End-use Quality Research Articles

An elite γ-gliadin allele improves end-use quality in wheat.

Gluten is composed of glutenins and gliadins and determines the viscoelastic properties of dough and end-use quality in wheat (Triticum aestivum L.). Gliadins are important for wheat end-use traits, but the contribution of individual gliadin genes is unclear, since gliadins are encoded by a complex, multigenic family, including many pseudogenes. We used CRISPR/Cas9-mediated gene editing and map-based cloning to investigate the contribution of the γ-gliadin genes annotated in the wheat cultivar 'Fielder', showing that Gli-γ1-1D and Gli-γ2-1B account for most of the γ-gliadin accumulation. The impaired activity of only two γ-gliadin genes in knockout mutants improved end-use quality and reduced gluten epitopes associated with celiac disease (CD). Furthermore, we identified an elite haplotype of Gli-γ1-1D linked to higher end-use quality in a wheat germplasm collection and developed a molecular marker for this allele for marker-assisted selection. Our findings provide information and tools for biotechnology-based and classical breeding programs aimed at improving wheat end-use quality.

Targetedmutagenesis with sequence-specific nucleases for accelerated improvement of polyploid crops: Progress, challenges, and prospects.

Many of the world's most important crops are polyploid. The presence of more than two sets of chromosomes within their nuclei and frequently aberrant reproductive biology in polyploids present obstacles to conventional breeding. The presence of a larger number of homoeologous copies of each gene makes random mutation breeding a daunting task for polyploids. Genome editing has revolutionized improvement of polyploid crops as multiple gene copies and/or alleles can be edited simultaneously while preserving the key attributes of elite cultivars. Most genome-editing platforms employ sequence-specific nucleases (SSNs) to generate DNA double-stranded breaks at their target gene. Such DNA breaks are typically repaired via the error-prone nonhomologous end-joining process, which often leads to frame shift mutations, causing loss of gene function. Genome editing has enhanced the disease resistance, yield components, and end-use quality of polyploid crops. However, identification of candidate targets, genotyping, and requirement of high mutagenesis efficiency remain bottlenecks for targeted mutagenesis in polyploids. In this review, we will survey the tremendous progress of SSN-mediated targeted mutagenesis in polyploid crop improvement, discuss its challenges, and identify optimizations needed to sustain further progress.

Multiomics Based Association Mapping in Wheat Reveals Genetic Architecture of Quality and Allergenic Related Proteins.

Wheat is an important staple crop since its proteins contribute to human and animal nutrition and are important for its end-use quality. However, wheat proteins can also cause adverse human reactions for a large number of people. We performed a genome wide association study (GWAS) on 114 proteins quantified by LC-MS-based proteomics and expressed in an environmentally stable manner in 148 wheat cultivars with a heritability > 0.6. For 54 proteins, we detected quantitative trait loci (QTL) that exceeded the Bonferroni-corrected significance threshold and explained 17.3−84.5% of the genotypic variance. Proteins in the same family often clustered at a very close chromosomal position or the potential homeolog. Major QTLs were found for four well-known glutenin and gliadin subunits, and the QTL segregation pattern in the protein encoding the high molecular weight glutenin subunit Dx5 could be confirmed by SDS gel-electrophoresis. For nine potential allergenic proteins, large QTLs could be identified, and their measured allele frequencies open the possibility to select for low protein abundance by markers as long as their relevance for human health has been conclusively demonstrated. A potential allergen was introduced in the beginning of 1980s that may be linked to the cluster of resistance genes introgressed on chromosome 2AS from Triticum ventricosum. The reported sequence information for the 54 major QTLs can be used to design efficient markers for future wheat breeding.

Transcriptome and Proteome Analysis Revealed the Influence of High-Molecular-Weight Glutenin Subunits (HMW-GSs) Deficiency on Expression of Storage Substances and the Potential Regulatory Mechanism of HMW-GSs.

The processing quality of wheat is affected by seed storage substances, such as protein and starch. High-molecular-weight glutenin subunits (HMW-GSs) are the major components of wheat seed storage proteins (SSPs); they are also key determinators of wheat end-use quality. However, the effects of HMW-GSs absence on the expression of other storage substances and the regulation mechanism of HMW-GSs are still limited. Previously, a wheat transgenic line LH-11 with complete deletions of HMW-GSs was obtained through introducing an exogenous gene Glu-1Ebx to the wild-type cultivar Bobwhite by transgenic approach. In this study, comparative seed transcriptomics and proteomics of transgenic and non-transgenic lines at different seed developmental stages were carried out to explore the changes in genes and proteins and the underlying regulatory mechanism. Results revealed that a number of genes, including genes related to SSPs, carbohydrates metabolism, amino acids metabolism, transcription, translation, and protein process were differentially enriched. Seed storage proteins displayed differential expression patterns between the transgenic and non-transgenic line, a major rise in the expression levels of gliadins were observed at 21 and 28 days post anthesis (DPA) in the transgenic line. Changes in expressions of low-molecular-weight glutenins (LMW-GSs), avenin-like proteins (ALPs), lipid transfer proteins (LTPs), and protease inhibitors (PIs) were also observed. In addition, genes related to carbohydrate metabolism were differentially expressed, which probably leads to a difference in starch component and deposition. A list of gene categories participating in the accumulation of SSPs was proposed according to the transcriptome and proteome data. Six genes from the MYB and eight genes from the NAC transcription families are likely important regulators of HMW-GSs accumulation. This study will provide data support for understanding the regulatory network of wheat storage substances. The screened candidate genes can lay a foundation for further research on the regulation mechanism of HMW-GSs.

Wheat end-use quality: State of art, genetics, genomics-assisted improvement, future challenges, and opportunities.

Wheat is the most important source of food, feed, and nutrition for humans and livestock around the world. The expanding population has increasing demands for various wheat products with different quality attributes requiring the development of wheat cultivars that fulfills specific demands of end-users including millers and bakers in the international market. Therefore, wheat breeding programs continually strive to meet these quality standards by screening their improved breeding lines every year. However, the direct measurement of various end-use quality traits such as milling and baking qualities requires a large quantity of grain, traits-specific expensive instruments, time, and an expert workforce which limits the screening process. With the advancement of sequencing technologies, the study of the entire plant genome is possible, and genetic mapping techniques such as quantitative trait locus mapping and genome-wide association studies have enabled researchers to identify loci/genes associated with various end-use quality traits in wheat. Modern breeding techniques such as marker-assisted selection and genomic selection allow the utilization of these genomic resources for the prediction of quality attributes with high accuracy and efficiency which speeds up crop improvement and cultivar development endeavors. In addition, the candidate gene approach through functional as well as comparative genomics has facilitated the translation of the genomic information from several crop species including wild relatives to wheat. This review discusses the various end-use quality traits of wheat, their genetic control mechanisms, the use of genetics and genomics approaches for their improvement, and future challenges and opportunities for wheat breeding.

Molecular characterization and phylogenetic analysis of novel Wx genes from Psathyrostachys juncea and Eremopyrum bonaepartis

The ratio of amylose/amylopectin can greatly influence the end-use quality of wheat products, and amylose synthesis only needs the granule-bound starch synthase I that is encoded by the Waxy (Wx) gene. Hence, the Wx allele variability is a vital determinant of amylose synthesis. In this study, four novel Wx genes were isolated from two diploid Triticeae species. Their sequence variations were analyzed, which showed that the polymorphism among the Wx-F1 alleles was low; only seven single nucleotide polymorphisms (SNPs) and one amino acid (AA) residue change (Arg541 ? Cys) were detected in the exon regions, and this change in Wx-F1b was predicted to have deleterious effects on protein function. The two Wx-Ns1 alleles in this study were different from two published alleles obtained using three overlapping primer sets. The polymorphism among the four Wx-Ns1 alleles was high, and 37 SNPs and ten AA residue changes were found, while all of those substitutions were neutral. However, one substitution (Leu237 ? Pro) between Wx-H1 and Wx-Ns1 was predicted that would probably affect the protein function. Divergence time analysis showed that Wx-Ns1a diverged from Wx-Ns1b about 1.06 MYAs. Phylogenetic analysis indicated that Wx-F1 were more closely related to Wx-O1 from Henrardia persica, Wx-R1 from Secale cereale ssp. cereale, and Wx-Xe1 from Eremopyrum triticeum, while Wx-Ns1 were more closely related to Wx-H1 from Hordeum vulgare ssp. vulgare and Wx-Hch1 from Hordeum chilense. These genes may be important candidates for wheat quality improvement.

A study about factors influencing rice palatability based on changes in sensory and physicochemical properties under different postharvest conditions

Postharvest management plays a key role in determining the end-use quality of rice; therefore, a practical approach to inhibit quality deterioration is necessary. In this study, the effects of postharvest management—drying delay time (DDT) and moisture content after drying (DM) immediately after harvesting, and storage temperatures (ST) and periods (SP) of dried paddy rice—on the physicochemical, quality, and sensory properties of rice were comprehensively analyzed. Germination rate, seed viability, fat acidity, and sensory quality tended to significantly deteriorate with increasing DDT, DM, ST, and SP. The highest correlation (r = 0.8289) was observed between germination rate and sensory quality, indicating that germination rate can reliably predict sensory quality. Degradation of germination rate and overall sensory quality were analyzed: sensory quality exhibited a more gradual change than germination rate. Lastly, the effects of the postharvest conditions on overall sensory quality were predicted using a regression equation model. DDT, DM, and ST exhibited different patterns of change, which can be used to predict the sensory quality during storage. Germination rate was successfully applied as an influencing factor for the development of a rice-palatability prediction model. The results of this study are useful for maintaining fresh-rice palatability by preventing aging during postharvest storage.

Erosion of Quantitative Resistance in Wheat and Barley to fusarium Head Blight: Gene Pyramiding Achieves and Durability Study

Background: Fusarium head blight (FHB), caused by several fusarium species, is one of the diseases causing the greatest worldwide damage to small grain cereals, especially wheat and barley. FHB outbreaks can substantially diminish grain yield and end-use quality due to sterile florets and withered mycotoxin-contaminated grain kernels. Great effort has been accomplished to combat FHB in the past decades; however, solutions to prevent FHB damage are limited. The development of quantitative resistant cultivars is considered a sustainable and highly desired approach to reducing FHB damage. Objective: This review aims to combine novel data related to the potential ability of pathogens to evolve aggressiveness, erosion of quantitative head blight resistance in wheat and barley, and applying gene pyramiding which enhances host resistance to FHB infection to achieve durable head blight resistance. Results: Although FHB-resistance resources have been successfully utilized by resistant parents in wheat and barley breeding programs globally, this policy does not ensure high resistance to FHB since resistance will erode due to aggressiveness shifts of the head blight population. The increasing practice of monoculture wheat and barley cultivation has perhaps raised the rate of head blight pathogen evolution and obligated the natural balance shifting in favor of the pathogen, creating more repeated and grave epidemics, even in provinces where FHB has not been earlier recorded. More aggressive FHB populations have emerged in the field and under experimental laboratory conditions. It suggests adaptation followed by a spread of some strains in their environment, including adaptation to FHB-resistant breeds and possible erosion of wheat and barely resistance. Therefore, the pyramiding of several QTLs with high impact in one cereal cultivar may extend durability. Conclusion: If a pyramiding of multiple resistances improving QTL combined with selection against suspected susceptibility factors is achieved in novel cultivars, the evolution of FHB pathogens might be slowed owing to reduced exposure to the pathogen, disruptive selection on FHB populations and subsequently reduced fitness of fusarium fungi. This would stabilize the pathogen population and contribute to the durability of FHB resistance.

Comparison of the Phenotypic Performance, Molecular Diversity, and Proteomics in Transgenic Rice.

The extent of molecular diversity and differentially expressed proteins (DEPs) in transgenic lines provide valuable information to understand the phenotypic performance of transgenic crops compared with their parents. Here, we compared the differences in the phenotypic variation of twelve agronomic and end-use quality traits, the extent of microsatellite diversity, and DEPs of a recurrent parent line with three transgenic rice restorer lines carrying either CRY1C gene on chromosome 11 or CRY2A gene on chromosome 12 or both genes. The three transgenic lines had significantly smaller stem borer infestation than the recurrent parent without showing significant differences among most agronomic traits, yield components, and end-use quality traits. Using 512 microsatellite markers, the three transgenic lines inherited 2.9-4.3% of the Minghui 63 donor genome and 96.3-97.1% of the CH891 recurrent parent genome. As compared with the recurrent parent, the number of upregulated and down-regulated proteins in the three transgenic lines varied from 169 to 239 and from 131 to 199, respectively. Most DEPs were associated with the secondary metabolites biosynthesis transport and catabolism, carbohydrate transport and metabolism, post-translational modification, and signal transduction mechanisms. Although several differentially expressed proteins were observed between transgenic rice and its recurrent parent, the differences may not have been associated with grain yield and most other phenotypic traits in transgenic rice.

Organic Rice Production Practices: Effects on Grain End-Use Quality, Healthfulness, and Safety.

Demand for rice labeled as organic is growing globally. Consumers state that foods labeled as organic are nutritionally superior and safer than their conventionally produced equivalent. The research question for this systematic review is as follows: is there a difference between the effects of sustainable agriculture and conventional farming methods on rice grain end-use quality, healthfulness, and safety? The studies (n = 23) examined for this review suggest that organic production practices don't influence most end-use quality (e.g., chalk, milling yield, pasting properties) and healthfulness (e.g., gamma-oryzanol fraction and tocols) traits studied, or if it does, it will be to a small degree. If differences in end-use quality traits are found, they will be associated with grain protein content, which varies along with the dose of nitrogen applied during rice growth. We conclude that the studies evaluated in this review found that organically produced rice grain was less likely to contain residues of the pesticides (e.g., organochlorine) examined in the study than the rice is grown using conventional methods. There was some evidence that organically grown rice is more likely to be contaminated with mycotoxin-producing fungi and some mycotoxins. Common shortcomings of the studies were that they were poorly designed, with limited to no details of the cultural management practices used to grow the rice studied, the length of time fields was under organic management not stated, cultivars were not named, and the data wasn't analyzed statistically.

Prediction of near-term climate change impacts on UK wheat quality and the potential for adaptation through plant breeding.

Wheat is a major crop worldwide, mainly cultivated for human consumption and animal feed. Grain quality is paramount in determining its value and downstream use. While we know that climate change threatens global crop yields, a better understanding of impacts on wheat end-use quality is also critical. Combining quantitative genetics with climate model outputs, we investigated UK-wide trends in genotypic adaptation for wheat quality traits. In our approach, we augmented genomic prediction models with environmental characterisation of field trials to predict trait values and climate effects in historical field trial data between 2001 and 2020. Addition of environmental covariates, such as temperature and rainfall, successfully enabled prediction of genotype by environment interactions (G × E), and increased prediction accuracy of most traits for new genotypes in new year cross validation. We then extended predictions from these models to much larger numbers of simulated environments using climate scenarios projected under Representative Concentration Pathways 8.5 for 2050-2069. We found geographically varying climate change impacts on wheat quality due to contrasting associations between specific weather covariables and quality traits across the UK. Notably, negative impacts on quality traits were predicted in the East of the UK due to increased summer temperatures while the climate in the North and South-west may become more favourable with increased summer temperatures. Furthermore, by projecting 167,040 simulated future genotype-environment combinations, we found only limited potential for breeding to exploit predictable G × E to mitigate year-to-year environmental variability for most traits except Hagberg falling number. This suggests low adaptability of current UK wheat germplasm across future UK climates. More generally, approaches demonstrated here will be critical to enable adaptation of global crops to near-term climate change.

End-use quality of wheat affected by late maturity α-amylase

Late maturity α-amylase (LMA) is associated with elevated α-amylase within the aleurone of wheat grains. The increased α-amylase contributes to a reduced falling number (FN). A reduction in FN also results from preharvest sprouting and frost during grain fill which are associated with poor baking quality. Low FN can also lead to downgrading of wheat at grain receival sites, reducing returns for wheat growers. A population created to investigate LMA expression was used to assess the impact of LMA on dough rheology, pan bread and yellow alkaline noodles. Elevated levels of α-amylase due to LMA were found to have a negative impact on dough development time, stability and mixing tolerance index. Elevated α-amylase also led to darker crust colour and increased loaf volume, however, the improvement in loaf volume was less than that produced by bread improver. The increased α-amylase content associated with LMA also reduced the brightness of cooked and uncooked yellow alkaline noodles and the strength of overcooked noodles. The detrimental effect of LMA on dough rheology and yellow alkaline noodles means that flours produced from LMA-affected grain have reduced utility in some important wheat markets.

Survey on user perceived system factors influencing the QoE of audiovisual calls on smartphones.

With the widespread use of applications and services supporting audiovisual calls via smartphones, both in business and leisure contexts, a key challenge for service providers is meeting end user Quality of Experience (QoE) expectations and requirements. To successfully meet this challenge, there is a need to identify and analyze the key system-related factors impacting user perceived quality. In this paper, we contribute beyond state-of-the-art by conducting a large scale web-based questionnaire survey to investigate the system-related factors that subjects identify as most influential in contributing to their overall experience and quality perception. We focus in particular on leisure audiovisual calls, established via mobile devices. Our initial survey (Phase 1) was conducted in Feb. 2020, just prior to the outbreak of the COVID-19 pandemic (272 participants). To investigate if the importance of factors has changed due to increased usage of the service caused by the pandemic among the general population, we conducted a second survey (Phase 2) in October 2021 with 249 participants. Based on obtained results, we identify key system-related QoE influence factors belonging to three categories: media quality, functional support, and usability and service design. We observe no significant differences in user opinions and expectations prior to and during the period of increased service usage, despite different participant demographics and study time frames, thus contributing to generalizability of obtained results. Study results contribute to providing insights for designing future user studies investigating QoE, in terms of key factors that should be considered.

The end-use quality of wheat can be enhanced by optimal water management without incurring yield loss.

In China, water-saving irrigation is playing important roles in ensuring food security, and improving wheat quality. A barrel experiment was conducted with three winter wheat (Triticum aestivum L.) genotypes and two irrigation pattens to examine the effects of regulated deficit irrigation (RDI) on wheat grain yield, water-use efficiency (WUE), and grain quality. In order to accurately control the soil water content, wheat was planted in the iron barrels set under a rainproof shelter, and the soil water content in the iron barrel was controlled by gravity method. The mechanisms whereby water management influences the end-use functional properties of wheat grain were also investigated. The results revealed that RDI improved the end-use functional properties of wheat and WUE, without significant yield loss (less than 3%). Moderate water deficit (60% to 65% field capacity) before jointing and during the late grain-filling stage combined with a slight water deficit (65% to 70% field capacity) from jointing to booting increased grain quality and WUE. The observed non-significant reduction in wheat yield associated with RDI may be attributed to higher rate of photosynthesis during the early stage of grain development and higher rate of transfer of carbohydrates from vegetative organs to grains during the later stage. By triggering an earlier rapid transfer of nitrogen deposited in vegetative organs, RDI enhances grain nitrogen content, which in turn could enhance dough elasticity, given the positive correlation between grain nitrogen content and dough midline peak value. Our results also indicate that the effects of RDI on grain quality are genotype dependent. Therefore, the grain end-use quality of some specific wheat genotypes may be enhanced without incurring yield loss by an optimal water management.

Multigenerational elevated atmospheric CO2 concentration induced changes of wheat grain quality via altering nitrogen reallocation and starch catabolism

Previous studies indicated the grain yield and compositions of wheat (Triticum aestivum L.) were affected by long-term elevated atmospheric CO2 concentration conditions. However, the roles of protein expression in wheat grain quality changes under multigenerational elevated atmospheric CO2 concentration are still rarely known. This study explored that the changes of grain quality in wheat offspring induced by multigenerational elevated atmospheric CO2 concentration exposure and analyzed the roles of the differently expressed proteins using 4D proteomics in regulating the wheat grain quality. The changes of grain protein accumulation, gluten index and dough development time indicated that the nutritional and end-use quality of wheat grains were directly affected by elevated atmospheric CO2 concentration. This was mainly due to the changed expressions of α-amylase inhibitors, glutamine synthetase, glutamate dehydrogenase, formamidase and β-glucosidase, which regulated the starch accumulation and nitrogen metabolism in grains. This study elucidates the mechanisms underlying the effects of long-term elevated atmospheric CO2 concentration on wheat grain quality.

Identification and Introgression of a Novel HMW-GS Gene from Aegilops tauschii

High molecular weight glutenin subunits (HMW-GSs) play a major role in determining the dough quality of wheat. As the D genome donor of hexaploid wheat, Aegilops tauschii is an important genetic resource for wheat quality breeding. In the present study, a novel HMW-GSs from Ae. tauschii was identified and designated as Glu-Dt1. Multiple sequence alignment indicated that one cysteine was mutated into arginine in the y-type subunit. Site-directed mutagenesis technology was applied to verify the function of gene Glu-Dt1. Three introgression lines (ILs), B9, B25, and B35 with the Glu-D1 loci substituted by Glu-Dt1 were detected from the BC3F5 population derived from hexaploid wheat cultivar Jimai22 and Ae. tauschii Y215 through the direct hybridization approach. The dough quality and agronomic performance analysis were performed, which provide valuable resources for wheat genetic studies and breeding for distinctive end-use quality.

Transcriptome Analysis of Developing Grains from Wheat Cultivars TAM 111 and TAM 112 Reveal Cultivar-Specific Regulatory Networks.

Wheat flour’s end-use quality is tightly linked to the quantity and composition of storage proteins in the endosperm. TAM 111 and TAM 112 are two popular cultivars grown in the Southern US Great Plains with significantly different protein content. To investigate regulatory differences, transcriptome data were analyzed from developing grains at early- and mid-filling stages. At the mid-filling stage, TAM 111 preferentially upregulated starch metabolism-related pathways compared to TAM 112, whereas amino acid metabolism and transporter-related pathways were over-represented in TAM 112. Elemental analyses also indicated a higher N percentage in TAM 112 at the mid-filling stage. To explore the regulatory variation, weighted correlation gene network was constructed from publicly available RNAseq datasets to identify the modules differentially regulated in TAM 111 and TAM 112. Further, the potential transcription factors (TFs) regulating those modules were identified using graphical least absolute shrinkage and selection operator (GLASSO). Homologs of the OsNF-Y family members with known starch metabolism-related functions showed higher connectivities in TAM 111. Multiple TFs with high connectivity in TAM 112 had predicted functions associated with ABA response in grain. These results will provide novel targets for breeders to explore and further our understanding in mechanisms regulating grain development.

Effects of Cysteine and Inorganic Sulfur Applications at Different Growth Stages on Grain Protein and End-Use Quality in Wheat.

The aim of this study was to test the significant effects of inorganic sulfur and cysteine on grain protein and flour quality in wheat and to provide a theoretical basis of wheat cultivation techniques with high yield and quality. In the field experiment, a winter wheat cultivar, Yangmai 16, was used, and five treatments were established, i.e., S0 (no sulfur fertilizer application during the whole wheat growth period), S(B)60 (60 kg ha−1 inorganic sulfur fertilizer was applied as the basal fertilizer), Cys(B)60 (60 kg ha−1 cysteine sulfur fertilizer was applied as the basal fertilizer), S(J)60 (60 kg ha−1 inorganic sulfur fertilizer was applied as the jointing fertilizer), and Cys(J)60 (60 kg ha−1 cysteine sulfur fertilizer was applied as the jointing fertilizer). The fertilizer application at jointing stage showed a better influence than basal fertilizer application on protein quality; for the content of albumin, gliadin, and high molecular weight glutenin (HMW-GS), Cys(J)60 was the best among these treatments. An increase of 7.9%, 24.4%, 43.5%, 22.7% and 36.4% was found in grain yield, glutenin content, glutenin macro-polymer (GMP), low molecular weight glutenin (LMW-GS), and S content under Cys(J)60, in relation to the control, respectively. A similar trend was found in the end-use quality, as exemplified by an increase of 38.6%, 10.9%, 60.5%, and 109.8% in wet gluten content, dry gluten content, sedimentation volume, and bread-specific volume, respectively; a decrease of 69.3% and 69.1% in bread hardness and bread chewiness was found under Cys(J)60. In terms of application period, topdressing at jointing stage is compared with base fertilizer, the sulfur fertilizer application at jointing stage showed larger effects on grain protein and flour quality, from the different types of sulfur fertilizer, the application of cysteine performed better than the use of inorganic sulfur. The Cys(J)60 exhibited the best effects on protein and flour quality. It was suggested that sufficient sulfur application at jointing stage has the potential to enhance the grain protein and flour quality.

Identification of Glu-D1 Alleles and Novel Marker-Trait Associations for Flour Quality and Grain Yield Traits under Heat-Stress Environments in Wheat Lines Derived from Diverse Accessions of Aegilops tauschii.

Heat stress during grain filling is considered one of the major abiotic factors influencing wheat grain yield and quality in arid and semi-arid regions. We studied the effect of heat stress on flour quality and grain yield at moderate and continuous heat stress under natural field conditions using 147 lines of wheat multiple synthetic derivatives (MSD) containing Aegilops tauschii introgressions. The study aimed to identify the marker–trait associations (MTAs) for the quality traits and grain yield under heat-stress conditions and identify stress-resilient germplasm-combining traits for good flour quality and grain yield. The MSD lines showed considerable genetic variation for quality traits and grain yield under heat-stress conditions; some lines performed better than the recurrent parent, Norin 61. We identified two MSD lines that consistently maintained relative performance (RP) values above 100% for grain yield and dough strength. We found the presence of three high-molecular-weight glutenin subunits (HMW-GSs) at the Glu-D1 locus derived from Ae. tauschii, which were associated with stable dough strength across the four environments used in this study. These HMW-GSs could be potentially useful in applications for future improvements of end-use quality traits targeting wheat under severe heat stress. A total of 19,155 high-quality SNP markers were used for the genome-wide association analysis and 251 MTAs were identified, most of them on the D genome, confirming the power of the MSD panel as a platform for mining and exploring the genes of Ae. tauschii. We identified the MTAs for dough strength under heat stress, which simultaneously control grain yield and relative performance for dough strength under heat-stress/optimum conditions. This study proved that Ae. tauschii is an inexhaustible resource for genetic mining, and the identified lines and pleiotropic MTAs reported in this study are considered a good resource for the development of resilient wheat cultivars that combine both good flour quality and grain yield under stress conditions using marker-assisted selection.

Genetic dissection of QTLs for starch content in four maize DH populations.

Starch is the principal carbohydrate source in maize kernels. Understanding the genetic basis of starch content (SC) benefits greatly in improving maize yield and optimizing end-use quality. Here, four double haploid (DH) populations were generated and were used to identify quantitative trait loci (QTLs) associated with SC. The phenotype of SC exhibited continuous and approximate normal distribution in each population. A total of 13 QTLs for SC in maize kernels was detected in a range of 3.65–16.18% of phenotypic variation explained (PVE). Among those, only some partly overlapped with QTLs previously known to be related to SC. Meanwhile, 12 genes involved in starch synthesis and metabolism located within QTLs were identified in this study. These QTLs will lay the foundation to explore candidate genes regulating SC in maize kernel and facilitate the application of molecular marker-assisted selection for a breeding program to cultivate maize varieties with a deal of grain quality.