Study On The Variance And The Indicators Of Grain Quality

The experiments studied grain physics-chemical characters and flour baking quality at three sites in iiangsu province in 1998?000. Forty wheat varieties grown in East-china were used to investigate the effects of genotype, environment and their interaction ,access evaluation indicators of grain quality , analyzed the dynamic of dry matter and nitrogen in grain related to genotype and environments. The results showed: High significant differences were detected among genotype MS for all the quality characters. Starch content, linear starch content and gluten index were insensitive to environment. Significant variance in protein content, gluten content, sedimentation value and test weight et al were found under different environments. The effect of GXE was significant on all quality parameters. The responses of quality and yield among varieties to environment were different. Significant correlation between most grain quality traits were found, specially between protein content, gluten content and sedimentation value which were positively correlated with starch content. Starch content was significant positively correlated with ash content, flour yield and falling number. Test weight was significant negatively correlated with 1000-kernal weight while positively correlated with sedimentation value, gluten content, gliadin content and the total of them. Least negative correlation between yield and quality suggested that simultaneous improvement for them may be easy. Correlation and principle analysis showed that protein content, gluten content, flour yield, starch content and test weight were important factors determining grain quality. Linear regressionship between bread volume and score, protein content, dry gluten content and wet gluten content was found. Gluten content is more important than protein content to bread volume and score. Protein content, sedimentation value, falling number 1000-kernal weight and ash content determined biscuit score for 58.2% while protein content and sedimentation value were negative to biscuit score. 63 The effects of genotype and environment on grain protein components were significant while little effect ofGXE on globulin content. The ratio of gluten/glidin in Xuzhou was bigger than that in Nanjing. In high protein grains, Quadratic relationship between bread specific volume and the ratio of gluten/gliadin was found and 1.3 as the ideal ratio of gluten/gliadin. Seventy percent of nitrogen in wheat grain come from the re-allocation of accumulated nitrogen in wheat plant before anthesis while eighty percent of dry matter from photo-assimilation after anthesis. The source and re- allocation of nitrogen and dry matter in grains varied with the change of Igenotypes and environments.