Identification And Application Of NGli-D2、Sec-1^S And HMW-GS In Wheat

The composition and proportion of storage protein are the key factors affecting wheat processing quality,and the main components of storage protein are gluten and gliadin.The introduction of high-quality subunits or high-quality loci deletion lines provides a new idea for wheat quality improvement.The improvement of wheat processing quality can meet the needs of people’s life and has strong practical significance.The 1Dx5+1Dy10 and 1Dx5+1Dy12 subunits of HMW glutenin subunit were positively correlated with wheat quality.The introduction of NGli-D2 locus can increase Gli/Glu and improve dough quality.The introduction of Sec-1^Slocus can effectively reduce the negative effects of secalin on wheat processing quality in 1B/1R ectopic line.The polymeric types were identified by molecular markers,and the effects of different NGli-D2,Sec-1^Sand 1Dx5+1Dy10 polymeric genes on quality traits were analyzed under different genetic backgrounds,and the agronomic traits and frost resistance of polymeric resource materials were preliminatively evaluated.At the same time,49 sister lines of the new wheat variety Shannong 44 were used as test materials.The HMW-GS components were identified by SDS-PAGE,and the related quality traits were determined,and the quality effects of different subunit combinations were analyzed.The main results are as follows:1.Genetic polymeric materials obtained under different genetic backgrounds:a total of936 individual lines of genetic polymeric materials were obtained through random sampling identification.The polymerization rate of typeⅠdimer（1Dx5+1Dy10 and NGli-D2）was82.9%in Zhengmai 366 genetic background.Under the genetic background of Zhengmai7698,the polymerization rate of typeⅡdimer（1Dx5+1Dy10 and Sec-1^S）reached 92.6%.The polymerization rate of trimer（1Dx5+1Dy10,NGli-D2 and Sec-1^S）was 84.1%.In Hengguan35 genetic background,the polymerization rate of typeⅠdimer（1Dx5+1Dy10 and NGli-D2）and typeⅡdimer（1Dx5+1Dy10 and Sec-1^S）reached 90.7%and 96.3%respectively.The polymerization rate of trimer（1Dx5+1Dy10,NGli-D2 and Sec-1^S）was 81%.Fourteen different types of gene aggregates with outstanding comprehensive traits were obtained,which are participating in the test of strain identification and comparison.2.Analysis of the quality effect of gene aggregates:There were some differences in the performances of dimer and trimer under the same background,but the sedimentation value and kneading parameters（MPT,MPV,MPW,CTV,CTW,MTx V,MTx W and MTx I）of the polymers under the three different genetic backgrounds were significantly improved compared with the control,and the kneading resistance of flour was improved.The protein components（Glu/Gli and UPP%）were also increased,the gluten strength was enhanced,and the processing quality of genetically polymerized flour was improved.3.Analysis of agronomic traits and frost resistance of gene polymeric:The spike length,spikelet number,grain number per spike,plant height and 1000-grain weight of gene polymeric lines had no change compared with the control,and some agronomic traits of gene polymeric were slightly improved compared with the control.Therefore,gene aggregation did not negatively affect agronomic traits.In terms of frost resistance,different genetic backgrounds showed different performance of each gene polymeric,and the overall frost resistance was good,but the three gene polymeric exhibited the worst frost resistance under the background of Hengguan 35,and the grade 4 frost damage reached 66.6%.4.HMW-GS identification of shannong 44 sister line:There were two types of HMW-GS combinations,among which 1/7+8/5+10 was the dominant subunit composition of sister lines,accounting for 91.84%,while 1/7+8/5+10 subunit was less frequent,accounting for only 8.16%.Both of the two subunits were high-quality subunit combinations,which could be used as high-quality germplasm resources for wheat quality genetic improvement.5.Quality effect analysis of HMW-GS of Shannong 44 sister line:49 sister lines of the new wheat variety shannong 44 had large coefficient of variation in settling value,formation time,stabilization time,UPP%,Glu/Gli,MPT,MPW,CTW and MTx W,which showed great difference among different lines and had great improvement potential.The 1/7+8/5+12subunit combined wheat lines and 1/7+8/5+10 subunit combined wheat lines had advantages in different quality parameters,and 1Dx5+1Dy12 subunit was significantly better than1Dx5+1Dy10 subunit in Zeleny sedimentation value index.The MPW of 1Dx5+1Dy10subunit was significantly better than that of 1Dx5+1Dy12 subunit.Therefore,in the actual production process,the overall quality of the variety can not be predicted only by the single HMW-GS type character,but also need to be combined with other quality traits to judge.