Genetic Analysis Of Multiple Generations For Oil Content In Cottonseeds

Cotton is not only the main source of plant fiber,but also one of the important oil crop in china. It will have great economic and social benefits improving the oil content of cotton seeds. In this study, a series of hybrid combinations from high oil parents and low oil parents were constructed. The main objectives of this study were:(1) dissect the genetic effects of seed oil content in cotton;(2) evaluate the genetic bases of cottonseeds oil content by the joint genetic analysis with six generations;(3) assess the correlations between cottonseeds oil content and agronomic traits. Our results had the great potential to promote the genetic improvement of cotton varieties with high seeds-oil content. The results of research are as follows:1. Through comparison the variance of seed-oil content of two hybrid combinations across six generations, Jing55263and Jimian228, Sulianmian91xi and Yinrui361, we found that the oil content of cottonseeds corresponded the plants which the seeds produced from. Through the analysis of nine crosses, Sulianmian91xi×Yinrui361, KucheT94-4×Wanmian10, Jing173×Jing55263, Jing173×Sulianmian91xi, Jingl73×KucheT94-4, Jing55263×Jimian228, Jimian228×Jing55263, Yinrui361×Sulian9, Wanmian10×KucheT94-4, we found that the cottonseeds oil content were influenced by maternal effects and cytoplasmic effects, but not by the nuclear effects and Xenia effects. Indicating that the seeds oil content were determined by the genotypes of the plants2. Four reciprocal crosse combinations were derived from Jing55263×Jimian228and Yun93kang354×DP410B. Based on the joint genetic analyses of six generations,, the inheritance of oil content were indentified to accord with the model of polygenes with additive-dominance-epistatic effect for all cross combinations. In addition, the combination, Yun93kang354×DP410B, fitted the model featured as one major-gene with additive-dominant effect, and the dominant effect were greater than additive effect.3.By study the F3lines derived from the cross between Yun93kang354and DP410B, Oil content of cotton seeds had exhibited no significant correlations with lint yield, but showed significantly negative correlation with lint percent(-0.39) and fiber elongation(-0.36), and positive correlation with fiber strength of (0.96). Cotton breeding for high oil content would have no impediment in the yield, and the fiber strength could be raised as the improvement of oil content, but coordination of lint percent were needed in high oil cotton breeding.