Effect Of Protein Content Selection On Quality And Yield Traits And Genetic Diversity In Hybrid Progenies

Cooking and eating quality was an important quality character in rice, and protein content affected Cooking and eating quality primary. The protein content has the close relation with other quality character and the agronomic characters, and protein content's changed would cause other character changed inevitably. So the research about protein content choice had the important theory and the practice guiding sense to the hybrid's quality and yield and the heredity multiple also influenced to the good quality and high yield.In this experiment two crosses-Xixuan 1×Tong 769, Dongnong 423×Fukei 180 -were made using four Japonica rice parents with difference in quality and yield, and genetic variability and selection efficiency of protein content were studied in hybrid progenies from F₅ to F₇ generation. The results showed that:Selection for protein content in progenies was effective. Selection with different content in generation would gain generation which had significantly higher or lower protein content than parents. And it was found that selection effect for high protein content was better than for low protein. Selection effects changed when the parents were different.The protein content and the amylose content assumes the inverse correlation, and both has a marginal value. When the amylose content was 15%²0%, the protein content played more important part than the amylose content in cooking and eating quality. And high protein content cause production to decrease. The protein content in the parental generation is near to each other, however, hybrid progenies with different content of protein in grain and higher or lower activities of Proteinase and Glutamine synthetase may be acquired by use of consecutively directed selection of the grain protein content in their hybrid progenies. And the enzyme activity and content of protein in grain will excel their parents during the course of their grain filling. The content of protein in rice and the activities of Proteinase and Glutamine synthetase was positively related and the content of soluble protein in grain and activity of Glutamine synthetase were negatively related to some extent, and Cluster analysis of parents and progencies indicated that high protein hybrid progencies could cluster together, low protein hybrid progencies could cluster together. Successive selecting for protein content of hybrid progenies, genetic background of its progenies did deviate to one of their parents, which was unfavorable to excellent gene of polymeric parents and genetic diversity of progenies...