Effects Of Environment On Wheat Quality And Combining Ability, Heterosis Research In Wheat

The variation of quality parameters in high quality cultivar Zhengmai366 and 15 wheat varieties were studied, the effects of different environment and genotype on quality parameters were discussed. Some quality parameters and factors which are important to bread baking quality and dough rheological parameters were determined, which provided a theory basis for early generation selection in high quality wheat breeding. By using NCâ…¡diallel cross F1 at two sites, the combining ability and heterosis of yield and some quality parameters were determined.The main results obtained in this study are presented as below:1. The environmental effect on wheat quality mainly shows in the change of protein quanlity. The variation coefficient of the early generation selection parameters,water absorption rate and bread baking quality were less than 10%; and the variation coefficient of development time, stability, softening, L value, W value were greater than 10%. So by choosing appropriate site, improving the cultivation techniques or strengthen cultivation management can raise the protein content and then improve the wheat quality.2. The loaf volume were significantly and positively correlated with GMP content, flour protein content, kernel protein content, gluten index content,gluten index value,sedimentation value,development time and W valu(ep<0.01). It shows the loaf volume is not only affected by protein quantity but also by the protein quality. So enhancing the bread baking quality should not only pay attention to raise the protein content but also by improving the subunit composition of protein in wheat varieties.3. Protein content, GMP content and sedimentation value, just used a small amount of sample, are closely related to bread baking quality and can be used for the early generation selection. Much attention should be paid to the degree of softening in Farinograph, and the W value is the most important parameter in Alveograph for bread baking.4. Parents performance and quality parameters shows more consistent in general combining ability, so general combining ability should be accounted for a major position in quality parameters. The average heterosis of loaf volume and loaf score were 1.55% and 1.87% in Yuanyang, the rate is higher and most combination were positive advantage; the average heterosis of loaf volume and loaf score were 2.43% and 5.64% in Jiaozuo,it's better than Yuanyang. These show the heterosis in bread baking quality is obviously, and can be used in hybrid breeding. The general combining ability is an important parameters to heterosis.5. General combining ability and special combining ability is different in two locations, so the experiment should be done more than one year and one site to give local determination for breeding .6. Using high quality parents to improve the poorer quality parents are effective.In high molecular weight glutein, the parents which contain 5+10 hushais is better, and protein content should be paid more attention when the high quality parents choosed. Furthermore, the yield of high quality is unfavorable too low, so it can be selected both high yield and quality varieties. Parents selection should be paid attention to complementary the yield and quality characters when they are combined.