Hexaploid Wheat Research Articles

Development and characterization of a novel wheat-rye T2DS·2DL-2RL translocation line with high stripe rust resistance

Rye (Secale cereale L.), a close relative of common wheat, represents a valuable genetic resource for enhancing the disease resistance of common wheat. Introducing novel rye-derived genes into wheat can potentially improve disease resistance. In this study, we successfully developed a novel wheat-rye derivative line LCR4 through hybridization between hexaploid triticale line Currency and common wheat cultivar Jimai 22 (JM22). We confirmed that LCR4 was a T2DS·2DL-2RL translocation line via comprehensive molecular cytogenetic analyses, including genomic in situ hybridization, multi-color fluorescence in situ hybridization, molecular marker analysis, and wheat SNP-arrays genotyping. Notably, upon inoculation with Puccinia striiformis f. sp. tritici (Pst) race V26 at the seedling stage and mixed Pst races at the adult stage, LCR4 exhibited robust resistance against stripe rust infection at both stages. Subsequent genetic analysis further elucidated that the translocated 2RL chromosome segment is responsible for this resistance. Consequently, LCR4 harboring elite agronomic traits can be effectively employed in breeding programs against stripe rust.

Application of univariate, multivariate, and mixed models to the stability analysis of Ethiopian tetraploid wheat cultivars under irrigation condition

AbstractThe testing of durum wheat (Triticum turgidum subsp. durum) varieties in different irrigated environments is critical for determining the stability of their performance and adaptation. In this study, 12 popular and newly developed durum wheat varieties were examined in eight irrigated locations with the purpose of investigating genotype–environment interaction and their effect on Ethiopian tetraploid wheat yield stability across diverse environments. The field experiment has two replications with a randomized complete block design. Multivariate (analysis of variance, additive main effect and multiplicative interaction [AMMI], and genetics, genetics × environment [GGE] biplot) and univariate (bi [regression coefficient], S2d [deviation from regression], σi2 [Shukla's stability variance], Wi2 [Wricke's ecovalence], YSi [yield stability statistic], and CVi [coefficient of variance]) analysis methods were used to identify stable varieties. The AMMI analysis showed that the genetic × environmental interaction was highly significant (p > 0.01), while the genotype and environment variation were not significant. The first two principal component axes (IPCA1 and IPCA2) were highly significant (p > 0.01) and contributed 79% of the total GE interaction. Univariate statistical models indicate that Bulala is a stable, high‐yielding variety that can adapt to various environments. GGE biplot analysis revealed that the eight test environments were clustered into three mega‐environments, ranked Bulala as the most stable variety across diverse environments. The results of the combined mean analysis, multivariate and univariate models revealed that Bulala is a high yielder (3.46 tons ha−1) and stable variety across all test environments, while Mukiye variety has a high yield (3.43 tons ha−1) but is not as stable or adaptive to multiple locations. As a result, Bulala was recommended for further demonstration and popularization in test locations and places with similar agroecologies under irrigation.

Efficient gene disruption in polyploid genome by Cas9-Trex2 fusion protein.

The fusion of the exonuclease Trex2 with the Cas9 protein significantly enhanced the efficiency of genome editing in hexaploid common wheat, particularly for the simultaneous editing of multiple favorable alleles within a single generation, thereby facilitating genome editing-assisted breeding in polyploid crops.

Natural alleles of LEAFY and WAPO1 interact to regulate spikelet number per spike in wheat

Key messageSpecific combinations ofLFY andWAPO1 natural alleles maximize spikelet number per spike in wheat. Spikelet number per spike (SNS) is an important yield component in wheat that determines the maximum number of grains that can be formed in a wheat spike. In wheat, loss-of-function mutations in LEAFY (LFY) or its interacting protein WHEAT ORTHOLOG OF APO1 (WAPO1) significantly reduce SNS by reducing the rate of formation of spikelet meristems. In previous studies, we identified a natural amino acid change in WAPO1 (C47F) that significantly increases SNS in hexaploid wheat. In this study, we searched for natural variants in LFY that were associated with differences in SNS and detected significant effects in the LFY-B region in a nested association mapping population. We generated a large mapping population and confirmed that the LFY-B polymorphism R80S is linked with the differences in SNS, suggesting that LFY-B is the likely causal gene. A haplotype analysis revealed two amino acid changes P34L and R80S, which were both enriched during wheat domestication and breeding suggesting positive selection. We also explored the interactions between the LFY and WAPO1 natural variants for SNS using biparental populations and identified significant interaction, in which the positive effect of the 80S and 34L alleles from LFY-B was only detected in the WAPO-A1 47F background but not in the 47C background. Based on these results, we propose that the allele combination WAPO-A1-47F/LFY-B 34L 80S can be used in wheat breeding programs to maximize SNS and increase grain yield potential in wheat.

Knockout mutation in TaD27 enhances number of productive tillers in hexaploid wheat.

Recent advances allow the deployment of cluster regularly interspaced short palindromic repeats (CRISPR)-associated endonucleases (Cas) system for the targeted mutagenesis in the genome with accuracy and precision for trait improvement in crops. CRISPR-Cas systems have been extensively utilized to induce knockout or frameshift mutations in the targeted sequence of mostly negative regulating genes for wheat improvement. However, most of the reported work has been done in non-commercial varieties of wheat and introgression of edited alleles into breeding population comes with the penalty of unwanted linkage-drag. Wheat yield is controlled by various genes such as positive and negative regulators. The TaD27 gene is described as a negative regulator of shoot branching or tillering and involved in the biosynthesis of strigolactones. In this study, we developed Tad27 knockout mutant lines of an elite wheat cultivar that showed a twofold increase in the number of tillers and 1.8-fold increase in the number of grains per plant. Subsequently, enhancing the grain yield without any morphological penalty in the architecture of the plants. The co-transformation of regeneration enhancing growth regulator, Growth Regulating Factor 4 (GRF4) and its cofactor GRF-Interacting Factor 1 (GIF1), under single T-DNA cassette improved the regeneration efficiency up to 6% of transgenic events from mature embryos of wheat. Our results indicate that the CRISPR-mediated targeted mutagenesis confers the potential to knockout yield-related negative regulators in elite cultivars of wheat that can substantially enhance grain yield per plant and this strategy can be harnessed for the improvement of future wheat.

Triticum monococcum subsp. monococcum and aegilopoides: new sources of resistance to the dipteran pest, Hessian fly (Diptera: Cecidomyiidae).

The Hessian fly, Mayetiola destructor (Say) belonging to the order Diptera (family: Cecidomyiidae), is a destructive pest of host wheat (Triticum aestivum L.) causing significant economic losses. Although planting resistant wheat cultivars harboring an effective Hessian fly resistance gene (H) is the most economical and environmentally friendly pest management strategy, it imposes selection pressure on the insect populations and can lead to the evolution of Hessian fly virulence. This results in the eventual failure of the deployed H gene. New sources and novel types of resistance are urgently needed to expand the repertoire of H genes and enable strategies that are more effective and durable over the long-term. New sources of Hessian fly resistance have been identified from tetraploid (T. turgidum L., AABB) and hexaploid (T. aestivum, AABBDD) wheat species, as well as from wheat's D-genome donor (Aegilops tauschii Coss., DD). In contrast, diploid einkorn wheat (T. monococcum L., AA) has not been extensively explored for Hessian fly resistance. In this study, we phenotyped 506 T. monococcum accessions belonging to 2 subspecies, T. monococcum L. subsp. monococcum (205 accessions) and T. monococcum subsp. aegilopoides (Link) Thell. (301 accessions), for resistance against 2 predominant Hessian fly biotypes, L and GP (Great Plains). Three and 6 accessions belonging to subsp. monococcum and aegilopoides, respectively, showed > 70% resistance. These accessions provide additional resources for improving wheat cultivars as mitigating strategies for Hessian fly management.

Novel insight into the cross-linking of typical wheat starch-based food components during freeze-drying: Starch, lipids, proteins and their ternary mixtures

Starch-based foods have a large consumer base worldwide. It is known that the quality of freeze-dried starch-based products is subject to deterioration during the production process. The present study was unprecedented carried out to examine the effects of freeze-drying on the cross-linking between components of gelatinized starch-based system. The results showed that the retrogradation of starch in the process of dehydration, the weakening of the binding capacity between the substrate and water of the freeze-dried product and the weakening of the interaction strength between the components of the product were the key mechanisms leading to the quality deterioration of the wheat starch-based conditioned food during the freeze-drying. The addition of lipid and protein can inhibit starch retrogradation during freeze-drying, and the inhibition effect of oil is better. However, the intervention of oil and fat will cause dehydrated starch to re-adsorb the melted oil/water mixture during the freeze-drying process, resulting in the deterioration of product quality. The intervention of protein will improve the binding ability of freeze-dried wheat starch-based product matrix to water. In the ternary system, the intervention of protein will weaken the inhibition effect of lipid on retrogradation of starch in the freeze-drying process. In addition, the lower drying temperature will lead to the decrease of the interaction strength between the components of ternary mixed system. Avoiding the melting of frozen materials during drying is the key control point to improve the quality of freeze-dried wheat starch-based products.

Genetic Transformation of Triticum dicoccum and Triticum aestivum with Genes of Jasmonate Biosynthesis Pathway Affects Growth and Productivity Characteristics.

The transformation protocol based on the dual selection approach (fluorescent protein and herbicide resistance) has been applied here to produce transgenic plants of two cereal species, emmer wheat and bread wheat, with the goal of activating the synthesis of the stress hormone jasmonates by overexpressing ALLENE OXIDE SYNTHASE from Arabidopsis thaliana (AtAOS) and bread wheat (TaAOS) and OXOPHYTODIENOATE REDUCTASE 3 from A. thaliana (AtOPR3) under the strong constitutive promoter (ZmUbi1), either individually or both genes simultaneously. The delivery of the expression cassette encoding AOS was found to affect morphogenesis in both wheat species negatively. The effect of transgene expression on the accumulation of individual jasmonates in hexaploid and tetraploid wheat was observed. Among the introduced genes, overexpression of TaAOS was the most successful in increasing stress-inducible phytohormone levels in transgenic plants, resulting in higher accumulations of JA and JA-Ile in emmer wheat and 12-OPDA in bread wheat. In general, overexpression of AOS, alone or together with AtOPR3, negatively affected leaf lamina length and grain numbers per spike in both wheat species. Double (AtAOS + AtOPR3) transgenic wheat plants were characterized by significantly reduced plant height and seed numbers, especially in emmer wheat, where several primary plants failed to produce seeds.

The association of glutenin subunit composition to baking quality traits of spring and winter wheat in Estonia

In Estonian local mills, protein content (PC) and wet gluten content (WGC) are among the main indicators considered and evaluated when purchasing grains. Protein composition also significantly affects baking quality. The baking quality of ten winter wheat (WW) and spring wheat (SW) varieties was studied at the Center of Estonian Rural Research and Knowledge (METK). PC, WGC, gluten index (GI), and dough stability time (DST) were higher in SW varieties. PC was positively correlated with WGC and loaf volume (LV) in both wheat types. PC and WGC were negatively correlated with GI and positively correlated with DST only in WW. The viscoelastic properties of dough are linked to its high- and low molecular weight glutenin subunits (HMW-GS and LMW-GS). The allelic composition of the glutenin genes was determined using DNA markers. All the studied varieties had the allele Glu-D1d and additional allele Glu-D1a was found in the variety ‘Voore’. Fourteen varieties had Glu-A1a and b alleles associated with improved backing quality. Alleles Glu-B1с and Glu-B1b were found in WW varieties. SW varieties carried alleles Glu-B1al, b, с and h. The average QS was higher in SW. Eight varieties had null alleles Glu-A1c, Glu-A3e, and Glu-B3j, which negatively affected bread-making quality.

Evaluation of the Spike Diversity of Seven Hexaploid Wheat Species and an Artificial Amphidiploid Using a Quadrangle Model Obtained from 2D Images

The spike shape and morphometric characteristics are among the key characteristics of cultivated cereals, being associated with their productivity. These traits are often used for the plant taxonomy and authenticity of hexaploid wheat species. Manual measurement of spike characteristics is tedious and not precise. Recently, the authors of this study developed a method for wheat spike morphometry utilizing 2D image analysis. Here, this method is applied to study variations in spike size and shape for 190 plants of seven hexaploid (2n = 6x = 42) species and one artificial amphidiploid of wheat. Five manually estimated spike traits and 26 traits obtained from digital image analysis were analyzed. Image-based traits describe the characteristics of the base, center and apex of the spike and common parameters (circularity, roundness, perimeter, etc.). Estimates of similar traits by manual measurement and image analysis were shown to be highly correlated, suggesting the practical importance of digital spike phenotyping. The utility of spike traits for classification into types (spelt, normal and compact) and species or amphidiploid is shown. It is also demonstrated that the estimates obtained made it possible to identify the spike characteristics differing significantly between species or between accessions within the same species. The present work suggests the usefulness of wheat spike shape analysis using an approach based on characteristics obtained by digital image analysis.

Analysis of wheat traits that determine female farmers’ preferences for wheat varieties: Gender insight from southern tigray, ethiopia

BackgroundWheat productivity has been constrained by changing agroecological and socio-economic conditions, coupled with a lower uptake of new farm technologies. Gender difference is one major social category that needs systematic estimation to distinguish the adoption of technology and the preference between male and female farmers. Hence, this study analyzes wheat traits that determine female farmers’ preferences for wheat varieties in southern Tigray, Ethiopia.MethodsThe primary data was collected by using semi-structured interviews, focus group discussions, and key informant interviews from 169 female farmers who were selected by using a two-stage sampling procedure. This study used descriptive statistics and a multinomial logit model to estimate the wheat traits that determine the wheat variety preference of female farmers.ResultThe result obtained from descriptive statistics shows the existence of heterogeneity in trait preference of female farmers among bread wheat, durum wheat, and local wheat variety types. The result indicates that risk-averting traits were the most frequently selected traits for both wheat types. Furthermore, the result of multinomial logit model indicates that wheat variety traits such as yield difference, marketability, resistance to drought, and resistance to frost and disease significantly influenced female farmers’ choice of wheat variety to grow.ConclusionThis study aims to fill the current knowledge gaps and tackle the significant issues faced by wheat-growing female farmers by examining the wheat traits that influence the wheat variety choice of these farmers. The finding scrutinized that even though the female farmers’ choices of wheat variety traits were heterogeneous, the majority of their decisions on the choice of wheat variety were primarily guided by risk-averting and yield traits. This evidence provides significant insight for developing gender-sensitive variety traits in crop breeding programs. Moreover, the findings significantly help policymakers, input suppliers, breeding programs, and extension workers to become more gender-responsive, to increase the productivity of wheat-growing female farmers.

Tracing post-domestication historical events and screening pre-breeding germplasm from large gene pools in wheat in the absence of phenotype data.

Wheat, particularly common wheat (Triticum aestivum L.), is a major crop accounting for 25% of the world cereal production and thriving indiverse ecogeographic regions. Its adaptation to diverse environments arises from its three distinct genomes adapted to different environments and post-domestication anthropogenic interventions. In search of key genomic regions revealing historic events and breeding significance to common wheat, we performed genome scan and genome-environment association (GEA) analyses using high-marker density genotype datasets. Whole-genome scans revealed highly differentiated regions on chromosomes 2A, 3B, and 4A. In-depth analyses corroborated our previous prediction of the 4A differentiated region signifying the separation between Spelt/Macha and other wheat types. Individual chromosome scans captured key introgressions, includingone from T. timopheevii and one fromThinopyrum ponticum on 2B and 3D, respectively, as well as known genes such as Vrn-A1 on 5A. GEA highlighted loci linked to latitude-induced environmental variations, influencing traits such as photoperiodism and responses to abiotic stress. Variation at theVrn-A1 locus on 5A assigned accessions to two haplotypes (6% and 94%). Further analysis on Vrn-A1 coding gene revealed four subgroups of the major haplotype, while the minor haplotype remained undifferentiated. Analyses at differentiated loci mostly dichotomized the population, illustrating the possibility of isolating pre-breeding materials with desirable traits from large gene pools in the absence of phenotype data. Given the current availability of broad genetic data, the genome-scan-GEA hybrid can be anefficient and cost-effective approach for pinpointing environmentally resilient pre-breeding germplasm from vast gene pools, including gene banks regardless of trait characterization.

Effect of the Presence of Physiological Disorder Recognized as “yellow berry” on the Quality of Starch in Bread Wheat (Triticum aestivum) and Durum Wheat (Triticum durum)

AbstractGenetic and environmental factors influence wheat grain quality, including vitreousness, protein, and starch content. Yellow berry (YB), a physiological condition, adversely affects wheat quality, particularly in irrigated fields with limited nitrogen application, leading to starch‐rich, low‐protein grains. This study examines common wheat, used in baking industries, and durum wheat, primarily employs for pasta production. The focus is on investigating how the physicochemical properties of these wheat types change with the presence of YB, that impacts protein content negatively, increasing total starch content. Fourier‐transform infrared spectroscopy reveals structural changes in YB‐affected grains, while X‐ray diffraction indicates varying crystallinity. In determination of amylose, an increase of 6% in bread wheat with YB and 3% in durum wheat with YB is observed. In the case of RVA (Rapid Visco Analyzer) analysis, a notable increase in viscosity is evident in the treatments that included the yellow berry. This finding suggests that YB is associated with substantial modifications in starch properties, such as amylose‐to‐amylopectin ratio, chain length, and degree of branching, among several other components, which may have important implications for the texture and quality of food products. This study calls for further research to mitigate YB's impact and enhances the quality of wheat‐derived foods.

Study of Ancient and Modern Wheat Grain Textures, Physiochemical Properties, and Biscuit Quality

We conducted a comprehensive study to investigate how different types of wheat affect the quality of biscuits. Our research included an ancient wheat variety called T. spherococcum, as well as present-day cultivated hard wheat varieties and soft wheat varieties (T. aestivum). We compared three hard wheat varieties (MACS6478, MACS2496, NI5439) and two soft wheat varieties (HS 490, NIAW3170) with ancient wheat (T. spherococcum) to analyze various aspects such as agronomic, grain and flour physicochemical, dough mixing, and biscuit quality parameters. Our results showed that soft wheat has a weaker association between starch and the protein matrix in the grain, leading to less starch damage, a lower particle size index (PSI), and higher flour recovery than hard wheat. Soft wheat flour also has lower gluten strength, a higher gliadin fraction, and decreased mixing resistance. Additionally, soft wheat flour has lower starch damage, which results in lower alkaline water retention capacity (AWRC) than hard wheat flour. These physiochemical findings helped us better understand how these traits related to biscuit quality. The study concluded that simple and fast physiochemical tests such as PSI, MST, AWRC, and flour protein content would help to select the best biscuit-quality wheat. These tests are quick and simple and do not need high-end sophisticated instruments. We also concluded that T. spherococcum was a hard wheat, and its flour physicochemical dough mixing properties were similar to that of hard wheat. It also produced inferior quality biscuits like hard wheat.

Deciphering the differences of bacterial communities between high- and low-productive wheat fields using high-throughput sequencing.

Microbial communities have been demonstrated to be essential for healthy and productive soil ecosystems. However, an understanding of the relationship between soil microbial community and soil productivity levels is remarkably limited. In this study, bulk soil (BS), rhizosphere soil (RS), and root (R) samples from the historical high-productive (H) and low-productive (L) soil types of wheat in Hebei province of China were collected and analyzed by high-throughput sequencing. The study highlighted the richness, diversity, and structure of bacterial communities, along with the correlation networks among different bacterial genera. Significant differences in the bacterial community structure between samples of different soil types were observed. Compared with the low-productive soil type, the bacterial communities of samples from the high-productive soil type possessed high species richness, low species diversity, complex and stable networks, and a higher relative abundance of beneficial microbes, such as Pseudoxanthomonas, unclassified Vicinamibacteraceae, Lysobacter, Massilia, Pseudomonas, and Bacillus. Further analysis indicated that the differences were mainly driven by soil organic matter (SOM), available nitrogen (AN), and electrical conductivity (EC). Overall, the soil bacterial community is an important factor affecting soil health and crop production, which provides a theoretical basis for the targeted regulation of microbes in low-productivity soil types.

Transcriptomic response to nitrogen availability reveals signatures of adaptive plasticity during tetraploid wheat domestication.

The domestication of crops, coupled with agroecosystem development, is associated with major environmental changes and provides an ideal model of phenotypic plasticity. Here, we examined 32 genotypes of three tetraploid wheat (Triticum turgidum L.) subspecies, wild emmer, emmer, and durum wheat, which are representative of the key stages in the domestication of tetraploid wheat. We developed a pipeline that integrates RNA-Seq data and population genomics to assess gene expression plasticity and identify selection signatures under diverse nitrogen availability conditions. Our analysis revealed differing gene expression responses to nitrogen availability across primary (wild emmer to emmer) and secondary (emmer to durum wheat) domestication. Notably, nitrogen triggered the expression of twice as many genes in durum wheat compared to that in emmer and wild emmer. Unique selection signatures were identified at each stage: primary domestication mainly influenced genes related to biotic interactions, whereas secondary domestication affected genes related to amino acid metabolism, in particular lysine. Selection signatures were found in differentially expressed genes (DEGs), notably those associated with nitrogen metabolism, such as the gene encoding glutamate dehydrogenase (GDH). Overall, our study highlights the pivotal role of nitrogen availability in the domestication and adaptive responses of a major food crop, with varying effects across different traits and growth conditions.

On the evolution and genetic diversity of the bread wheat D genome

Bread wheat (Triticum aestivum) became a globally dominant crop after incorporating the D genome from the donor species Aegilops tauschii, but the evolutionary history that shaped the D genome during this process remains to be clarified. Here, we propose a renewed evolutionary model linking Ae. tauschii and the hexaploid wheat D genome by constructing an ancestral haplotype map covering 762 Ae. tauschii and hexaploid wheat accessions. We dissect the evolutionary trajectories of Ae. tauschii lineages and report a few independent intermediate accessions, demonstrating that low to frequent inter-sublineage gene flow has enriched the diversity of Ae. tauschii. We discovered that the D genome of hexaploid wheat was inherited from a unified ancestral template, but with a mosaic composition that was highly mixed and derived mainly from three Ae. tauschii L2 sublineages located in the Caspian coastal region. This result suggests that early agricultural activities facilitated innovations in D-genome composition and finalized the success of hexaploidization. We found that the majority (51.4%) of genetic diversity was attributed to novel mutations absent in Ae. tauschii, and we identified large Ae. tauschii introgressions from various lineages, which expanded the diversity of the wheat D genome and introduced beneficial alleles. This work sheds light on the process of wheat hexaploidization and highlights the evolutionary significance of the multi-layered genetic diversity of the bread wheat D genome.

Optimisation of quality features of new wheat beers fermented through sequential inoculation of non-Saccharomyces and Saccharomyces yeasts

The choice of the starchy ingredients as well as that of the yeasts strongly can represent a useful tool to differentiate the final beers. Our research investigated twelve white beers obtained applying a 2-factor mixed 3-level/4-level experimental design. The first factor was the cereal mixture, with 3 combinations of barley malt (65 %) and unmalted wheat (35 % of common, durum, or emmer). The second factor was the yeast used to carry out the fermentation trials, i.e.: a S. cerevisiae starter strain (WB06); an oenological S. cerevisiae strain (9502); two mixed starters made of an oenological Schizosaccharomyces pombe strain (6956) and, alternatively, one of the two S. cerevisiae strains. Most beer attributes were significantly (p < 0.05) influenced by the two considered factors with the following exceptions: the wheat species did not affect maltotriose, maltose, pH, total and volatile acidity, floral flavour, and sweetness; the yeast did not exert significant effects on foam colour, turbidity, overall olfactory intensity, yeast flavour, and body. The flavour of fruits and aromatic herbs were not influenced by the factors studied. Alcohol content was maximised using the unmalted durum wheat (∼7 %) and S. cerevisiae WB06 (∼6.8 %). The beer antioxidant content was increased by the use of emmer (566 mg/L) and by the application of the mixed inoculum (478–487 mg/L). The beers made with unmalted common wheat and fermented by the S. cerevisiae strains alone obtained the best overall sensory score (3.7). As shown by the Principal Component Analysis, the beers were better classified by the type of unmalted wheat than by the fermenting yeast. A multiple regression analysis was performed by fitting the analytical parameters that highlighted significant differences among the beers to a second-order polynomial model. Data concerning colour, glycerol concentration, FC-TPC, and antioxidant activity were satisfactorily predicted (R2 > 0.8) by the fitted models.

Rmg10, a Novel Wheat Blast Resistance Gene Derived from Aegilops tauschii.

Wheat blast, caused by Pyricularia oryzae (syn. Magnaporthe oryzae) pathotype Triticum (MoT), is a devastating disease that can result in up to 100% yield loss in affected fields. To find new resistance genes against wheat blast, we screened 199 accessions of Aegilops tauschii, the D genome progenitor of common wheat (Triticum aestivum), by seedling inoculation assays with Brazilian MoT isolate Br48 and found 14 resistant accessions. A synthetic hexaploid wheat line (Ldn/KU-2097) derived from a cross between the T. turgidum 'Langdon' (Ldn) and resistant A. tauschii accession KU-2097 exhibited resistance in seedlings and spikes against Br48. In an F2 population derived from 'Chinese Spring' × Ldn/KU-2097, resistant and susceptible individuals segregated in a 3:1 ratio, suggesting that the resistance from KU-2097 is controlled by a single dominant gene. We designated this gene Rmg10. Genetic mapping using an F2:3 population from the same cross mapped the RMG10 locus to the short arm of chromosome 2D. Rmg10 was ineffective against Bangladesh isolates but effective against Brazilian isolates. Field tests in Bolivia showed increased spike resistance in a synthetic octaploid wheat line produced from a cross between common wheat cultivar 'Gladius' and KU-2097. These results suggest that Rmg10 would be beneficial in farmers' fields in South America.

Impacts of Whole-Grain Soft Red, Whole-Grain Soft White, and Refined Soft White Wheat Flour Crackers on Gastrointestinal Inflammation and the Gut Microbiota of Adult Humans.

Consumption of whole-grain wheat has been associated with positive health outcomes, but it remains unclear whether different types of wheat elicit varying effects on the gut microbiome and intestinal inflammation. The objectives of this research were to investigate the effect of two whole-grain wheat flours versus refined wheat flour on the diversity of the human gut microbiota, as well as on butyrate production capacity and gastrointestinal inflammation, using one-week dietary interventions. For this study, 28 participants were recruited, with ages ranging from 18 to 55 years and a mean BMI of 26.0 kg/m2. For four weeks, participants were provided 80 g daily servings of different wheat crackers: Week A was a run-in period of crackers made from soft white wheat flour, Week B crackers were whole-grain soft white wheat flour, Week C crackers were a wash-out period identical to Week A, and Week D crackers were whole-grain soft red wheat flour. At the end of each week, participants provided fecal samples that were analyzed for markers of intestinal inflammation, including lipocalin and calprotectin, using enzyme-linked immunosorbent assays and quantitative real-time PCR. The primary outcome, gut bacterial community alpha and beta diversity, was similar across timepoints. Three taxa significantly differed in abundance following both whole-grain wheat flour interventions: Escherichia/Shigella and Acidaminococcus were significantly depleted, and Lachnospiraceae NK4A136 group was enriched. Secondary outcomes determined that protein markers of intestinal inflammation and genes related to putative butyrate production capacity were similar throughout the study period, with no significant changes. Lipocalin concentrations ranged from 14.8 to 22.6 ng/mL while calprotectin ranged from 33.2 to 62.5 ng/mL across all 4 weeks. The addition of wheat crackers to the adult human subjects' usual diet had a minimal impact on their gastrointestinal inflammation or the gut microbiota.