Study On Biochemical And Genetic Basis Of Quality Breeding In Common Wheat (Triticum Aestivum L.) In Southwest China

To improve wheat quality is one of the main goals of wheat breeding in China. Many reports showed that the vital factors, affecting the making-bread quality, were protein quality and protein content and that despite the key factors that affected the processing quality of noodle were distinct in different kinds noodle, protein and starch traits were the limit factor of noodle quality. In view of the problem of wheat quality in the North of China, many researchers have done much work and made some achievement, but the wheat quality of the southwest region was so bad against that of the north region that it could not meet the need of food processing. At present, most of the wheat cultivars in southwest wheat region are not fit to process good bread, noodle and steamed bread, and the economic benefit is low, which influence the positivist of fanners to grow. There was no system study about the quality problem of wheat cultivars, planted widely in the southwest region of China to date. As far as the problem was concerned, all local cultivars and cultivars cultured in Sichuan Province, cultivars introduced from foreign and cultivars cultured in the north of China were employed in this study in order to discuss the gene source to improve wheat quality in the southwest of China, which systemically studied the composing of HMW-GS; the wheat-rye 1BL/1RS translocation created by chromosome engineering with mono-some addition line method, was applied in the study, with the goal to discover the effect produce by the 1BL/1RS translocation line; the special biochemistry problem in wheat breeding in the southwest winter of China was studied with the cultivars cultured in the recent years, and it was first time to report the limit factors and strategies in bread wheat breeding in the southwest of China; employing the new wheat lines cultured by our research group, the study discovered the biochemistry mechanism of pre-harvest sprouting; the relationship between wheat quality of different cultivars in the southwest wheat region and cooked quality of wet noodle and the relationship between PPO activity. The multi-marker assistant choice system of good quality breeding in the southwest region has been found in this study. The main results were shown as following:The SDS-PAGE analysis results of different origin and different years 160 cultivars showed that there were 14 subunits separated from the Glu-1 locus, allelic variant and subunits combination were different among different origin and different years cultivars. Further analysis discovered that good quality subunits 2*, 17+18 and 5+10, having everything to do with the bread quality, distributed widely among the CIMMTYTcultivars; and that 5+10 subunit was very common among the northern cultivars of China besides the 14+15 subunits which positively influenced the bread-making quality. However, the frequency that 5+10 subunit emerged sequence among different cultivars from high to low were CIMMYT cultivars to new wheat lines in Sichuan province to northern new lines of China to cultivars planted in Sichuan province to local cultivars in Sichuan province. In southwestern wheat region cultivars the Glu-1 gene was simplex, which only existed one composition N, 7+8 and 2+12.However, in cultivars planted, the diversity of Glu-1 gene was improved, but the frequency of good quality glutenin subunits was still lower. Among new lines or cultivars cultured in the recent years, the gene frequency of Glu-1 gene was improved, and the 5+10 subunit was up to 47.62 percent and the quality score reviewed according Glu-1 locus was 7.21, which indicated that it was possible to improve wheat quality through introducing HMW-GS. Hence, it was necessary to breed and used 5+10 subunit, to apply the good quality subunit 1, 2*, 17+18 and 14+15, and to dispose or combine rationally those subunit on the Glu-Al, Glu-Bl and Glu-Dl locus.The study first breed a 1BL/1RS translocation (843-2-1) that it Sec-1 locus had not expression in wheat. Which was rare to study further the mechanism that the expressio...