Studies On Relations Between The Compositions Of HMW-GS Of Wheat Core Germplasms And Bread-baking Quality

The high molecular weight (HMW) glutenin subunit compositions of 240 wheat germplasm materials, which have been filtrated and identified for many years by breeding specialists of HeBei Agricultural University, were determined after grain proteins were fractionated by polyacrylamide gel electropheresis in the presence of sodium dodecyl sulphate (SDS-PAGE), and their relationship to bread-making quality was studied. In addition, the relations between the wheat protein compositions and HMW-GS compositions were studied by using 38 wheat germplasm materials.The results indicated that (1) The germplasm varieties collected from various areas have different HMW-GS compositions. For frequency of good quality subunits 1, 5+10 and 7+8, foreign varieties were higher than Chinese varieties. HMW-GS compositions of Chinese germplasm materials have been improved. But at the same time, the frequency of some high quality subunits such as 2* and 5+10 have been obviously decreased.(2) The allelic variation band 7*, which were not been reported before, appeared in the shape of combinations of subunits 7*+8 or 7*+9. All tested qualities of subunits 7*+9 were obviously better than subunits 7*+8. For the falling number, GMP content and the proportion of GMP in the whole protein, subunits 7*+8 and 7*+9 were both significantly better than subunits 7+8 and 7+9. The qualities of another variation of 1Dx were not so well that it had no great applying value.(3) The correlation analysis showed that subunits on Glu-1 loci mainly affected GMP content and the proportion of GMP in the whole protein. Subunits 7 (positive correlation), 6+8 (negative correlation) and 5+10 (positive correlation) had significant effect on starch qualities. Subunits 5+10 were not only extremely significantly andpositively correlated to GMP content and the proportion of GMP in the whole protein, but also significantly and positively correlated to swelling power.(4) Different types of subunits had different qualities under the same genetic background. It more accurately illustrated the effects of every subunit on bread-making qualities of wheat.(5), Two-factor analysis of variance showed that the effect on swelling power was mainly additive effect of Glu-B| locus, coupled with interactive effect among Glu-Ailocus and Glu-D, locus. The effect on amylose content was mainly additive effect of Glu-D, locus. The additive effect of Glu-Bi locus was the same important as the interactive effect among Glu-B, locus and Glu-D1 locus on falling number. The effects of Glu-1 locus on GMP content were mainly additive effect of Glu-A1 locus.(6) Different HMW-GS compositions resulted in different protein components content to a certain extent. And it showed a certein regular pattern.