Quality Performance Of Wheat Varieties In Henan Province And Their Relationship With The LMW-GS Genes

Wheat is the main food crop in Henan Province,and wheat quality is very important with the continuous increase of yield.In recent years,the quality of wheat in Henan Province has been greatly improved,but there are still some problems such as some high yield varieties with poor quality or high quality varieties with lower and instabile yield.The study of the internal mechanism of wheat quality and the molecular mechanism related to the control of wheat processing quality can provide more theoretical basis for wheat quality improvement.Therefore,the quality of 176 wheat cultivars(lines)planted in Henan Province,such as protein content,wet gluten content,SDS sedimentation value,Farinograph and Mixograph index,were tested,and the LMW-GS gene composition was analyzed by 2-generation sequencing method.The relationship between low molecular weight glutenin subunit gene and quality was analyzed.The main results and conclusions are as follows:1.Flour protein content ranged from 7.53% to 15.34% with an average of 12.02%,wet gluten ranged from 26.70% to 46.00% with an average of 33.28%,SDS sedimentation value from 6.66 ml to 31.05 m L with an average of 18.99 m L,dough stability time from 1.0-29.90 min with an average of 4.63 min.Of these wheat varieties,63 were weak dough samples(stability time ≤ 2.5 min),80 were medium dough(2.5 min<stability time<7.0 min),and only 33 were strong dough(7.0 min≤stability time).The average dough stability time released during 1980-2002,2003-2008 and2009-2014 was 4.35 min,4.41 min and 5.73 min,respectively,while that of varieties released in2015 and 2016 was 3.95 min.It revealed that the varieties in Henan Province mainly belonged to weak or medium dough quality,but the number of varieties with good quality increased greatly after2000.Pedigree analysis showed that most quality varieties were the progenies of Xiaoyan 6 and its sib-lines,indicating that those were the donor of good quality in Henan wheat varieties.Moreover,positive linear relationships were found between Mixograph parameters,e.g.peak time,peak value,and tail width,and Farinograph parameters,e.g.dough development time,dough stability time.Mixograph can be used to fastly test the dough quality.2.the LMW-GS gene composition of 176 wheat materials showed that 6 LMW-GS genes were detected at Glu-A3 locus,and at least 2 alleles of each LMW-GS gene appeared.There were 4 allele variants at A3-620 allele.There were 12 combinations of LMW-GS genes at Glu-A3 loci with different allelic variations.Among them,The highest proportion is A5(391,400,502,620)combination type(33.52%).At the Glu-B3 locus,6 LMW-GS genes were detected.The allele was B3-544 with 5 alleles.The frequency of B10 combinations was the highest with 52.27% at the Glu-B3 locus,and 8 LMW-GS genes were detected at Glu-D3 locus.Seven allelesof D3 gene was found,among them,The frequency of D3-583 gene was the highest with 52.84%.The genotype of The frequency of D11 among the compositions at the Glu-D3 locus was the highest with 36.93%.(3)The relationship between LMW-GS gene and quality showed that positive effect of A9 combination and negative effect of A8 combination on the wet gluten content was found at the Glu-A3 locus.At the Glu-B3 locus,B10 combination had a significant negative effect on quality,B4 combination had significant positive effect on SDS sedimentation value and right width,and B9 combination had significant positive effect on Stability time.At Glu-D3 locus,D5 combination had significant negative effect on the development time,and D2 combination had significant negative effect on peak value.D18 was good quality subunit gene combination,and had significant positive effects on development time,stability time and peak value.In addition,the effect of different LMW-GS gene combinations on quality was significantly different.The LMW-GS gene composition A5 + B10 + D8 had significant positive effect on the development time,while A11 +B10 + D11 gene combination had negative effect on development time.The LMW-GS gene composition A5 + B10 + D11 had significant negative effect on stability time,while A12 + B2 + D4 had better positive effect on stability time than others LMW-GS gene combination.