Effects Of High Molecular Weight Glutenin Subunits Expression Contents On Wheat Processing Quality

The kinetic accumulations of HMW-GS expression amounts during grains development were studied by using 6 cultivars having different quality. 8 winter wheat cultivars were used to carry out different locations experiments. In order to elucidate the effects of environments on HMW-GS expression, 2 cultivars were used to carry out the experiment of temperature treatments, and nitrogen fertilization was conducted for the PH3259 cultivar. Furthermore, the experiment on HMW-GS contents was implemented using near isogenic lines of wheat. HMW-GS expression contents and their effects on flour quality, dough quality, breadmaking quality, steamed bread quality and noodle quality under different conditions were researched in order to provide some theory gists about wheat quality breeding and wheat having good quality planting. The main results were as follows: 1. Extraction methods and quantitative research of HMW-GS contents The best method for extraction of HMW-GS contents based on others'research is that monomeric proteins were removed by the solution containing 0.3MNaI and 7.5% Iso-propanol, then HMW-GS and LMW-GS were extracted by the solution having 50% iso-propanol, 0.08MTris-cl(Ph8.8) and 1% DTT. In order to prevent the formation of S-S bonds again, the solution containing 1.4% 4-VP was used to alkylate the sulfhydryl. Through SDS-PAGE, the gel was analyzed by the program of 1D-Multi system of ChemiImagerTMIS-4400 type imaging densitometry (32 KaratTM software ver.5.0 P/ACE MDQ, BECKMAN COULTER Corpration, Germany) using Quantity One software. HMW-GS comparative contents/GMP indicated the content of HMW-GS. 2. HMW-GS kinetic accumulations and their effects on processing quality using winter wheat cultivars having different quality During the development of grains among six cultivars having different quality, their initial formation time and accumulation rate were different. B groups of LMW-GS were formed at ten days after anthesis. HMW-GS types of strong gluten wheat such as PH3259 and Gao8901 were completely formed at ten days after anthesis, while X-type HMW-GS of 101 and YM3 were only formed at that time. With the development of grains, the types and accumulation amount of HMW-GS and LMW-GS became more and more. Comparative to weak gluten wheat, GMP accumulation of strong gluten increased sharply and individual HMW-GS accumulation rate became more rapid from 25 days after anthesis to grains maturation. The same HMW-GS accumulation trend was similar among different wheats, but their accumulation amount was different: stong gluten wheat superior to weak gluten wheat. Wheat quality was affected by HMW-GS formation time and accumulation amount. The kinetics accumulation amount of HMW-GS positively correlated with major parameters of dough rheological properties, and extremely significantly correlated with the stability time of farinogram. There was significant correlation between HMW-GS amount at maturation and dough rheological parameters, score of Glu-1 and SDS-sedimentation volume. Bread volume and bread evaluation score individually significantly and extremely significantly correlated with HMW-GS expression amount, while HMW-GS amount negatively correlated with bread firmness. Therefore, besides the types of HMW-GS, their formation time, accumulation intensity and expression amount at maturation all affected the wheat bread making quality. 3. Effects of environment and genotype on wheat HMW-GS expression amount and bread making quality and streamed bread quality 3.1 Effects of environment and genotype on HMW-GS expression amount and its relationship with bread making quality and streamed bread quality Although some subunits were affected by environments, genotypes played an important role for X-type HMW-GS, Y-type HMW-GS, Glu-1D location and Glu-1B location. Total HMW-GS amount was affected by the interaction between genotype and environment. Individual HMW-GS content of the same genotype was affected by environment in the different degree. Yantai location was superior to others'location for many HMW-GS expression amounts. The same kind of HMW-GS from different genotypes appeared differentin the same environments. Glu-1A1, Glu-1B7+8 and Glu-1B13+16 all amounts were affected by a bigger degree than Glu-1D5+10 by environments. Individual HMW-GS amount had applicable environment for best expression. It appeared HMW-GS expression amount positively correlated with bread volume, and negatively with bread peak firmness. Effects of individual and total HMW-GS on steamed bread quality were different from bread quality. Glu-1A1, Glu-1B7+8 and Glu-1D2 had contributed to steamed bread volume and score. Effects of total HMW-GS on bread volume were better than individual HMW-GS. HMW-GS types, first determined bread quality then HMW-GS expression amount, while steamed bread quality was mainly affected by HMW-GS amount. 3.2 Effects of environment and genotype on dough quality, bread-baking and steamed bread quality Dough rheological properties were affected by genotypes, environments and their interactions, genotype variation means>environment variation means>G×E variation means. Characteristics of Jimai 20 appeared best among genotypes, and Yantai location appeared best characterisitcs among environments. Genotypes significantly affected GMP, HMW-GS and LMW-GS. Sedimentation volume, mid peak time and 8-time width were affected smaller by environments than by genotypes. Genotypes, environments and interation between them all significantly influenced the bread volume. Genotypes determined the peak firmness of steamed bread quality or bread quality. Effects of bread volume showed bigger degree than steamed bread volume. There appeared not significant for effects of environments on many steamed bread quality parameters. Correlation analysis indicated that dough stickness appeared negative correlation with maximum extensibility resistance, R/E ratio, peak time, peak area and 8 time width, while positive significant with extensibility. Maximum extensibility resistance was positively significantly correlated with peak time, peak area and 8-time width. 4. Effects of temperature treatments on wheat HMW-GS amount and noodles quality HMW-GS expression amounts from different gluten strength had different reactions for temperature treatments. HMW-GS amounts of high gluten strength had stronger endurance for temperature, but HMW-GS amounts of wheat with low gluten strength were easily...