High-molecular-weight glutenin subunits (HMW-GSs) are the most critical grain storage proteins that determine the unique processing qualities of wheat. Although it is a part of the superior HMW-GS pair (Dx5+Dy10), the contribution of the Dy10 subunit to wheat processing quality remains unclear. In this study, we elucidated the effect of Dy10 on wheat processing quality by generating and analyzing a deletion mutant (with the Dy10-null allele), and by elucidating the changes to wheat flour following the incorporation of purified Dy10. The Dy10-null allele was transcribed normally, but the Dy10 subunit was lacking. These findings implied that the Dy10-null allele reduced the glutenin:gliadin ratio and negatively affected dough strength (i.e., Zeleny sedimentation value, gluten index, and dough development and stability times) and the bread-making quality; however, it positively affected the biscuit-making quality. The incorporation of various amounts of purified Dy10 into wheat flour had a detrimental effect on biscuit-making quality. The results of this study demonstrate that the Dy10 subunit is essential for maintaining wheat dough strength. Furthermore, the Dy10-null allele may be exploited by soft wheat breeding programs.

Increasing wheat yield is a long-term goal for wheat breeders around the world.  Exploiting elite genetic resources and dissecting the genetic basis of important agronomic traits in wheat are the necessary methods for high-yield wheat breeding.  This study evaluated nine crucial agronomic traits found in a natural population of 156 wheat varieties and 77 landraces from Sichuan, China in seven environments over two years.  The results of this investigation of agronomic traits showed that the landraces had more tillers and higher kernel numbers per spike (KNS), while the breeding varieties had higher thousand-kernel weight (TKW) and kernel weight per spike (KWS).  The generalized heritability (H²) values of the nine agronomic traits varied from 0.74 to 0.95.  Structure analysis suggested that the natural population could be divided into three groups using 43 198 single nucleotide polymorphism (SNP) markers from the wheat 55K SNP chip.  A total of 67 quantitative trait loci (QTLs) were identified by the genome-wide association study (GWAS) analysis based on the Q+K method of a mixed linear model.  Three important QTLs were analyzed in this study.  Four haplotypes of QFTN.sicau-7BL.1 for fertile tillers number (FTN), three haplotypes of QKNS.sicau-1AL.2 for KNS, and four haplotypes of QTKW.sicau-3BS.1 for TKW were detected.  FTN-Hap2, KNS-Hap1, and TKW-Hap2 were excellent haplotypes for each QTL based on the yield performance of 42 varieties in regional trials from 2002 to 2013.  The varieties with all three haplotypes showed the highest yield compared to those with either two haplotypes or one haplotype.  In addition, the KASP-AX-108866053 marker of QTL QKNS.sicau-1AL.2 was successfully distinguished between three haplotypes (or alleles) in 63 varieties based on the number of kernels per spike in regional trials between 2018 and 2021.  These genetic loci and reliable makers can be applied in marker-assisted selection or map-based gene cloning for the genetic improvement of wheat yield. 

Understanding the genetic basis of quality-related traits contributes to the improvement of grain protein concentration (GPC), grain starch concentration (GSC), and wet gluten concentration (WGC) in wheat, a genome-wide association study (GWAS) based on a mixed linear model (MLM) was performed on the 236 wheat accessions including 160 cultivars and 76 landraces using 55K single nucleotide polymorphism (SNP) array in multiple environments. A total of twelve stable QTL/SNPs were identified to control different quality traits in this populations at least two environments under stripe rust stress; three, seven and two QTLs associated with GPC, GSC, and WGC were characterized respectively and located on chromosomes 1B, 1D, 2A, 2B, 2D, 3B, 3D, 5D, and 7D with the range of phenotypic variation explained (PVE) from 4.2 to 10.7%. Compared with the previously reported QTLs/genes, five QTLs (QGsc.sicau-1BL, QGsc.sicau-1DS, QGsc.sicau-2DL.1, QGsc.sicau-2DL.2, QWgc.sicau-5DL) were potentially novel. KASP markers for SNPs AX-108770574 and AX-108791420 on chromosome on 5D associated with wet gluten concentration were successfully developed. Phenotype of the cultivars containing the A-allele in AX-108770574 and T-allele in AX-108791420 were extremely significantly (P<0.01) higher than that of the landraces containing the G-allele or C-allele of wet gluten concentration in each of the environments. The developed and validated KASP markers could be utilized in molecular breeding aiming to improve the quality in wheat.

Micronutrient malnutrition affects over three billion people worldwide, especially women and children in developing countries. Increasing the bioavailable concentrations of essential elements in the edible portions of crops is an effective resolution to address this issue. To determine the genetic factors controlling micronutrient concentration in wheat, the quantitative trait locus (QTL) analysis for iron, zinc, copper, manganese, and selenium concentrations in two recombinant inbred line populations was performed. In all, 39 QTLs for five micronutrient concentrations were identified in this study. Of these, 22 alleles from synthetic wheat SHW-L1 and seven alleles from the progeny line of the synthetic wheat Chuanmai 42 showed an increase in micronutrient concentrations. Five QTLs on chromosomes 2A, 3D, 4D, and 5B found in both the populations showed significant phenotypic variation for 2-3 micronutrient concentrations. Our results might help understand the genetic control of micronutrient concentration and allow the utilization of genetic resources of synthetic hexaploid wheat for improving micronutrient efficiency of cultivated wheat by using molecular marker-assisted selection.

Genetic diversity of 62 Sichuan wheat landraces accessions of China was investigated by agronomic traits and SSR markers. The landrace population showed the characters of higher tiller capability and more kernels/spike, especially tiller no./plant of six accessions was over 40 and kernels/spike of three accessions was more than 70. A total of 547 alleles in 124 polymorphic loci were detected with an average of 4.76 alleles per locus by 114 SSR markers. Parameters analysis indicated that the genetic diversity ranked as genome A> genome B > genome D, and the homoeologous groups ranked as 5>4>3>1>2>7>6 based on genetic richness (Ri). Furthermore, chromosomes 2A, 1B and 3D had more diversity than that of chromosomes 4A, 7A and 6B. The variation of SSR loci on chromosomes 1B, 2A, 2D, 3B, and 4B implied that, in the past, different selective pressures might have acted on different chromosome regions of these landraces. Our results suggested that Sichuan common wheat landraces is a useful genetic resource for genetic research and wheat improvement.

The Hina gene is one of the two known Hin genes for hardness, and its RNA expression is correlated with grain hardnessand dry matter digestibility variation. In this study, only one clone of Hina gene was obtained from one barley accession.A total of 121 Hina gene sequences were isolated from 121 wild barley (Hordeum spontaneum) accessions in Israel, Iran,and Turkey, and then their molecular characteristics were compared with 97 Hina gene sequences from 74 cultivatedbarley (H. vulgare) lines in Europe and 23 landrace (H. vulgare) with global distribution and other 26 Hina gene sequencesfrom cultivated barleys (H. vulgare) with unknown global distribution. Cis-acting regulatory element (CARE) searchingrevealed that there were different types of regulatory element for the Hina gene in wild and landrace/cultivated barleys.There were six consistent cis-acting binding sites in wild and landrace/cultivated barleys, whereas 8 to 16 inconsistentTATA-boxes were observed. In addition, three special elements (E2Fb, Sp1, and boxS) were only observed in wild barley,while one (AT1-motif) was only found in landrace/cultivated barley. Forty-four deduced amino acid sequences of HINAfrom wild and landrace/cultivated barleys were obtained by deleting repetitive amino acid sequences, and they wereclustered into two groups on the basis of Neighbor-Joining analysis. However, there was no obvious difference in theamino acid sequences of HINA between wild and landrace/cultivated barleys. Comparing to protein secondary structureof wheat PINA, it was indicated that HINA also existed a signal peptide. In addition, HINA was a hydrophilic protein onthe basis of the protein properties and composition.