Disease resistance is crucial for minimizing agricultural inputs and safeguarding food supply to solve world hunger. The genetic diversity of wild relatives provides a valuable resource for enhancing the disease resistance and yield of crops such as common wheat (Triticum aestivum). Psathyrostachys huashanica (2n = 2x = 14, NsNs) is a valuable wild germplasm for wheat improvement because of its resistance to various diseases and abiotic stresses. Here we report that WPh13-2, a wheat-P. huashanica distant hybridization progeny, exhibited exceptional resistance to wheat powdery mildew (PM) at both seedling and adult stages. Genome in situ hybridization (GISH) revealed a karyotype of 2n = 42 = 21 II in WPh13-2 that carries one pair of alien chromosomes from P. huashanica. Preliminary evidence from fluorescence in situ hybridization (FISH) and molecular marker analysis indicated that the P. huashanica 5Ns chromosome substituted the wheat 5D chromosome in WPh13-2. The SNP array analysis demonstrated that the genotypes of most loci on the 5D chromosome of WPh13-2 were the same as in P. huashanica but different from those of the wheat parent, confirming the replacement of the 5D chromosome with the 5Ns chromosome in WPh13-2. Analysis of PM resistance in the F2 population (MX169 × WPh13-2) located the PM resistance gene(s) on the 5Ns chromosome. Finally, a 5Ns chromosome-specific kompetitive allele-specific (KASP) marker was developed for molecular assistant selection of the 5Ns chromosome. WPh13-2 will be a promising bridging germplasm for introgression of the PM resistance gene(s) into wheat breeding programs.

A nuclear-localized G2-like transcription factor, TaGLK-A1 (TraesCS7A02G539600), was identified as a strong candidate gene for grain fructan content in wheat using GWAS, linkage mapping and transcriptome analysis. Fructans, a type of natural polysaccharides or oligosaccharides polymerized from fructose molecules, play important physiological roles in crops and confer great health benefits to humans. In this study, we detected 78 stable loci associated with fructan content across all 21 wheat chromosomes across three environments and in the BLUE, explaining 4.4–10.0

Wheat is a major staple food and primary source of dietary minerals in the world, providing vital trace elements. Copper (Cu) is an essential nutrient for the development, and it plays a crucial role in various metabolic and biochemical reactions in wheat. Meanwhile, Cu is distributed in human tissues and organs and involved in human physiological functions. Cu deficiency may lead to abnormal hair, anemia, abnormal bones and even disorders of brain function. In this study, we detected QTLs for Cu content in two recombinant inbred line (RIL) populations, including 164 F6 RILs from a cross between Avocet and Chilero (AC population) and 175 F6 RILs from a cross between Avocet and Huites (AH population). Four QTLs (QGCu.haust-AH-7D, QGCu.haust-AC-5B.2, QGCu.haust-AH-5B.1, QGCu.haust-AH-1B) were detected on chromosomes 1B, 5B and 7D across more than two environments by QTL mapping with diversity array technology (DArT) marker. QGCu.haust-AH-7D, a major and stable QTL was detected in three environments explaining the phenotypic variance (PVE) from 8.70 to 9.34% with a physical interval of 99.96 to 100.66 Mb. QGCu.haust-5B, a co-localization and major QTL ranged from 446.01 to 450.57 Mb and explained 11.28% to 26.02% of the phenotypic variance between QGCu.haust-AC-5B.2 (421.44-607.84 Mb) in AC population and QGCu.haust-AH-5B.1 (446.01 to 450.57 Mb) of AH population in two environments. QGCu.haust-AH-1B, a stable QTL was explained 9.79 to 15.96% of the phenotypic variance with a physical interval of 340.46 Mb to 416.77 Mb in two environments. These favorable alleles of QGCu.haust-AH-1B, QGCu.haust-5B and QGCu.haust-AH-7D significantly increased grain Cu content by 13.63, 14.34 and 10.54% (P<0.01) compared with lines carrying unfavorable alleles. Using pyramiding and pleiotropic effects analysis with quality traits, the pyramiding of favorable alleles of the three QTLs significantly increased grain Cu content, grain protein content, wet gluten content and sedimentation value by 30.82, 18.65, 19.16, and 52.43% (P<0.01), respectively. A high-throughput competitive allele specific PCR (KASP) marker, KACu-5B-2 was developed and verified in the natural population (ZD population). Genetic effect revealed that favorable haplotype Hap1 significantly rised up grain Cu content, grain protein content, wet gluten content and sedimentation value by 8.1%, 5.12, 5.32, and 5.52% compared to Hap2 with unfavorable haplotype (P<0.05). This study provides a theoretical basis and technical support for cloning wheat grain Cu content related genes, facilitating molecular marker-assisted selection (MAS) and optimizing Cu-enriched biofortification breeding strategies.

Genetic diversity constraints in bread wheat (Triticum aestivum L.) severely limit progress in quality breeding. Chromosome introgression from wild relatives through distant hybridization represents a cutting-edge strategy to overcome these bottlenecks. Leymus mollis (NsNsXmXm) emerges as a key genetic resource due to its elite quality-related alleles. This study systematically evaluated the impact of L. mollis 1Ns chromosome introgression on gluten microstructure and processing traits in WL10-2, a wheat-L. mollis 1Ns substitution line. Compared to the parental cultivar 7182, WL10-2 exhibited higher grain protein content and glutenin macropolymer (GMP) content; increased accumulation rates of large protein bodies (PBs); an optimized secondary structure and gluten microstructure; and improved rheological properties and thermal stability of the dough. These results demonstrate that the 1Ns chromosome synergistically improves dough quality by remodeling protein secondary structures, promoting GMP polymerization, and optimizing gluten-starch spatial interactions, thereby providing both theoretical insight and breeding material for broader wheat adaptability.

Introduction:Magnesium transporters (MGTs) are crucial for Mg²⁺ uptake, transport, and storage. Although MGT family has been characterized in many plants, genome-wide identification and functional analysis of MGTs in wheat (Triticum aestivum L.) remain largely unclear. Methods:In this study, we identified wheat MGT genes using comparative genomics, and further analyzed their phylogeny, gene structure, conserved motifs, subcellular localization, gene duplication, protein-protein interactions, and expression patterns. Tissue-specific expression was verified by qRT‑PCR. Results:A total of 63 TaMGT genes were identified and classified into MRS2, CorA, and NIPA subfamilies. Most TaMGT proteins were predicted to target membrane systems. A total of 200 magnesium transporter genes were found considered to be generated by gene duplication events, and 1045 interacting proteins were predicted. TaMGT genes were highly expressed in flowering anthers. qRT‑PCR confirmed that 24 TaMRS2 genes exhibited obvious tissue specificity, with higher expression in leaves, stems, and spikes than in roots. Discussion:This study systematically reveals the evolutionary characteristics and functional differentiation of wheat MGT genes, and supports their important roles in reproductive growth. Our results provide a theoretical basis for further functional studies of magnesium transporters in wheat.

Replacing wheat chromosome 1D with its relative Leymus mollis chromosome 1Ns facilitates the incorporation of storage protein subunits, thereby improving the grain quality of wheat. Wild relatives of wheat serve as valuable gene pools for enhancing genetic diversity of wheat. Leymus mollis Trin. (L. mollis, 2n = 4x = 28, NsNsXmXm) exhibits multiple advantageous traits including disease resistance, stress tolerance, and high grain quality, rendering it a promising genetic resource for wheat improvement via distant hybridization. In this study, 82 wheat–L. mollis derivatives were assessed for grain quality. The superior line WM24 was further analyzed using biochemical, molecular, and cytogenetic methods. Seed storage protein electrophoresis revealed that improved quality of WM24 stems from introducing high-molecular-weight glutenin subunits and gliadins from L. mollis. Genomic in situ hybridization (GISH) confirmed that the chromosomal composition of WM24 was 2n = 42 = 21 II, including a pair of homologous chromosomes from Ns genome of L. mollis. The combination of molecular markers and sequential FISH–GISH indicated that WM24 carries two 1Ns chromosomes substituting for wheat chromosome 1D. SNP array analysis showed predominantly deletion (NA) genotypes of SNPs at 1D loci, corroborating the substitution event. These findings demonstrate that the introducing of L. mollis chromatin positively influences wheat grain quality. WM24 is a wheat–L. mollis 1Ns (1D) substitution line with higher protein content and sedimentation value due to altered storage protein profiles, resulting in enhanced quality traits. The development of these derivatives provides valuable germplasms for wheat quality breeding and exploration of novel exogenous quality-related genes.

A novel gene, TaqW-6AS was discovered on chromosome 6AS which encodes a Class III heme peroxidase influencing WE-AX content in wheat grain. Water-extractable arabinoxylan (WE-AX), a key soluble dietary fiber component, provides various significant health benefits and exhibits notable functional properties. In this study, we detected QTLs for WE-AX content in two populations: a natural population of 163 varieties (ZZ population) genotyped with the Axiom wheat 90 K single nucleotide polymorphism (SNP) array, and a recombinant inbred line (RIL) population with 175 lines derived from a cross between Avocet and Huites (AH population) genotyped with diversity array technology (DArT). QWE-AX.haust-6A, a major-effect and stable co-localized locus associated with WE-AX content was detected by GWAS and linkage analysis which was on the short arm of chromosome 6A with the physical interval 1.09 Mb from 14.61 to 15.70 Mb in five environments. In the candidate region of QWE-AX.haust-6A, a gene temporarily named TaqW-6AS was cloned, which encodes a Class III heme peroxidase. TaqW-6AS protein was localized in the ER-Golgi secretory pathway. Furthermore, three functional markers (kasp-qw6A-1, kasp-qw6A-4, and kasp-qw6A-6) and two favorable haplotypes (Hap4 and Hap5) of TaqW-6AS were deployed effectively in marker-assisted selection (MAS) for biofortification breeding.

Enhancing flag leaf nitrogen use efficiency (NUE) in wheat production can substantially increase crop productivity while minimizing nitrogen application. Quantitative trait loci (QTLs) for NUE-related have been rarely reported in wheat flag leaf traits. In this study, a natural population of 243 varieties and an RIL population of 123 F7 recombinants were subjected to different nitrogen treatments. A genome-wide association study (GWAS) and linkage analysis were performed for four agronomic traits in terms of flag leaf length, flag leaf width, flag leaf area, and SPAD (chlorophyll content) under low and normal nitrogen conditions. Through GWAS, 1,016 significant SNP loci were identified and clustered into 290 QTLs, including 11 stably mapped QTLs (stable detection in multiple environments). Additionally, an AC population was established to verify the GWAS results and identify reliable QTL intervals. Three stable loci, namely, QFLLR6D.3 QFLWR6A.6, and QSPADR5B.3, were validated in the AC population, located 1.34 Mb, 2.84 Mb, and 5 Mb away from linkage mapping significant QTL, respectively. Through further transcriptome analysis of Chilero leaves at the jointing, anthesis and grain filling stages, four DEGs were identified within QSPADR5B.3. Among them, TraesCS5B02G394300, TraesCS5B02G394200, and TraesCS5B02G39390 encode beta-glucosidases, and TraesCS5B02G396400 encodes a potassium channel. These findings offer potential candidate genes for wheat breeding, and provide a foundation for exploring the molecular targets underlying wheat NUE.

Zinc is an essential microelement of enzymes and proteins in wheat grains and humans. A deficiency in zinc content can lead to decreased wheat yield and low zinc content in grains, which in turn leads to insufficient dietary zinc intake. One recombinant inbred line (RIL) population derived from crosses Avocet/Huites (AH population) was used to map QTL for grain zinc content (GZnC) using diversity array technology (DArT). Nine QTLs were identified on chromosomes 2D, 3B, 4A, 4D, 5A, 5B, 6A, 7A, and 7D. Among them, QGZn.haust-AH-2D was detected in multiple environments, accounting for 5.61% to 11.27% of the phenotypic variation with a physical interval of 13.62 Mb to 17.82 Mb. Meanwhile, a genome-wide association study (GWAS) (CH population) comprising 243 cultivars or advanced lines revealed some genetic loci associated with zinc content in the wheat 660K single-nucleotide polymorphism (SNP) array. This was also identified within the physical interval of 13.61 Mb to 15.12 Mb of chromosome 2D, which accounted for 8.99% to 11.58% of the phenotypic variation in five models. A high-throughput competitive allele specific PCR (KASP) marker was developed, which verified the wheat natural population (NA population). QGZn.haust-AH-2D was fine mapped into a narrow region named TaZn-2DS between KAZn-2D-3 and 1111273 at a physical distance of 2.70 Mb, and the genetic effect of TaZn-2DS was 11.43%. This study shows that TaZn-2DS is associated with zinc content, and develops KAZn-2D-3 markers for the genetic improvement of nutritional quality in wheat.

Wheat (Triticum aestivum L.) is one of the most important staple crops in the world. Iron (Fe) plays a vital role in the growth and development of wheat as an essential nutrient. Meanwhile, Fe is closely associated with human health, as Fe deficiency anemia can cause fatigue, weakness, heart problems, and so on. In this study, quantitative trait loci (QTLs) for grain Fe content (GFeC) were detected in two populations: a recombinant inbred line (RIL) population with 175 lines derived from a cross between Avocet and Huites (AH population) genotyped with diversity array technology (DArT) and a natural population of 243 varieties (CH population) genotyped by using the 660K single-nucleotide polymorphism (SNP). Three stable QTLs (QGFe.haust-AH-5B, QGFe.haust-AH-6A, and QGFe.haust-AH-7A.2) were identified through QTL mapping with phenotypic variations of 11.55–13.63%, 3.58–9.89%, and 4.81–11.12% in the AH population in four environments. Genetic effects of QGFe.haust-AH-5B, QGFe.haust-AH-6A, and QGFe.haust-AH-7A.2 were shown to significantly increase GFeC by 8.11%, 14.05%, and 5.25%, respectively. One hundred and thirty-three significant SNPs were identified (p < 0.001) through a genome-wide association study (GWAS) for GFeC on chromosomes 1B, 2B, 3A, 3B, 5D, and 7A with phenotypic variations of 5.26–9.88% in the CH population. A novel locus was co-located within the physical interval 689.86 Mb-690.01 Mb in five environments through QTL mapping and GWAS, with one high-confidence gene, TraesCS7A02G499500, which was temporarily designated as TaqFe-7A, involved in GFeC regulation. A Kompetitive allele-specific PCR, KAFe-7A-2, was developed, which was validated in 181 natural populations. Genetic effect analysis revealed that favorable haplotype AA significantly increased GFeC by 4.64% compared to an unfavorable haplotype (p < 0.05). Therefore, this study provides the theoretical basis for cloning the GFeC gene and nutritional fortification breeding.

Genome‑wide association studies, linkage mapping and transcriptomic analysis reveal TraesCS1B02G308200 as a candidate gene associated with nitrogen use efficiency in wheat. Enhancing nitrogen use efficiency (NUE) in wheat production can substantially increase crop productivity while minimizing nitrogen application. In this study, QTLs for NUE-related agronomic traits were detected in two populations: (1) a natural population of 243 wheat accessions from the Yellow and Huai River Valleys in China (CH population) and (2) a recombinant inbred line (RIL) population derived from a cross between Avocet and Chilero (AC population). Nine agronomic traits were evaluated under two nitrogen regimes, namely, normal and low-nitrogen stress, at two experimental sites during two growing seasons. A total of 836 and 154 QTLs were identified through association and linkage analyses, respectively, based on the low-nitrogen tolerance index of the nine traits across all environments. By further transcriptome analysis of Chilero at the jointing, anthesis and grain-filling stages, a total of 48 differentially expressed genes were identified within the colocalization interval of the two populations. A stable QTL, QYSI1B.2 (chr1B: 501.04–508.02 Mb), was successfully validated in both populations. By examining local linkage disequilibrium, QYSI1B.2 was refined to a smaller physical region spanning 506.02–507.19 Mb. A possible candidate gene, TraesCS1B02G308200, which encodes a WRKY transcription factor, was identified through evaluation of its expression levels. These findings provide a foundation for exploring the molecular targets underlying wheat NUE.

Wheat germplasm resources are an important material foundation for genetic improvement. In this study, 170 wheat germplasm resources were used from China, the International Maize and Wheat Improvement Center (CIMMYT), Europe (France, Finland, and Sweden), the United States, Canada, and Australia. Seven nutritional quality traits were evaluated for the 2019–2020 and 2020–2021 cropping seasons. The coefficient of variability for seven nutritional quality traits ranged from 6.99% to 30.65%. The average of genetic diversity (Shannon–Wiener diversity index, H′) was 1.87. The results showed that the average frequency of high-throughput competitive allele-specific PCR (KASP) markers was 69.4% on 17 KASP markers related to seven nutritional quality traits, the average of polymorphic information content (PIC) was 0.308, and the genetic effects were from 0.01% to 18.46%. One hundred and seventy wheat germplasm resources were classified into five groups at ΔK = 5 by genetic structure analysis. The first group comprised 62 germplasm resources (36.47%), the second group included 41 germplasm resources (24.11%), the third group contained 20 germplasm resources (11.76%), the fourth group contained 20 germplasm resources (11.76%), and the fifth group had 29 germplasm resources (17.06%). Germplasm resources from CIMMYT and China were found in the first group and the second group, accounting for 56.45% and 65.85%, respectively, while European germplasm resources constituted 50% of those within the fourth group. Five favorable haplotypes were identified, which were located on chromosomes 4A, 6A, 6B, and 7A: G4A1, G4A2, G6A, G6B, and G7A. Their genetic effects were 8.71%, 8.41%, 1.00%, 18.20%, and 1.16%, respectively. In the meantime, we found 12 significant SNPs of seven nutritional quality traits using haplotype analysis. The frequency of favorable haplotypes in the population ranged from 3.53% to 62.35%. Five haplotypes, G4A1, G4A2, G6A, G6B, and G7A, were beneficial, and their genetic effects were positive. Furthermore, the results offered favorable haplotypes and germplasm resources for enhancing nutritional quality.

Background Developing novel germplasm by using wheat wild related species is an effective way to rebuild the wheat resource bank. The Psathyrostachys huashanica Keng (P. huashanica, 2n = 2x = 14, NsNs) is regarded as a superior species to improve wheat breeding because of its multi-resistance, early maturation and numerous tiller traits. Introducing genetic components of P. huashanica into the common wheat background is the most important step in achieving the effective use. Therefore, the cytogenetic characterization and influence of the introgressed P. huashanica large segment chromosomes in the wheat background is necessary to be explored. Results In this study, we characterized a novel derived line, named D88-2a, a progeny of the former characterized wheat-P. huashanica partial amphiploid line H8911 (2n = 7x = 49, AABBDDNs). Cytological identification showed that the chromosomal composition of D88-2a was 2n = 44 = 22II, indicating the addition of exogenous chromosomes. Genomic in situ hybridization demonstrated that the supernumerary chromosomes were a pair of homologues from the P. huashanica and could be stably inherited in the common wheat background. Molecular markers and 15 K SNP array indicated that the additional chromosomes were derived from the sixth homoeologous group (i.e., 6Ns) of P. huashanica. Based on the distribution of the heterozygous single-nucleotide polymorphism sites and fluorescence in situ hybridization karyotype of each chromosome, this pair of additional chromosomes was confirmed as P. huashanica 6Ns large segment chromosomes, which contained the entire short arm and the proximal centromere portion of the long arm. In terms of the agronomic traits, the addition line D88-2a exhibited enhanced stripe rust resistance, improved spike characteristics and increased protein content than its wheat parent line 7182. Conclusions The new wheat germplasm D88-2a is a novel cytogenetically stable wheat-P. huashanica 6Ns large segment addition line, and the introgressed large segment alien chromosome has positive impact on plant spikelet number and stripe rust resistance. Thus, this germplasm can be used for genetic improvement of cultivated wheat and the study of functional alien chromosome segment.

The nitrogen (N) use efficiency (NUE) in the roots of seedlings is beneficial for increasing crop yield. Creating marker-assisted selection for wheat root traits can assist wheat breeders in choosing robust roots to maximize nutrient uptake. Exploring and identifying the effect of different N supply conditions on root system architecture (RSA) is of great significance for breeding N efficient wheat varieties. In this study, a total of 243 wheat varieties native to the Yellow and Huai Valley regions of China were utilized for genome-wide association studies (GWAS). Furthermore, a recombinant inbred line (RIL) population of 123 lines derived from the cross between Avocet and Chilero was utilized for linkage examination. A hydroponic seedling experiment using a 96-well tray was conducted in the lab with two treatments: normal N (NN) and low N (LN). Five RSA traits, including the relative number of root tips (RNRT), relative total root length (RTRL), relative total root surface area (RTRS), relative total root volume (RTRV), and relative average root diameter (RARD), were investigated. GWAS and linkage analysis were performed by integrating data from the wheat 660 k single nucleotide polymorphism (SNP) chip and diversity arrays technology (DArT) to identify genetic loci associated with RSA. The results showed that, based on the ratio of RSA-related traits under two N supply conditions, a total of 497 SNP markers, which are significantly associated with RSA-related traits, were detected at 148 genetic loci by GWAS. A total of 10 QTL loci related to RSA were discovered and identified by linkage mapping. Combining two gene localization methods, three colocalized intervals were found: AX-95160997/QRtrl.haust-3D, AX-109592379/QRnrt.haust-5A, and AX-110924288/QRtrl.haust-7D/QRtrs.haust-7D. According to the physical location of the colocalization of these two sites, between 39.61 and 43.74 Mb, 649.97 and 661.55 Mb, and 592.44 and 605.36 Mb are called qRtrl-3D, qRnrt-5A, and qRtrl-7D. This study has the potential to enhance the effectiveness of selecting root traits in wheat breeding programs, offering valuable insights into the genetic underpinnings of NUE in wheat. These results could help in breeding wheat varieties with higher NUE by implementing focused breeding strategies.

Maize stalk rot reduces grain yield and quality. Information about the genetics of resistance to maize stalk rot could help breeders design effective breeding strategies for the trait. Genomic prediction may be a more effective breeding strategy for stalk-rot resistance than marker-assisted selection. We performed a genome-wide association study (GWAS) and genomic prediction of resistance in testcross hybrids of 677 inbred lines from the Tuxpeño and non-Tuxpeño heterotic pools grown in three environments and genotyped with 200,681 single-nucleotide polymorphisms (SNPs). Eighteen SNPs associated with stalk rot shared genomic regions with gene families previously associated with plant biotic and abiotic responses. More favorable SNP haplotypes traced to tropical than to temperate progenitors of the inbred lines. Incorporating genotype-by-environment (G × E) interaction increased genomic prediction accuracy.

A major stable QTL, QGPC.caas-7AL, for grain protein content of wheat, was narrowed down to a 1.82-Mb inter on chromosome 7AL, and four candidate genes were predicated. Wheat grain protein content (GPC) is important for end-use quality. Identification of genetic loci for GPC is helpful to create new varieties with good processing quality and nutrients. Zhongmai 578 (ZM578) and Jimai 22 (JM22) are two elite wheat varieties with different contents of GPC. In the present study, 262 recombinant inbred lines (RILs) derived from a cross between ZM578 and JM22 were used to map the GPC with high-density wheat Illumina iSelect 50 K single-nucleotide polymorphism (SNP) array. Seven quantitative trait loci (QTLs) were identified for GPC on chromosomes 3AS, 3AL, 3BS, 4AL, 5BS, 5DL and 7AL by inclusive composite interval mapping, designated as QGPC.caas-3AS, QGPC.caas-3AL, QGPC.caas-3BS, QGPC.caas-4AL, QGPC.caas-5BS, QGPC.caas-5DL and QGPC.caas-7AL, respectively. Among these, alleles for increasing GPC at QGPC.caas-3AS, QGPC.caas-3BS, QGPC.caas-4AL and QGPC.caas-7AL loci were contributed by ZM578, whereas those at the other three loci were from JM22. The stable QTL QGPC.caas-7AL was fine mapped to a 1.82-Mb physical interval using secondary populations from six heterozygous recombinant plants obtained by selfing a residual RIL. Four genes were predicted as candidates of QGPC.caas-7AL based on sequence polymorphism and expression patterns. The near-isogenic lines (NILs) with the favorable allele at the QGPC.caas-7AL locus increased Farinograph stability time, Extensograph extension area, extensibility and maximum resistance by 19.6

A stable genomic region conferring FSR resistance at 250 Mb on chromosome 1 was identified by GWAS. Genomic prediction has the potential to improve FSR resistance. Fusarium stalk rot (FSR) is a global destructive disease in maize; the efficiency of phenotypic selection for improving FSR resistance was low. Novel genomic tools of genome-wide association study (GWAS) and genomic prediction (GP) provide an opportunity for genetic dissection and improving FSR resistance. In this study, GWAS and GP analyses were performed on 562 tropical maize inbred lines consisting of two populations. In total, 15 SNPs significantly associated with FSR resistance were identified across two populations and the combinedPOP consisting of all 562 inbred lines, with the P-values ranging from 1.99 × 10–7 to 8.27 × 10–13, and the phenotypic variance explained (PVE) values ranging from 0.94 to 8.30

A novel QTL, TaqW-6B of water-extractable arabinoxylan content in the wheat grain on chromosome 6BL was identified and fine mapped in a narrow region 3.8 Mb. Water-extractable arabinoxylan (WE-AX), an important component of hemicellulose, is associated with various abundant health benefits. In this study, QTLs for WE-AX content were detected in two populations: (1) a recombinant inbred line (RIL) population with 164 lines derived from a cross between Avocet and Chilero (AC population) genotyped with diversity array technology (DArT), and (2) a natural population of 243 varieties (CH population) genotyped with the Axiom wheat 660 K single-nucleotide polymorphism (SNP) array. A stable QTL Qwe-ax.haust-6B, explaining 8.51–15.59

The identification of stable quantitative trait locus (QTL) for yield-related traits and tightly linked molecular markers is important for improving wheat grain yield. In the present study, six yield-related traits in a recombinant inbred line (RIL) population derived from the Zhongmai 578/Jimai 22 cross were phenotyped in five environments. The parents and 262 RILs were genotyped using the wheat 50K single nucleotide polymorphism (SNP) array. A high-density genetic map was constructed with 1 501 non-redundant bin markers, spanning 2 384.95 cM. Fifty-three QTLs for six yield-related traits were mapped on chromosomes 1D (2), 2A (9), 2B (6), 2D, 3A (2), 3B (2), 4A (5), 4D, 5B (8), 5D (2), 7A (7), 7B (3) and 7D (5), which explained 2.7-25.5% of the phenotypic variances. Among the 53 QTLs, 23 were detected in at least three environments, including seven for thousand-kernel weight (TKW), four for kernel length (KL), four for kernel width (KW), three for average grain filling rate (GFR), one for kernel number per spike (KNS) and four for plant height (PH). The stable QTLs QKl.caas-2A.1, QKl.caas-7D, QKw.caas-7D, QGfr.caas-2B.1, QGfr.caas-4A, QGfr.caas-7A and QPh. caas-2A.1 are likely to be new loci. Six QTL-rich regions on 2A, 2B, 4A, 5B, 7A and 7D, showed pleiotropic effects on various yield traits. TaSus2-2B and WAPO-A1 are potential candidate genes for the pleiotropic regions on 2B and 7A, respectively. The pleiotropic QTL on 7D for TKW, KL, KW and PH was verified in a natural population. The results of this study enrich our knowledge of the genetic basis underlying yield-related traits and provide molecular markers for high-yield wheat breeding.