming period 50%.The study focused on:(1) Effect of K rates on the development of cottonseed, cottonseed biomass and cottonseed yield; (2) Effect of K rates on carbon metabolism related with enzymes and substance of cottonseed; (3) Effect of K rates on fat and protein Contents in cottonseed kernel. The main results were as follows:1 Effect of K rates on development and yield in cottonseedCottonseed volume approximate "S" shaped curve. After fitting with Logistic growth model equations have reached a significant level. Therefore, the formation of cottonseed volume can be fitted with Logistic growth model. Potassium can promote cottonseed volume slowly increases, improved theoretical maximum. Cottonseed biomass similar to "S" shaped curve with days post anthesis. Cotton shell biomass accumulation ahead of cottonseed biomass accumulation. Compared with potassium treatment, potassium deficiency leads to material outward hindered on cottonseed hulls. Potassium can be increased to improve kernel and hull ratio, seed index, less affected for grains per poll, so, potassium can increase cottonseed boll weight. K fertilizer can also improve the bolls and cottonseed yield. Cottonseed production amount of potassium in 300 kg·ha-1 treatment harvest high than cottonseed production harvested 150 300 kg·ha-1 treatment, and reached a significant level, Under conditions of low potassium, Siza-3 in seed index, boll number and cottonseed yield more sensitive than Simian-3. Therefor, etransgenic cotton is more sensitive than traditional cotton response to low potassium2 Effect of K rates on carbon metabolism related with enzymes and substance of cottonseedThe main carbon metabolism substances include soluble sugars, starch and sucrose in cotton kernels. Soluble sugar and sucrose similar trend, soluble sugar and sucrose content continues to decline from 17 to 31 days after flowering, then soluble sugar and sucrose content has a small rise. Potassium can improve the soluble sugar and sucrose conversion, but not conducive to the conversion of starch, and siza-3 in soluble sugar and sucrose conversion more sensitive than simian-3. Sucrose is the main form of transport carbohydrates in plants, and is closely related to sucrose metabolism enzymes are mainly sucrose phosphate synthase (SPS), sucrose synthase (SuSy) and invertase (Inv). Potassium significantly increased the SPS, SuSy and Inv activity, but SuSy activity inconsistent in two years. Early stage of cottonseed development, while until 31DPA, Inv activity was significantly higher the SPS and SuSy activity, which is consistent period of rapid conversion of sucrose. Siza-3 SPS, SuSy and Inv enzyme average activity on coefficient of variation greater than and Simian 3 in kernel, shows that Siza-3 cotton in SPS, SuSy and Inv activity more vulnerable to the impact of potassium deficiency.3 Effect of K rates on fat and protein Contents in cottonseed kernelPotassium reduces the amino acid content, protein content and GS/GOGAT activity, the more the amount of potassium decreased more. Cottonseed amino acid content and GS/ GOGAT activity Cottonseed amino acid content and GS/GOGAT activity Cottonseed amino acid content and GS/GOGAT activity was declined with the day post analysis, while the protein content increases with day post analysis of flowers acquired approximate "S" type, Through correlation analysis amino acids, protein, GS and GOGAT activity in cottonseed kernel development found that the protein content with GS and GOGAT activity showed a significant positive correlation. Therefore, cottonseed higher amino acid content, GS and GOGAT activity are conducive to the accumulation of proteins. Potassium can increases the fat content in cottonseed kernel. Cottonseed fat content in 2012 compared to 2013 year high before the boll. This may be affected the high temperature of 2013, while shortening of the cotton boll, resulting kernel fat accumulation time is shortened, on the other hand, inhibition of PPase activity, resulting in reduced accumulation of fat content.