Different Hmw-gs Type High Molecular Weight Of Spring Wheat Gluten Formation And Accumulation Of The Relationship With Quality

Relationships Between the Quality and the Formationand Accumulation of Grain HMW Glutenin in genotypes with Different Glu-1 loci in Spring WheatGraduate Student: Sun Xia Supervisor: Li Wenxiong, Prof.(Dept. of Agronomy, Agric. College, NE Agric. University. Harbin 150030)AbstractThe nutritional and processing quality in wheat grain was determined by the protein content, fractions and the ratio, as well as the composition of subunit. Although the studies were often on the protein content, fractions, subunit, HMW-GS and quality, reports on the dynamic accumulation of grain HMW glutenin, the factor affecting it and relationship with quality are rarely found. The nitrogen plays an important role in plant growth and development and protein producing. The time of nitrogen fertilizer application and the kinds of nitrogen fertilizer directly affected the grain protein content and quality in wheatThe studies were carried out in Harbin from 1999-2000 by using the genotypes differing in HMW-GS. The studies aimed at the formation and accumulation patterns of glutenin and HMW glutenin, as well as relating with quality. The dynamic accumulation of glutenin and relating to quality during the formation of seeds was also studied to provide the theoretical basis in quality improvement.The results showed that the glutenin initiated around 10-15* days post anthesis differing with genotypes, and the LMW glutenin initiated firstly, then HWM, in glutenin formation. Along with the grain filling, the HMW glutenin content increased gradually and attained the maximum at 25* day post anthesis, but the maximum and total accumulation intensity were not the same in different HMW-GS genotypes. During grain filling, HMW glutenin with lower molecular weight initiated firstly, then the higher. NKH9, Q224 and S57 with the subunits 7+9 and 2+12 attainted the maximum of HMW glutenin 20 days post anthesis, and the others 25 days. The total accumulation amount of HMW glutenin was not the same in the cultivars with different HMW-GS. As to the dynamic accumulation and totalaccumulation amount of HMW glutenin. the effects of the kinds of nitrogen fertilizer were controlled by the cultivars heredity and not related to the different HMW-GS composition. Cluster analysis showed that the kinds of nitrogen fertilizer affected the accumulation of HMW glutenin. The cultivars with good quality had the high HMW glutenin accumulation. The cultivars with the subunit 7+9 and 2+12 fell into the same group, but the cultivars with the subunit 7+8 or 5+10 were complicated. The variance analysis showed that the total accumulation amount of HMW glutenin were positive correlation with quality, but not significant.No significant effect of the different kinds of nitrogen fertilizer on protein content, gluten index and falling number was found in the studies. Significant correlation in nitrogen treatments was found in the studies. It meant that the SDS-sedimentation value was controlled markedly by the different kinds of nitrogen fertilizer. There were significant positive correlation between the protein content, dry gluten and wet gluten, but they were negative with falling number and SDS-sedimentation value. The correlation between gluten index and protein content was negative, but significant positive with dry gluten, wet gluten, falling number and SDS-sedimentation value. As to falling number and SDS-sedimentation value, the correlation was positive significantly. Therefore, quality could be evaluated correctly when combining the gluten content, gluten index and SDS- sedimentation value in use.