| The storage proteins in the wheat(Triticum aestivum L.) endosperm is one of the major vegetable proteins in food,and its kind and content decide the processing quality of flour,such as cooking performance,baking performance.The storage proteins in the wheat endosperm are divided into polymeric glutenins and monomeric gliadins for different solubility. Glutenin polymers are comprised of both high- and low molecular weight glutenin subunits.The quantity and composition of glutenin and gliadin,the interaction of glutenin and gliadin ,the interaction of glutenin and sugar and the interaction of gliadin and sugar are closely correlated with visco-elastic and extention properties of the dough deciding the wheat bread-making quality.Huanghuai wheat zone is one of the major producing areas in China,of which the wheat planting area accounts for about 40-44% and the production accounts for about 45% of the total.Recently,the breeding workers in Huanghuai wheat zone nurtured a lot of new varieties (lines).In order to understand the compositions of high-molecular-weight glutenin subunits(HMW-GS) of glutenin and gliadin in these new varieties(lines),and to master the current situation for breeding in Huanghuai wheat zone,the HMW-GS components of 105 new wheat varietiew(lines) were fractionated by SDS-PAGE . The newly found HMW-GS 5+12 was further confirmed at molecular level by Specific-PCR; the genetic diversity of gliadin in 106 new wheat varieties(lines) in Huanghuai wheat zone was analysed by A-PAGE.The rusults are as follows:1.The high-molecular-weight glutenin subunits(HMW-GS) components of 105 new wheat varieties(lines) were fractionated by SDS-PAGE in Huanghuai wheat zone.12 HMW-GS alleles were identified. Subunits 1,2﹡and Null at Glu-A1 were found with frequencies of 67.62%, 4.76% and 27.62%, respectively; subunits 7+8, 7+9, 14+15, 13+16, 13+19 and 17+18 at Glu-B1 with frequencies of 39.05%, 47.62%, 10.48%, 0.95%, 0.95% and 0.95%, respectively; and subunits 2+12, 5+12, 5+10 at Glu-D1 with frequencies of 46.67%, 26.67% and 26.67%, respectively. There are 23 types of subunits or combination of subunits. Among them are some good subunits or combinations of subunit, which could promote the quality of wheat-breeding, such as 5+12,5+10, 1,2﹡ 7+8, 14+15, 17+18,13+16. The pair of HMW-GS 5+12 at loci Glu-D1 newly found in common wheat is better for bread-making quality than 5+10 .These results reflect the composition of HMW-GS in new wheat varieties (lines) in Huanghuai wheat zone basically, but the frequencies of fine subunits for 5+10,2﹡are low. Therefore more excellent parents for wheat-breeding should be introduced and exploited in the future. 2. 28 new varieties(lines) among the researched materials whose pair of HMW-GS was identified to be 5+12 at loci Glu-D1 at protein level were tested by Specific-PCR.It was further confirmed that the pair of HMW-GS at loci Glu-D1 all of the 28 new varieties(lines) were 5+12 at molecular level.This result proves the existence of 5+12 in common wheat at molecular level,which will play an important role in evaluating the bread-making quality correctly.3. Gliadin variation of 106 new wheat varieties (lines) in huanghuai wheat zone were investigated by acid ployacrlamide gel electrophoresis(A-PAGE).The results are as follows:there are 106 gliadin patterns in the 106 materials,among which 63 gliadin bands are separated.Each advanced variety(line) has 10 to 24 bands.45 out of 106 varieties (lines)(42.5%) have the allele Gli-Bll,a marker of 1B/1R translocation chromosome.The genetic distance (GD) based on gliadin patterns ranges from 0.0287 to 1.00,with a mean value of 0.5703.Cluster analysis shows that the studied materials can be classified into 5 clusters at the level of GD 0.646.Based on these results.It is concluded that the new wheat varieties (lines)in Huanghuai wheat zone have respectively higher genetic diversity.
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