The Characteristics Of HMW-GS Of Some Common Wheat Core Germplasm In China And Its Correlation With Several Quality Traits

Wheat is one of the most important staple crops in the world.The improvement of living standards puts higher requirements on the quality of wheat.Quality genetic improvement has become a breeding target that wheat breeders are paying more and more attention to.High molecular weight glutenin subunit(HMW-GS)is an important component of wheat grain storage protein,and its content,type and composition characteristics determine the processing quality of wheat.In this experiment,294 Chinese core germplasm wheat varieties(lines)and five Huazhong Agricultural University self-bred wheat varieties were planted in the experimental field of Huazhong Agricultural University(Wuhan).The HMW-GS of 299 materials were identified by SDS-PAGE.Eight quality indicators of 294 Chinese core germplasm materials were determined by NIRS DS2500 NIR analyzer.They were starch content,protein content,falling value,hardness,bulk density,weakness,wet gluten content and Zeleny sedimentation value.The HMW-GS composition and genetic diversity of the tested materials were systematically analyzed,and the relationship between the composition characteristics of HMW-GS and some quality traits was analyzed.The main findings were as follows:1.HMW-GS subunit types: There were 17 types of HMW-GS in 299 wheat tested.At Glu-A1 locus,3 types of subunits including 1(31.10%),2*(3.68%),Null(65.22%)were detected,respectively;at Glu-B1 locus,9 types were found such as 7(5.69%),7+8(63.88%),7+9(20.07%),6+8(2.34%),20(2.34%),13+16(2.01%),14+15(2.68%),17+18(0.33%),22(0.67%);at the Glu-D1 locus,5 types including 2+12(58.19%),4+12(1.00%),5+10(11.04%),2+10(13.04%),5+12(16.72%)were detected.The four genetic diversity indices of the 299 tested wheats were: percentage of polymorphic loci(P)= 1.0000,alleles per locus(A)= 5.6667,and mean effective number of alleles per locus(Ae)= 2.2133 and index of genetic diversity(H)= 0.5423.It indicated that the Glu-1 locus of this population had high diversity,and the variation type of HMW-GS was abundant.2.Subunit combination types: There were 49 combination types of HMW-GS in 299 wheat tested materials,and the N/7+8/2+12 combination had the highest frequency,which was 37.46%,followed by 1/7+8/5+12(6.02%),1/7+8/2+12(5.69%),N/7+8/2+10(5.69%),N/7+9 /2+12(4.35%)and 1/7+9/2+12(4.01%)subunit combination types.Other subunit combination types appeared to have a lower frequency,and the frequency ranged from 0.34% to 2.68%.3.Cluster analysis results of HMW-GS allele combination: 49 HMW-GS alleles could be grouped into six classes with a similarity coefficient of 0.73.The first class contained four HMW-GS allele combinations.There were Glu-A1 a / Glu-B1 f / Glu-D1a?Glu-A1 a / Glu-B1 f / Glu-D1h?Glu-A1 c / Glu-B1 f / Glu-D1a?Glu-A1 c / Glu-B1 f / Glu-D1 e respectively.There were six varieties of this kind of wheat;The second type contained only one HMW-GS allele combination Glu-A1 c / Glu-B1 i / Glu-D1 a,the number of such wheat varieties was one;The third category contained four kinds of HMW-GS allele combination which were Glu-A1 a / Glu-B1 d / Glu-D1a?Glu-A1 c / Glu-B1 d / Glu-D1a?Glu-A1 c / Glu-B1 d / Glu-D1e?Glu-A1 c / Glu-B1 d / Glu-D1 d and there were seven wheat varieties in this category;The fourth category contains 20 HMW-GS allele combinations,the total number of such wheat varieties was 214;The fifth class contained 16 HMW-GS allele combinations,the number of such wheat varieties was 66;The sixth category contained four HMW-GS allele combinations,which were Glu-A1 a / Glu-B1 h / Glu-D1e?Glu-A1 a / Glu-B1 h / Glu-D1a?Glu-A1 a / Glu-B1 h / Glu-D1h?Glu-A1 b / Glu-B1 h / Glu-D1 h and the total number of such wheat varieties was five.4.Characteristics of quality traits of tested materials: Eight quality traits of 294 Chinese core germplasm wheat materials were measured and compared(grain starch content,protein content,falling value,hardness,bulk density,weakness,wet gluten content,Zeleny precipitation value),the number of varieties with a protein content of 14% or more was 40,accounting for 13.61%,the number of varieties with protein content less than 13% was 193,accounting for 65.64%;The number of varieties that content of wet gluten was greater than or equal to 32% was 30,accounting for 10.20%,the number of varieties with wet gluten content less than 28% was 148,accounting for 50.34%;the number of varieties with Zeleny precipitation value greater than or equal to 45 ml was 28,accounting for 9.52%,the number of varieties with Zeleny precipitation value less than 30 ml was 85,accounting for 28.91%;the number of varieties with a capacity greater than or equal to 770g/l was 290,accounting for 98.64%.At the same time,the eight quality traits were analyzed,and there were certain correlations among the eight quality traits.5.The relationship for several quality traits with subunit types and with subunit combinations: The main subunit type of HMW-GS of the tested materials had a certain relationship with the quality traits,there were some variations in the quality traits of different subunit variation types at the same locus of Glu-1 locus,and there were also different in the degree of variation of different quality traits.The positive effects of 14+15,7+9 and 5+10 subunits on bread wheat quality traits were higher;The effects of different HWM-GS combinations on protein content,falling value,bulk density and wet gluten content reached significant levels(0.05).The wheat varieties with 1/7+9/2+12 and N/7+9/5+10 subunits combination had higher protein content,falling value,bulk density and wet gluten content.The wheat varieties with N/7/2+12 subunit combination had relatively low protein content,falling value,bulk density and wet gluten content.