Search Results (920)

Background: Improving grain yield in wheat remains a top priority, requiring integrated breeding and genetic strategies. This complexity poses a major challenge, driven by quantitative polygenic inheritance, environmental influence, and intricate genetic interactions. We investigated genetic factors and their interactions for agronomic and yield traits in two high-yielding winter wheat cultivars adapted to the US Southern Great Plains. Methods: A bi-parental mapping population consisting of 221 F₇ recombinant inbred lines (RIL) derived from ‘TAM 204’ and ‘Iba’ was evaluated for three years in 11 Texas environments. Both parents and RIL population were genotyped on Illumina NovaSeq 6000 and sequences were aligned to IWGSC RefSeq v1.0 using Bowtie2 for SNP calling. For QTL analyses, each trait was analyzed by individual environment, across multiple environments and mega-environments. Results: A total of 86 QTL were mapped for five traits and among them 32 were consistent in more than one environment or analysis. Among consistent QTL, four were pleiotropic to more than one agronomic or yield traits mapped on chromosomes 2B (57.18, 59.47 Mb) and 2D (29.34, 40.64 Mb). The consistent QTL on chromosome 2D (29.34 Mb) was pleiotropic to GYLD, DTH, TW, TKW and explained maximum phenotypic variation for all traits, representing photoperiod gene (Ppd-D1). Another QTL on chromosome 2D (40.64 Mb) was pleiotropic to GYLD and TW and based on the physical position comparisons it likely reflects a unique locus in Iba. The pleiotropic consistent QTL Qgyld.tamu.2B.59 from TAM 204 represents Ppd-B1 gene. Moreover, it is more likely that Qdth.tamu.5B.575 represents the Vrn-B1 gene in Iba. A total of 23 digenic epistatic interactions involved consistent QTL for all traits. Amongst these, epistatic interactions between the consistent QTL on 2B (57.18 Mb) and 2D (29.34 Mb) were observed for GYLD, DTH and TKW. Conclusions: Our findings revealed key allelic diversity and interaction effects in elite wheat cultivars, paving the way for marker development for identified pleiotropic loci and implementation in marker-assisted selection and recombination breeding. Full article

Mixograph properties represent important quantitative traits that are controlled by multiple genes and influenced by environmental factors. In this study, we conducted quantitative trait locus (QTL) mapping for key Mixograph paraments using a recombinant inbred line (RIL) population derived from a cross between Yangxiaomai and Zhongyou 9507. Based on a high-density genetic map, six stable QTLs were identified on chromosomes 1A, 1B, and 1D across four environments, with individual phenotypic variation explained, ranging from 2.26 to 28.70%. Among these, QTh.ahau-1A, QMt/QPa.ahau-1B, and QTw.ahau-1D.1 are potentially novel loci. Furthermore, four functional Kompetitive Allele-Specific PCR (KASP) markers were developed based on tightly linked SNPs and validated in 110 advanced breeding lines, confirming their significant association with the target traits and utility for marker-assisted selection (MAS). Additionally, six candidate genes were predicted, which encoded proteins such as a hydroxyproline-rich glycoprotein, a CCCH-type zinc finger protein, protease, kinase, a phosphoglucan water dikinase, and a TRP-like family protein. Collectively, these findings provide valuable genetic loci, functional molecular markers, and candidate gene resources for improving wheat processing quality through MAS-based breeding. Full article

Wheat (Triticum aestivum L.) is one of the most cultivated crops in the world, but production is often affected by drought. The wheat chromosome 4A contains several quantitative trait loci (QTL) associated with drought tolerance and yield-related traits, making it a valuable target for genetic improvement. In this study, we developed near-isogenic lines (NILs) carrying qDT.4A.1, a major QTL for yield using a fast generation cycling system (FGCS) and characterized these NILs for grain yield and thousand-grain weight (TGW) under drought stress and control conditions. We identified a single nucleotide polymorphism (SNP) marker Kukri_c27037_112, which showed a consistent genotype–phenotype associations across two NIL pairs. This marker is linked to four candidate genes encoding a RING-finger E3 ubiquitin ligase, a receptor kinase, and a protein kinase family protein involved in drought stress response and pathways. In silico expression analyses revealed upregulation of these genes in grain tissue under drought conditions, supporting their potential role in grain development and yield formation during drought stress conditions. The identified SNP marker and its associated candidate genes are potential resources in marker-assisted selection and fine mapping pending further validation and functional studies. Our results provide valuable genomic resources, laying the foundation for the development of drought-tolerant wheat varieties and highlighting chromosome 4A as a key region governing drought tolerance. Full article

Nitrogen (N) availability is a critical determinant of grain yield and protein quality in wheat (Triticum aestivum L.). To elucidate the molecular mechanisms underlying nitrogen response associated with nitrogen use efficiency (NUE), a comparative transcriptomic analysis of high grain protein content (HP) and low grain protein content (LP) wheat lines during N resupply at the seedling stage is conducted in this study, with sampling conducted at T1 (one day after treatment) and T3 (three days after treatment). Our results reveal that the HP line exhibits an early-responsive and well-coordinated metabolic pattern, whereas the LP line shows a distinct temporal response characterized by delayed adjustments. Integrated GSEA and KEGG analyses demonstrated that the HP line prioritized protein processing in the endoplasmic reticulum and diterpenoid biosynthesis, potentially associated with enhanced protein quality control and early signaling efficacy. This allows the HP line to synchronize its N assimilation machinery with the transient peak of N availability at T1 and establishes a robust foundation for protein accumulation. Conversely, the LP line redirected its metabolic resources toward glutathione metabolism and flavonoid biosynthesis to mitigate N-induced oxidative instability. This metabolic shift increases the energetic usage required for antioxidant defense and subsequently deviates resources away from productive N assimilation. These divergent metabolic landscapes were orchestrated by a hierarchical network of transcription factors (TFs). In leaves, the MYB and NAC families showed a more disciplined and immediate increase in the HP line, whereas the LP line demonstrated a delayed peak at T3. In root tissues, while Dof and NAC families were rapidly induced and concluded in the HP line, the LP line exhibited a sluggish sensing-to-response mechanism with prolonged or specific late-stage activation at T3. These results indicate that the capacity for rapid metabolic synchronization and disciplined transcriptomic mobilization is a key physiological indicator of high-protein potential in wheat. This insight provides essential molecular targets for breeding programs aimed at improving NUE and grain quality. Full article

Stripe rust (Puccinia striiformis) and Fusarium head blight (FHB; caused by Fusarium graminearum) are fungal diseases that endanger wheat productivity; however, by pyramiding disease-resistant genes, the long-term resistance of wheat can be strengthened. In this study, a multi-parent pyramiding hybrid population was constructed using marker-assisted selection (MAS). After multiple generations of breeding, 168 F₆ lines were obtained. By combining molecular marker genotyping, field resistance identification, and agronomic trait evaluation, 19 lines with excellent agronomic traits were selected, which not only showed high resistance to stripe rust but also carried Fhb1 genes, some of which have the potential to be developed into new germplasms and offer important genetic resources for the breeding of wheat with long-lasting and broad-spectrum resistance. Full article

Maintaining stable male sterility is fundamental for ensuring the genetic purity and productivity of two-line hybrid wheat. However, unexpected heat events during the fertility-sensitive period can induce fertility restoration in photo-thermo-sensitive male sterile (PTMS) lines, posing a major threat to hybrid seed production. In this study, we identified two BS-type PTMS lines, BS166 and BS192, that consistently maintained sterility under heat stress in a seed-production environment, indicating strong heat-tolerant sterility. To uncover the molecular basis underlying this stability, we compared four BS-type PTMS lines exhibiting contrasting heat responses through field assessments, controlled heat treatments, transcriptome sequencing, and weighted gene co-expression network analysis (WGCNA). A total of 19,105 differentially expressed genes were identified, with the bisque4 module showing a significant correlation with seed setting rate. KEGG enrichment analysis revealed that starch and sucrose metabolism, cutin, suberin, and wax biosynthesis, fatty acid biosynthesis, and plant hormone signal transduction pathways were highly associated with heat-tolerant sterility. Core genes within these pathways displayed transcriptional stability in BS166 and BS192 but were strongly induced in heat-sensitive lines. In situ hybridization and RT-qPCR further confirmed tapetum-specific expression of TaBGLU32 and TaLACS1. Based on these findings, we propose a regulatory model explaining how PTMS lines maintain sterility stability under heat stress. Full article

This study used cryoSEM to analyze the seasonal stability of leaf surface micromorphology in cereal hybrids derived from crossing maternal ×Trititrigia cziczinii × Thinopyrum junceum lines with paternal wheat–wheatgrass hybrids. Over two growing seasons, relatively rare traits showed high stability, while most traits exhibiting initial diversity demonstrated seasonal variability. Paternal traits (hairs, prickles, elongated silica cells) predominated in hybrids, and hybrid diversity correlated significantly with paternal, but not maternal, line diversity. In 2025, a significant decrease in some paternally specific traits and an increase in rounded silica cells were observed compared to 2024. Coordinated dynamics were revealed: variations in maternal traits correlated positively with each other and negatively with some paternal traits. While certain micromorphological features exhibited relative stability, employing such traits for taxonomic purposes necessitates caution and a thorough understanding of their inherent variability ranges. Full article

Common wheat (Triticum aestivum L.) is a staple food crop for humans, yet it primarily accumulates the non-provitamin A carotenoid lutein and exhibits limited natural variation in provitamin A β-carotene among its various accessions. This characteristic necessitates the development of alternative strategies for provitamin A biofortification. To address this challenge, we targeted key control points in the carotenoid biosynthetic pathway using the CRISPR-Cas9 system in a wheat cultivar Fielder. Specifically, we knocked out the gene encoding lycopene ε-cyclase (LCYE), an enzyme that acts as a gatekeeper opposing the production of β-branch carotenoids. Biochemical analysis of homozygous transgene-free mutant endosperms at 20 days post-anthesis (DPA) revealed marked metabolic rerouting of carotenoid biosynthesis, characterized by differential, line-specific accumulation patterns. Provitamin A carotenoids—specifically β-carotene—increased by 26.1–34.5% relative to wild-type controls, concomitant with elevated 22.9–125.4% for zeaxanthin, 41.6–73.9% for violaxanthin, and 26.2–186.5% for antheraxanthin. However, these gains were offset by drastic lutein reduction in lines 1–4 and 5–1. Consequently, total carotenoid levels displayed non-uniform responses, with line 5–1 exhibiting a modest decrease relative to wild-type. Moreover, the mutant lines exhibited elevated levels of amylose and soluble sugar, and the seed coats and endosperms of the triple homozygous transgene-free mutant lines exhibited an orange-yellow hue. In conclusion, we have successfully developed novel carotenoids biofortified wheat lines through a gene-editing approach. This study demonstrates targeted redirection of carotenoid biosynthesis via gene editing as an effective strategy to enhance the nutritional value of commercial wheat and mitigate micronutrient deficiencies in modern food systems. Full article

Plant pathogens are a major cause of crop yield loss, making disease resistance breeding crucial for crop improvement. Plants have evolved innate immune systems, mediated by immune-related genes such as nucleotide-binding site leucine-rich repeat (NLR), pattern-recognition receptors (PRR) and susceptibility genes, which are essential resources for breeding disease-resistant plants. To identify immunity genes, extensive genetic approaches that examine the association between resistance phenotypes and genomic regions have been applied with great success. While genetic methods remain important for identifying immunity genes, novel strategies that rely on functional rather than genetic association with disease resistance offer unique advantages. For example, mutagenesis with R gene enrichment sequencing (MutRenSeq) enabled the identification of wheat resistance genes Sr22 and Sr45 by comparing the NLRomes of resistant and susceptible lines while single-cell RNA sequencing resolved cell-type-specific responses to pathogen infection and revealed ZmChit7, especially in maize epidermal and guard cells. These approaches reach beyond existing natural variation, can accelerate experimental timelines, reduce the experimental scale, and provide mechanistic insights into pathogen resistance. This review discusses emerging techniques that generate focused candidate immunity gene lists or accelerate their validation, as both are required to identify causal variants for resistance breeding. We consider advances in RenSeq-derived methods, spatial omics, proximity labelling, computational prediction, Clustered regularly interspaced short palindromic repeats (CRISPR) screens, and cell death assays. These approaches are reshaping resistance breeding pipelines beyond association-based discovery. By discussing the strengths and limitations of these emerging methods and their combinations, we outline current opportunities and future directions to help plant pathologists to more effectively identify and validate plant immunity genes. Full article

This study quantifies household-level socioeconomic drivers of food and nutrition insecurity in two rural Lesotho villages and translates those findings into clear monitorable pathways for sustainable development. Lesotho has a population of just over 2 million, of which 580,000 people live below the poverty line, and 24% (about 139,200) in the subset are experiencing extreme poverty, particularly in rural areas. Food and nutrition insecurity affects 61% of the population in rural areas and 39% in urban areas. The study aimed to determine the socioeconomic conditions and food security status of 126 females residing in Mpharane and Maqoala villages in the district of Mohale’s Hoek in Lesotho. A cross-sectional quantitative design was employed, and the measurement instruments included a socio-demographic questionnaire, the Household Hunger Scale (HHS), the Household Food Insecurity Access Scale (HFIAS), and a food frequency questionnaire. Statistical analyses were conducted using descriptive statistics. The results indicated that all the participants were mothers and caregivers living in overcrowded households, with 61% residing in one-room homes. Unemployment was a universal experience among the participants, resulting in severe food insecurity as 100% of the participants reduced the food intake of their children, as well as other household members, due to limited financial resources. The participants’ diet was predominantly cereal-based, with a mean cereal group intake of 26.70 (±8.53), and wheat was the most frequently consumed cereal (59.5%). By linking food security metrics (HHS, HFIAS, and food frequency) to household structure, unemployment, housing density, and cash access, the research produces evidence that can be used to design, prioritize, and evaluate interventions across the social, economic, environmental, and governance dimensions of sustainability. In conclusion, by defining measurable household-level links between socioeconomic conditions and food insecurity, this study provides baseline indicators and practical intervention targets aimed at achieving sustainable food systems, social equity, and economic resilience in rural Lesotho. Full article

YUCCA belongs to the flavin-containing monooxygenas and catalyzes the rate-limiting step in endogenous auxin biosynthesis, thereby regulating local auxin homeostasis and participating in diverse aspects of plant growth, development, and physiological processes. However, the relationship between the YUCCA genes and male fertility regulation in wheat remains unclear. In this study, we identified 64 TaYUCCA genes through whole-genome analysis and classified them into three clades, each of which is conserved in motif composition and gene structure. A synteny analysis indicated that family expansion was primarily driven by segmental duplication and tandem duplication, and Ka/Ks analysis suggested that all members are under purifying selection. An analysis of the expression patterns showed that the TaYUCCA genes displayed differential expression across various tissues and reproductive developmental stages. In the temperature-sensitive male-sterile wheat line YS3038, TaYUCCA19, TaYUCCA22, and TaYUCCA25 were specifically highly expressed at the uninucleate pollen stage under fertile conditions. The silencing of TaYUCCA19 resulted in abnormal pollen morphology and a significant reduction in the seed set rate, indicating that it is a key gene required for normal pollen development in wheat. Overall, this study systematically characterizes the wheat YUCCA gene family and provides the first functional evidence of TaYUCCA genes in male reproductive development, offering an important foundation for studies on wheat male sterility mechanisms and the exploitation of heterosis. Full article

Wheat seed quality is a key factor of end-use performance and nutritional value, yet it is strongly influenced by both genetic and environmental factors. The present study evaluated the performance, stability, and genetic control of wheat seed quality traits across six contrasting environments in Greece, focusing on genotypes derived from three selection designs (McGinnis & Shebeski, honeycomb, and gridding) and a local landrace. The measured traits included crude protein, fat, ash, starch, crude fibre, Zeleny sedimentation, carbohydrate, soluble fraction, non-starch fraction, and moisture. A combined ANOVA revealed significant effects of genotype, environment, and their interaction on all traits. Crude protein, fat, ash, and carbohydrate were predominantly governed by genotype, while starch, Zeleny sedimentation, soluble fraction, non-starch fraction, and moisture were more influenced by environmental factors, while crude fiber showed balanced genotype × environment effects. Stability analysis identified genotypes with consistent expression of key quality traits across environments, demonstrating the relevance of stability parameters for reliable selection. Correlation analysis indicated positive associations among protein, fat, Zeleny sedimentation, and crude fiber, and negative relationships with starch, carbohydrate, soluble fraction, and non-starch fraction, revealing trade-offs among wheat seed quality components. Selection method influenced trait expression, with gridding-derived lines excelling in protein and fat, McGinnis & Shebeski lines in Zeleny sedimentation and fiber, and honeycomb-derived lines in starch, carbohydrate, soluble, and non-starch fractions. Overall, the results support the use of multi-environment evaluation and stability-based selection to improve wheat seed quality in a predictable and targeted manner. Full article

Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is an important disease in wheat production. Breeding disease-resistant breeds is the most effective measure for preventing and controlling this disease. In this study, hybrid combinations were developed using wheat varieties Mianmai367 and Zhoumai22; 40059, 40047, and Zhoumai8425B. Mixed seed harvesting and artificial selection were conducted from the F₁ to F₄ generations, followed by manual screening of superior disease-resistant single plants in the F₅ generation to obtain 271 F₆ families. These F₆ families underwent molecular marker detection, disease resistance identification, and agronomic trait evaluation. The molecular markers included markers linked to YrZH84 (Xcfa2040, Xbarc32), YrZH22 (WGGB119, WGGB124), Yr30 (Xgwm533, We173), and Yr26 (Xbarc181). Through a comprehensive selection, wheat families with either single or multiple pyramided genes that exhibited both disease resistance and excellent agronomic traits were identified. Ultimately, 63 wheat families with excellent agronomic traits and disease resistance were selected. Among 63 pedigrees, there are three pedigrees containing four genes YrZH84, Yr30, YrZH22, and Yr26, four pedigrees containing three genes, 13 families containing two genes, 22 families containing one gene, and 21 families containing none of the genes. These families exhibit strong stripe rust resistance and superior agronomic characteristics, making them suitable for developing new wheat lines with durable resistance and high-yield potential. They thus provide effective materials for wheat breeding. Full article

Grain quality traits in wheat (Triticum aestivum L.), including protein content, gluten strength, and carbohydrate composition, are key determinants of end-use performance and breeding potential. This study assessed the genetic variability, stability, and multivariate relationships of seed quality traits among elite F7 pure lines derived from six long-term cultivated wheat cultivars. Field trials were conducted across six contrasting environments to evaluate genotype, environment, and genotype × environment (G × E) effects on crude protein, fat, ash, starch, crude fiber, Zeleny sedimentation, carbohydrates, non-starch carbohydrates, and moisture. Combined ANOVA revealed that genotypic effects accounted for the largest proportion of variation, though significant environmental and G × E effects were also observed. Broad-sense heritability was high for protein, Zeleny, and carbohydrate content. Stability analysis using the Stability Index (SI) highlighted A1, A2, A4, C2, E1, and F2 as genotypes combining high mean performance with a consistent expression across all environments. Principal component analysis (PCA) illustrated key trait relationships and trade-offs, particularly the negative association between protein-related traits and carbohydrate accumulation, while revealing the partial clustering of genotypes with similar quality profiles. AMMI and GGE biplots further supported broad adaptation for some genotypes (e.g., E1, F4, E2 for crude protein; F3, F4, E2 for Zeleny) and trait- or environment-specific performance for others. Correlation analyses confirmed positive associations between protein and gluten strength, and negative correlations with carbohydrate traits. Overall, targeted pure-line selection effectively exploits intracultivar genetic variation, offering a practical strategy for identifying superior, resilient wheat lines for breeding programs across diverse environments. Full article

Drought stress is a critical limiting factor for wheat yield. Wild relatives of wheat have proven to be valuable genetic resources for desirable traits. This study aimed to conduct a comparative analysis of agronomic traits, photosynthetic physiological parameters, and antioxidant components among 26 heterogermplasm wheat cultivars under well-watered (WW) and water-stressed (WS) conditions over two consecutive years. The results revealed that all nine agronomic traits were adversely affected under WS conditions. Four agronomic traits were selected based on the drought-resistance coefficient (DC < 0.8) and heritability (H² < 0.7) to calculate the membership function value of drought resistance (MFVD), including flag leaf area (FLA), tiller number (TN), grain yield per plant (GYPP), and biomass per plant (BMPP). All wheat genotypes clustered into three groups based on their mean value of MFVD in two years. Under drought stress, wheat germplasms classified within the high MFVD group demonstrate significantly enhanced drought adaptability, as evidenced by superior photosynthetic performance with elevated photosynthesis rate (Pn), the actual photochemical quantum efficiency of photosystem II (ΦPSII), and the electron transfer rate (ETR), increased chlorophyll retention (higher SPAD values), strengthened antioxidant enzyme activities, and reduced stomatal limitation. Correlation analyses further reveal that MFVD exhibits significant positive correlations with Pn, ΦPSII, ETR, SPAD, and key antioxidant enzymes, while displaying a significant negative correlation with stomatal limitation value (Ls). These consistent physiological and biochemical patterns corroborate that the constituent agronomic traits—tiller number (TN), flag leaf area (FLA), biomass per plant (BMPP), and grain yield per plant (GYPP)—serve as robust and integrated phenotypic indicators for comprehensively evaluating drought resistance in wheat germplasm. Among the evaluated lines, lines 6, 15, 17, 21, and 22 exhibited significantly higher levels of drought resistance. These results highlight the presence of genetic variability among heterogermplasm wheat cultivars, which can be harnessed in breeding programs to develop drought-tolerant wheat varieties. Full article