| To investigate the genetic variation of quality character and mutation breeding of quality improvement in wheat, genetic variation of the main quality traits of315wheat varieties (lines) was studied, the genetic parameters of quality traits were estimated, and the variation and distribution of high molecular weight glutenin subunits(HMW-GS) were analyzed. Genetic variation and distribution of yield and quality character of317M3lines of Chongqing bread wheat radiated by60Coγ-ray.60Co-γ ray were analyzed, mutants were selected, and the HMW-GS mutants were identified. The purpose of this study is to provide reference for selection of quality breeding resource and traits in wheat, and to create new kind of quality germplasm and explore new way of quality improvement. The results are as follows:1. Among the tested315Wheat Cultivars (lines), genetic variation analysis has been done to the protein content, wet gluten content, zeleny sedimentation value, hardness and starch content. Analysis of variance showed that the quality characters of varieties (lines) difference at0.01significant level. Based on the coefficient of genetic variation, the sequence from large to small is hardness, wet gluten content, zeleny sedimentation value, protein content, and starch content. The heritability of5characters above are very high, the broad sense heritability were above95%,5quality traits in selection under the certain strength have certain genetic progress. The hardness had the larger relative genetic progress, the second is Zeleny sedimentation value. The direction of genetic correlation and phenotypic correlation is same. There were significant positive correlation between protein content and wet gluten content, protein content and sedimentation value. There was no significant correlation between protein content with hardness. Protein content negatively correlated with starch content. Wet gluten content positively correlated with and zeleny sedimentation value and hardness, and negatively correlated with starch content. Zeleny sedimentation value was significantly correlated with the hardness. Hardness was significantly correlated with starch content.2. The HMW-GS of200wheat varieties were identified, there are a total of15kinds of mutations, which has three kinds on the Glu-Al site, nine in Glu-B1loci, three in Glu-D1loci. Null and1on Glu-A1,7+8and7+9on Glu-B1, and2+12and5+10on Glu-D1were primarily. There were22kinds of combination in HMW-GS. Null,7+8,2+12was the highest proportion of27.64%. Null,7+9,2+12is lower proportion of16.08%.1,7+9,2+12was11.56%,1,7+8,2+12was8.54%, and1,7+9,5+10was8.04%. The rest of the combination types are not more than8%.3. The variation of plant height, ear traits, yield traits, quality traits of317M3lines was analyzed. The result showed that there were plentiful diversity of plant height, spike number, spike length, spikelet number,1000-grain weight, grain number per spike, grain weight per spike, line yield, protein content and wet gluten content in M3generation.38positive and6negative mutant lines for10characters above were identified depending on the selection criterion of over mean±2.58SD (P(|u|≥2.58σ)≤0.01). Line48, line58, line71, line307and line311had better comprehensive character, which were much more than Chongqing bread wheat in line yield, protein content and wet gluten content.4. One mutant line of high molecular weight glutenin subunit of Chongqing bread wheat were identified in M3by SDS-PAGE, which is named line292, the difference of HMW-GS composition and parent bread wheat in Chongqing has3subunits. |
