Allelic Variations Of The HMW Glutenin Subunits In Wild Emmer Wheat (Triticum Dicoccoides T.)

Wheat seed storage proteins,especially glutenin,are important for processing-quality of wheat flour.The glutenins are the major components of wheat storage proteins,which consist of high-molecular-weight glutenin subunits(HMW-GS) and low-molecular-weight glutenin subunits(LMW-GS).It is well known that the composition and content of HMW and LMW glutenin subunits could influence the flour processing and bread-making quality.Genetic diversity of high molecular weight glutenin subunits(HMW-GS) encoded by the Glu-A1 and Glu-B1 loci were investigated by using one-dimensional sodium dodecylsulphate polyacrylamide gel electrophoresis(SDS-PAGE) and mass spectrometry(MS) in 175 wild emmer accessions which were from German Munich Industrial university.These datas may facilitate basic research on the relationship of industrial quality with HMW glutenin subunit and could be used to broaden the genetic basis for wheat breeding.The main results obtained were as the followings:Separation and identification of HMW-GS by SDS-PAGEHMW-GSs in Triticum dicoccoides were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE) technique.36 allelic variations were found at Glu-1 locus,and four alleles were at the Glu-A1 locus:1,1~*,2~* and Null,32 alleles were at the Glu-B1 locus,a high degree of variation was evident for the HMW-GS in wild emmer accessions. The distribution of alleles appeared to be non random,the frequency of 7+8 and 14.1+15.1 were 20.0%,which were higher than others at the Glu-B1 locus.7 new allelic variations were found at Glu-B1 locus:1.1,5~*,7~*,12~*,14.1,15.1 and 16~*.Forty-four HMW glutenin subunit combinations have been observed at Glu-1 loci,of which the combinations(null,14.1+15.1) have accounted up to 12.58%.The results indicated that the combination of HMW is abundant among the tested wheat cultivars.Identification of HMW-GS by MALDL-TOF-MSThe accurate measurement of molecular weights and characterization of wheat HMW-GS through matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) was established in this study,which has the advantages of fast,simplified process,requirement of small samples and high resolution.The results show that HMW-GS components could be well characterized in the molecular weight range of 60-100kD.The molecular weight of the new subunits 1Bxl4.1,1By15.1,1Bx7~*,1By12~* and 1Bx1.1 which identified by MALDI-TOF-MS were 82.9419kD,73.3575kD,86.1045kD,71.0637kD and 88.4767kD respectively.