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The resistance gene Lr34 conditions durable disease resistance to many biotrophic wheat pathogens and has been incorporated into many wheat cultivars throughout the world. Lr67 is a similar adult plant resistance gene that also conditions resistance to multiple wheat diseases. Both genes significantly reduce disease severity and work in an additive manner with other rust resistance genes. To determine the effect of Lr34 and Lr67 on Fusarium head blight (FHB), two doubled haploid populations, segregating for each of these genes, were developed in the Thatcher wheat background by crossing near‐isogenic lines. Progeny from these populations were tested in five Fusarium graminearum‐inoculated disease nurseries and assessed for FHB symptoms, using a visual rating index (VRI), and deoxynivalenol (DON) accumulation. Both Lr34 and Lr67 significantly reduced visual symptoms of FHB and DON overall, though those effects were not significant in all environments. The overall reduction in the group of progeny with the resistant allele compared to the group with the susceptible allele for VRI was 9.4% for Lr34 and 6.8% for Lr67, while for DON it was 16.4% for Lr34 and 14.9% for Lr67. These genes represent important tools for improving resistance to FHB and many other diseases in wheat. [ABSTRACT FROM AUTHOR]

Zinc (Zn) fertilization of hard red and soft white winter wheat (Triticum aestivum L.) is uncommon in the low precipitation zone of the inland Pacific Northwest. It is uncommon because there have been no indications of deficiency. Soil test data, however, show Zn levels have been declining over time. We conducted a four‐site‐year experiment to evaluate effects of fertilization on early‐season tissue Zn concentration (TZC), dry matter accumulation (DMA), Zn uptake (ZNU), the grain test weight (TWT), protein content (PRO), and yield (YLD) of two regionally adapted cultivars. Planting occurred late in September or early in October. Zinc fertilizer, placed with the seed while planting, was applied at rates of 0 and 5 kg Zn ha−1. Application of 5 kg Zn ha−1 increased TZC and ZNU at one of two sites. There were corresponding trends of increased DMA and improved YLD. Response to fertilization occurred on a relatively shallow soil that had a diethylenetriamine‐pentaacidic acid–extractable Zn test level of 0.3 mg kg−1. Core Ideas: Zinc fertilization increased tissue Zn concentration and Zn uptake in winter wheat (Triticum aestivum L.) at one of two experimental sites.There were corresponding treatment‐induced trends of increased dry matter accumulation and improved grain yield.Response to fertilization occurred on a relatively shallow soil that had a diethylenetriamine‐pentaacidic acid‐extractable soil test Zn level of 0.3 mg kg−1.Response to fertilization may have been due, at least in part, to the near‐surface position of carbonates and alkalinity. [ABSTRACT FROM AUTHOR]

BACKGROUND: The continuous cultivation of rice–wheat in the same field is a key element of double‐cropping systems in the Indo‐Gangetic plains. Yields of such cropping systems are increasingly challenged as climate change drives increases in temperature, terminal stress and uneven rainfall, delaying rice harvesting and subsequently delaying sowing of wheat. In this paper, we evaluate the optimum sowing dates to achieve high grain yield and quality of wheat cultivars in northwest India. Three cultivars of wheat, HD‐2967, HD‐3086 and PBW‐723, were sown on three different dates at the research farm of ICAR‐IARI, New Delhi, to generate different weather conditions at different phenological stages. Different biophysical attributes, photosynthetic rate, stomatal conductance and transpiration rate, were measured at different phenological stages. Yield and grain quality parameters such as protein, starch, amylopectin, amylose and gluten were measured in different cultivars sown on different dates. RESULTS: Biophysical parameters were found to be higher in timely sown crops followed by late‐sown and very late‐sown crops. Further, the different sowing dates had a significant (P < 0.05) impact on the grain quality parameters such as protein, starch, amylopectin, amylose and gluten content. Percentage increases in the value of starch and amylose content under timely sown were ~7% and 11.6%, ~5% and 8.4%, compared to the very late‐sown treatment. In contrast, protein and amylopectin contents were found to increase by ~9.7% and 7.5%, ~13.8% and 16.6% under very late‐sown treatment. CONCLUSION: High‐temperature stress during the grain‐filling periods significantly decreased the grain yield. Reduction in the grain yield was associated with a reduction in starch and amylose content in the grains. The protein content in the grains is less affected by terminal heat stress. Cultivar HD‐3086 had higher growth, yield as well as quality parameters, compared to HD‐2967 and PBW‐723 in all treatments, hence could be adopted by farmers in northwest India. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A simulation study was conducted for assessing the climate change impact on wheat cultivars (HD2967 and PBW725) under RCP 4.5 and RCP 6.0 scenarios for four agroclimatic zones (AZ) of Punjab. The yield trend during 70 years (2025–95) using the CERES‐Wheat model was assessed for different sowing windows (end October to end November). The maximum/minimum temperature and rainfall, respectively, during the season varied between 25–27°C/9–12°C and 27–103 mm (AZ II), 24–27°C/8–13°C and 37–105 mm (AZ III), 24–26°C/9–12°C and 20–80 mm (AZ IV) and 23–26°C/9–12°C and 30–71 mm (AZ V). The climatic conditions largely vary across the state, because of which only AZs II, III and V were found productive for wheat crop with most of the years lying in the high yield (>5000 kg/ha) category. The sowing of HD2967 during mid to end November would be suitable adaptation strategy for wheat growers in the state. [ABSTRACT FROM AUTHOR]

Cultivar resistance is a major asset for the management of crop diseases and can play an important role in agroecological transition. However, the wide deployment of a reduced number of resistance genes can lead to a rapid adaptation of pathogen populations and to a loss of resistance efficiency. The objective of this study was to characterize and discuss different trajectories of adult plant ratings for resistance to yellow rust in French wheat cultivars between 1963 and 2018. Among 719 cultivars assessed for at least 2 years, 590 cultivars showed no variation in their resistance scores, despite a mean of 4.3 years and up to 33 years of assessment. A set of descriptive variables was computed in order to compare the evolution of resistance score of 129 cultivars that experienced resistance variation. We applied a principal component analysis and a hierarchical clustering on principal components to this subdataset to constitute clusters corresponding to different cultivar profiles. Clusters C1 and C2 had small resistance variations (1–2 points on a 1–9 scale); Cluster C3 had long assessment durations and several small drops in resistance score and could be associated with quantitative resistance erosion; Cluster C4 included major drops in resistance score (4–5 points), often associated with known breakdowns of major resistance genes. Cases of limited drops in resistance score as a known resistance gene was broken down suggest the presence of efficient adult plant resistance. We discuss the use of information extracted from this dataset and methods to further explore sources of resistance to yellow rust present in French cultivars. [ABSTRACT FROM AUTHOR]

Seeding rate recommendations for wheat (Triticum aestivum L.) are often 150–450 seeds m−2. However, we hypothesize that wheat grown with high resource availability (i.e., fertility and moisture) can maximize yield under considerably lower rates. Our objectives were to explore winter wheat response to low populations under high resource availability using yield‐contest fields as a case study. A factorial experiment evaluated four wheat varieties (i.e., Joe, WB‐Grainfield, Langin, and LCS Revere) exposed to five seeding rates (50, 100, 150, 200, and 250 seeds m−2) during five seasons in commercial wheat fields managed by yield‐contest winning producers near Leoti, KS. Fields were silt‐loam soils with high available water‐holding capacity, long‐term history of manure application with non‐limiting fertility, and adopted a sorghum [Sorghum bicolor (L.) Moench]–fallow–wheat rotation. Plant density ranged from 26 to 341 plants m−2 and yield ranged from 3.2 to 6.8 Mg ha−1. Water use efficiency of 19.5 kg ha−1 mm−1 suggested no management limitations to yield. Quadratic models portrayed the grain yield–plant density relation well, with 95% of the maximum yield reached at 68 to 91 plants m−2 for crops sown at the optimum date (4 out of 5 years), and at 312 plants m−2 for a late‐sown crop. Greater fall temperature accumulation reduced the relative yield between the maximum and minimum seeding rates. There was no variety × plant density interaction and Langin was the most consistent yielding variety across environments. Optimum plant density for winter wheat in environments with high resource availability may be considerably lower than current recommendations. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) has inflorescences made up of multiple spikelets arranged along a central rachis, with each spikelet producing between one and four grains. The Grain Number Increase 1 (GNI‐A1) gene wheat directly influences grain number per spikelet and grain size. Three naturally occurring alleles have been described previously: GNI‐A1‐105N, 105Y, and 105K. This project's goal was to characterize the impact of these alleles within hard red spring wheat cultivars in Montana, where each of the alleles is common. The 105N allele and the 105K allele were compared through analysis of an F5 Vida by Spring‐Yellowstone recombinant inbred line (RIL) population, and with near isogenic lines (NILs) derived from the same population. The 105N allele and the 105Y allele were compared with NILs derived from an F4 Lanning by Egan RIL population. We analyzed the impact of each of the three alleles and compared their effects on inflorescence architecture, grain size, grain yield, grain quality, and milling quality under Bozeman, MT, field conditions. Data show that either loss‐of‐function alleles (105Y and 105K) increased grain number per spikelet by 5% when compared to the more functional allele (105N) across all years and environments tested. Overall grain size was not significantly reduced and there was also not a significant increase in overall grain yield. Core Ideas: The wheat Grain Number Increase 1 gene increases grain number per spikelet.Grain Number Increase 1 missense alleles increased grain number per inflorescence by 5%.Grain Number Increase 1 missense alleles did not increase grain yield. [ABSTRACT FROM AUTHOR]

Crop models are valuable tools for simulating and assessing genotype‐by‐environment interactions. In most studies, these models are parameterized based on crop data from a few sites and years, which often limits their applicability to a broader geographic context. Therefore, we utilize countrywide multi‐environment variety trial data in this study to implement a genotype‐specific model parameterization for winter rye (Secale cereale L.) in Germany. We use the Crop and Environment REsource Synthesis (CERES) model originally used for wheat available in the decision support system for agrotechnology transfer (DSSAT) framework and adapt and evaluate it for rye. Calibration and evaluation involved a comprehensive agronomic trial datasets for the rye cultivar Palazzo, encompassing 194 site‐years of experiments covering various cereal production regions in Germany. The parameterization followed a structured approach, encompassing phenology, growth, and yield‐specific coefficients. The parameterized CSM‐CERES‐Rye (where CSM is cropping system model) demonstrated reasonable accuracy in simulating critical crop parameters, including aboveground biomass, leaf area index, tiller, grain number, unit seed weight, and grain yield. The model is available for diverse model‐based assessments of rye cultivation, including evaluating crop management, analyzing crop rotations, and assessing rye's suitability across varied environments, making it valuable for sustainable agriculture and decision‐making. Core Ideas: Adapting DSSAT‐CSM‐CERES‐Wheat (where DSSAT is decision support system for agrotechnology transfer, CSM is cropping system model, and CERES is crop and environment resource synthesis) for cereal rye using comprehensive data from German plant variety trials for the first time.A structured sequential method was employed for model parameterization.The model enables essential analyses, including crop management, rotations, and suitability assessments. [ABSTRACT FROM AUTHOR]

The effects of the seed gall nematode 'Anguina tritici' (Steinbuch, 1799) on the agronomic characteristics of some bread wheat cultivars were investigated at the Trakya Agricultural Research Institute, Türkiye. An experiment was carried out in two different locations in Edirne in the 2019–2020 growing season. A total of 19 winter bread wheat cultivars were evaluated to assess infected grain number, healthy grain number, infected grain rate and yield. According to the results of the combined variance analysis, a statistically significant difference (p ≤.01) was found in terms of yield from the application of inoculum. Compared to the control in wheat cultivars, there was a 52.15% decrease in the yield of infected parcels due to the damage of wheat seed gall nematode. The highest yield loss in infected parcels occurred in cv. Damla with 64.22% loss, while the least yield loss occurred in cv. Yüksel cultivar with 19%. Pathological symptoms, curling and twisting of the leaves, were not observed on green plants of cv. Yüksel cultivated in the field. [ABSTRACT FROM AUTHOR]

There is a paucity of information on the relationship between anthers and Type II expression of Fusarium Head Blight resistance (measured by point inoculation of a spikelet and observing disease spread over the wheat spike). Twenty‐nine UK commercial wheat varieties were evaluated for the expression of Type II resistance. Anther extrusion was measured by counting the number of spikelets with anthers trapped between the lemma and palea (anthers trapped). In five spikelets where trapped anthers were not observed, the number of spikelets with anthers contained within the spikelet was counted (anthers retained). There was variation in expression in the expression of Type II resistance (p <.001), anthers trapped (p <.001) and anthers retained (p <.001). Anthers trapped and anthers retained were not correlated with each other, indicating both should be considered independently. Later maturity correlated with great resistance in the AHDB Type I resistance ratings but to greater susceptibility to point inoculations (Type II). Consistent with previous literature higher numbers of anthers trapped to increase susceptibility to FHB Type I. However, the relationships were reversed for the expression of resistance measured by point inoculation within the spikelet, where anthers trapped between the lemma and palea reduced susceptibility to Type II point inoculation (p <.01). This suggests a benefit of releasing some pollen from within the spikelet for this inoculation method. Similarly, anthers retained contributed to increased Type II susceptibility (p <.05), potentially providing substrates within the spikelet inoculation site aiding fungal growth, but correlated to greater Type I resistance (p <.05) indicating the anthers are hidden from initial infection on the outside of the spikelet, particularly under low infection pressure. While preliminary, this work suggests that variation in anthers trapped, anthers retained and maturity date may increase Type II expression of resistance and could relate to increased Type I FHB susceptibility. [ABSTRACT FROM AUTHOR]

BACKGROUND: Wild relatives of wheat (Triticum spp.) harbor beneficial alleles for potential improvement and de novo domestication of selected genotypes with advantageous traits. We analyzed the nutrient composition in wild diploid and tetraploid wheats and their domesticated diploid, tetraploid and hexaploid relatives under field conditions in Germany and compared them with modern Triticum aestivum and Triticum durum cultivars. Grain iron (Fe) and zinc (Zn) concentrations, phytate:mineral molar ratios, grain protein content (GPC) and antioxidant activity were analyzed across 125 genotypes. RESULTS: Grain Fe and Zn concentrations in wild wheats were 72 mg kg−1 and 59 mg kg−1, respectively, with improved bioavailability indicated by Phytate:Fe and Phytate:Zn molar ratios (11.7 and 16.9, respectively) and GPC (231 g kg−1). By comparison, grain Fe and Zn concentrations in landrace taxa were 54 mg kg−1 and 55 mg kg−1, respectively, with lower Phytate:Fe and Phytate:Zn molar ratios (15.1 and 17.5, respectively) and GPC (178 g kg−1). Average grain Fe accumulation in Triticum araraticum was 73 mg kg−1, reaching 116 mg kg−1, with high Fe bioavailability (Phyt:Fe: 11.7; minimum: 7.2). Wild wheats, landraces and modern cultivars showed no differences in antioxidant activity. Triticum zhukovskyi stood out with high grain micronutrient concentrations and favorable molar ratios. It was also the only taxon with elevated antioxidant activity. CONCLUSION: Our results indicate alteration of grain quality during domestication. T. araraticum has promising genotypes with advantageous grain quality characteristics that could be selected for de novo domestication. Favorable nutritional traits in the GGAA wheat lineage (T. araraticum and T. zhukovskyi) hold promise for improving grain quality traits. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Deploying resistant wheat cultivars is the most economical and environment‐friendly strategy to manage the devastating effects of the dipteran pest, Hessian fly (Hf; Mayetiola destructor). Currently, 37 Hf resistance genes have been identified to combat the 18 Hf genotypes documented so far. However, the Hf populations adapt rapidly to overcome the newly deployed resistance genes within a few years of release resulting in development of virulent Hf biotypes and breakdown of plant resistance. Identification of new and novel sources of resistance offers breeders additional resources that can be included in the breeding programmes to develop elite Hf‐resistant cultivars. In the current study, we screened 374 wheat (tetraploid and hexaploid) accessions originating from different regions of the United States and identified three tetraploid (Triticum turgidum) pasta wheat lines, one originating from North Dakota (PI 639869) and two from Minnesota (PI 352398 and CItr 15710) exhibiting ≥95% resistance to Hf biotype L at 20°C. Further, the wheat cultivar PI 352398 showed 100% resistance to six additional Hf genotypes including biotypes B, C, D, O, GP and vH13. The lines PI 639869 and CItr 15710 also showed >70% resistance with most biotypes, except against biotype GP with the former and biotype B with the latter. Interestingly, a few plants from these two cultivars exhibited putative tolerance to these biotypes where the plants showed normal growth but harboured white, live larvae and showed cell permeability that was intermediate in levels between Hf‐infested resistant and susceptible wheat. Additionally, since the increase in environmental temperatures to 25–30°C also negatively impacts Hf resistance, the three T. turgidum (PI 639869, PI 352398 and CItr 15710) cultivars were evaluated for Hf resistance at 30°C. None of the wheat cultivars were resistant to Hf biotype L at 30°C indicating a temperature‐dependent breakdown of resistance and are therefore not suitable for geographical regions with higher environmental temperatures. Taken together, these three wheat lines represent additional sources of Hf resistance that can be leveraged by breeders for developing durable elite lines. [ABSTRACT FROM AUTHOR]

'FL16045‐25' (Reg. no. CV‐1207, PI 704484), a soft red, facultative doubled‐haploid wheat (Triticum aestivum L.) cultivar, was developed and tested as FL16045DH‐25 by the University of Florida and released in October 2022. FL16045‐25 was derived from the cross MD07W478‐14‐5/GA06112‐13EE16. It is well adapted from Texas to Virginia and provides producers with an early‐season, facultative (Vrn‐A1_short), medium‐height, awned, semi‐dwarf (Rht2) cultivar that has high yield potential, good straw strength, good grain volume weight, and good end‐use quality. It expresses moderate‐to‐high levels of resistance to most diseases prevalent in the southern United States. Molecular marker analysis confirms the presence of Sbm1, Yr17/Lr37/Sr38, Lr18, Sr36/Pm6, Pm54, and Pm1a‐linked disease‐resistant genes. The yield average of FL16045‐25 from 41 environments during 2020–2022 ranged from 4211 to 5782 kg ha−1, which is competitive with check cultivars that are widely used in the southern part of the United States. The grain volume weight of FL16045‐25 ranged from 749 to 785 kg m−3 (32 environments), which was higher than most of the checks. FL16045‐25 has soft grain texture with softness equivalence varying from 51.3% to 59.3% and sodium carbonate solvent retention capacity (SRC) ranging from 66.8% to 68.5%. Flour yields on a Quadrumat Senior milling system varied from 68.7% to 69.5%. Flour protein content varied from 8.9% to 9.1%. Cookie spread diameter varied from 19.4 to 19.5 cm. The presence of TaSus2‐2B, Sucrose Synthase2 gene on 2B or 2G:2B, was confirmed by marker analysis. Core Ideas: FL16045‐25 is an early‐maturing, facultative, medium‐height wheat cultivar broadly adapted to the southern United States.FL16045‐25 has high yield potential and good straw strength, grain volume weight, and end‐use quality.FL16045‐25 demonstrated moderate‐to‐high levels of resistance to most diseases prevalent in the southern United States.Molecular marker analysis confirms the presence of Sbm1, Yr17/Lr37/Sr38, Lr18, Sr36/Pm6, Pm54, and Pm1a genes.It has above‐average resistance to Fusarium head blight disease. [ABSTRACT FROM AUTHOR]

USDA National Agricultural Statistics Service general crop condition data are used to quantify the relationship between crop conditions and yield, condition tendencies during the growing season, how conditions vary across the United States, and how conditions have trended for the 1986–2022 period for a variety of crops: barley (Hordeum vulgare L.), corn (Zea mays L.), cotton (Gossypium hirsutum L.), oats (Avena sativa L.), peanuts (Arachis hypogaea L.), rice (Oryza sativa L.), sorghum (Sorghum bicolor L.), soybeans (Glycine max L.), and spring and winter wheat (Triticum aestivum L.). Crop conditions are a statistically significant covariate (90% significance level) for yield and can be used in practice on a weekly basis. This becomes increasingly important as, historically, crop conditions not only deteriorated on average, but also became more variable throughout the growing season. Spatial differences in conditions, variability, and trends in condition ratings and variability are caused by crop selection, regional climate, and management practices such as irrigation. Crop conditions were poorest and had the highest interannual variability across the southern Great Plains region. Since 1986, crop conditions in the Great Plains region have deteriorated significantly, while variability has increased. Meanwhile, crop conditions across the southwestern and southeastern United States have significantly improved, while interannual variability in conditions has experienced robust declines. Given climatic and hydrologic trends, to maintain a positive trend in yield, continued advancements in production management and technology are required. Critical decisions regarding real‐time or future management can be supplemented by using crop condition risk assessment information along with actively monitoring weekly conditions. Core Ideas: USDA crop condition ratings are a statistically significant covariate for yield and can be used in practice.Crop conditions tend to deteriorate as the season progresses while historically variability increases.Crop conditions were poorest on average and had the highest interannual variability in the southern Great Plains.Since 1986, crop conditions in the Great Plains have deteriorated significantly while variability has increased.The southwestern and southeastern United States significantly improved in crop conditions, while variability decreased. [ABSTRACT FROM AUTHOR]

Source-sink relationships influence photosynthesis. So far, the limiting factors for photosynthesis of wheat cultivars with different source-sink relationships have not been determined. We aimed to determine the variation patterns of photosynthetic characteristics of wheat cultivars with different source-sink relationships. In this study, two wheat cultivars with different source-sink relationships were selected for photosynthetic physiological analyses. The results showed that YM25 (source-limited cultivar) had higher photosynthetic efficiency compared to YM1 (sink-limited cultivar). This is mainly due to a stronger photochemical efficiency, electron transfer capacity, and Rubisco carboxylation capacity of YM25. YM25 accumulated less soluble carbohydrates in flag leaves than YM1. This is mainly due to the stronger sucrose synthesis and transport capacity of YM25 by presenting higher sucrose-related enzyme activities and gene expression. A PCA analysis showed that Rubisco was the main factor limiting the photosynthetic capacity of YM25. The soluble sugar accumulation in flag leaves and sink limitation decreased the photosynthetic activity of YM1. Increased N application improved source-sink relationships and increased grain yield and source leaf photosynthetic capacity in both two wheat cultivars. Taken together, our findings suggest that Rubisco and sucrose synthesis and translocation are involved in the regulation of photosynthesis of wheat cultivars with different sourcesink relationships and that source and sink limitation effects should be considered in photosynthesis. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) root‐associated microbes play an indispensable role in helping plants obtain phosphorus (P) from soil. However, the relationships among soil P content, wheat root‐associated microorganisms, and plants are still not fully understood. Therefore, revealing the effects of soil P content on the root‐associated microbes in different crop varieties at different growth stages is important for plant nutrient management. In this study, the variations of prokaryotic communities were investigated in the endosphere and rhizosphere of three wheat varieties growing in soils with different P content and at different growth stages. The key findings indicated that compartment niche and growth stage were the primary factors to shape wheat root‐associated prokaryotic community assembly under different soil P contents. Soil P content mainly affected the prokaryotic community in rhizosphere rather than in endosphere. The effects of soil P content on root‐associated prokaryotic communities in different wheat varieties were different and varied with the growth stage. Under low P treatment, there was greater variation in prokaryotic communities among varieties. In addition, compared with that in P‐deficient soil, wheat rhizosphere enriched more taxa and functions related to plant growth in the P‐sufficient soil. P‐efficient variety (ZGC) enriched more genera that were positively related to plant growth in P‐sufficient soil. This study comprehensively revealed the influences of soil P content on wheat root‐associated prokaryotic communities, and the relationships among soil P content, wheat root‐associated prokaryotic community, and plant. Core Ideas: The effect of phosphorus (P) content on wheat root‐associated prokaryotic community depends on the growth stage and variety.Low P stress exacerbates community variation among varieties.P addition promotes the formation of mutually beneficial relationships between microorganisms and plants.P‐efficient variety enriches more potential beneficial genera in P‐sufficient soil. [ABSTRACT FROM AUTHOR]

Wheat leaf rust, caused by Puccinia triticina, is reported annually in southern Russia, the main wheat production region in Russia. The effect of biotic (types of cultivar resistance) and abiotic (northern, central and southern agro‐ecological zones) factors on virulence variability of the pathogen was analysed with 43 Lr differentials. Virulence frequencies to Lr genes 1, 2c, 3, 3bg, 11, 14a, 14b, 16, 17, 18, 23, 25, 26, 33, 34, 40 and Kanr exceeded 50% in all populations. A total of 81 virulence phenotypes (based on the standard set of 20 differentials) were identified among 108 isolates. The most common phenotypes were PHSTQ, THTTR, PHTTR and TKTTR. The minimum genetic distance (the highest similarity) was established between the P. triticina populations from susceptible cv. Krasnodarskaya 99 and cv. Brigada with race‐specific resistance. P. triticina populations from the susceptible cultivar in the three agro‐ecological zones were less variable and more similar than the cultivar‐specific and natural pathogen populations. Resistance types of host cultivars seem to have a greater effect on the pathogen population than abiotic factors. Nevertheless, abiotic factors need to be considered when making decisions about deployment of wheat varieties. Our results support the paradigm of a shift in the population of an obligate parasite towards increased virulence in response to the selection pressure of cultivars with race‐specific resistance. [ABSTRACT FROM AUTHOR]

SUMMARY: Heterosis, also known as hybrid vigor, is the phenomenon wherein a progeny exhibits superior traits relative to one or both parents. In terms of crop breeding, this usually refers to the yield advantage of F1 hybrids over both inbred parents. The development of high‐yielding hybrid cultivars across a wider range of crops is key to meeting future food demands. However, conventional hybrid breeding strategies are proving to be exceptionally challenging to apply commercially in many self‐pollinating crops, particularly wheat and barley. Currently in these crops, the relative performance advantage of hybrids over inbred line cultivars does not outweigh the cost of hybrid seed production. Here, we review the genetic basis of heterosis, discuss the challenges in hybrid breeding, and propose a strategy to recruit multiple heterosis‐associated genes to develop lines with improved agronomic characteristics. This strategy leverages modern genetic engineering tools to synthesize supergenes by fusing multiple heterotic alleles across multiple heterosis‐associated loci. We outline a plan to assess the feasibility of this approach to improve line performance using barley (Hordeum vulgare) as the model self‐pollinating crop species, and a few heterosis‐associated genes. The proposed method can be applied to all crops for which heterotic gene combinations can be identified. Significance Statement: This perspective summarizes key hypotheses on the genetic basis of heterosis, assesses challenges in hybrid breeding of self‐pollinating crops, and proposes an approach using synthetic supergenes to exploit heterosis. [ABSTRACT FROM AUTHOR]

Studying the long‐term effect of elevated atmospheric CO2 concentration (e[CO2]) on wheat (Triticum aestivum L.) over multiple generations has received increasing attention. Here, five wheat cultivars were grown under ambient CO2 concentration (a[CO2], 400 ppm) and e[CO2] (800 ppm), respectively, for three consecutive generations (G1 to G3) under two nitrogen (N) levels (1N and 2N). Compared to plants grown under a[CO2], e[CO2] increased shoot biomass and grain yield (GY) over three generations and the enhancement was greater in G3 than in G1. However, plant N concentration was lowered by e[CO2] and the reduction was not mitigated by higher N supply. The carbon (C) concentration significantly increased in leaf and stem but decreased in grain, indicating an inhibited C translocation to grain under e[CO2]. Most importantly, these negative impacts were exacerbated in G3. Concentrations of mineral nutrients in grain were significantly lowered by e[CO2] with larger reduction in G3 than in G1 in some micronutrients such as Zn, Cu and Fe. These findings suggest that long‐term exposure to e[CO2] sustained the positive effects on plant growth and production but aggravated the reduction of grain quality over multiple generations. Among the five cultivars, 325Jimai showed the greatest increase in shoot biomass and GY, and a greater sink capacity compared with the other cultivars, indicating its potential for future breeding strategies. [ABSTRACT FROM AUTHOR]

Copyright of Agronomy Journal is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Agronomy Journal is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Agronomy Journal is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Summary: Staying ahead of the arms race against rust and mildew diseases in cereal crops is essential to maintain and preserve food security. The methodological challenges associated with conventional resistance breeding are major bottlenecks for deploying resistance (R) genes in high‐yielding crop varieties. Advancements in our knowledge of plant genomes, structural mechanisms, innovations in bioinformatics, and improved plant transformation techniques have alleviated this bottleneck by permitting rapid gene isolation, functional studies, directed engineering of synthetic resistance and precise genome manipulation in elite crop cultivars. Most cloned cereal R genes encode canonical immune receptors which, on their own, are prone to being overcome through selection for resistance‐evading pathogenic strains. However, the increasingly large repertoire of cloned R genes permits multi‐gene stacking that, in principle, should provide longer‐lasting resistance. This review discusses how these genomics‐enabled developments are leading to new breeding and biotechnological opportunities to achieve durable rust and powdery mildew control in cereals. [ABSTRACT FROM AUTHOR]

Context: The nutritional value of enzyme‐supplemented wheat‐contained diets can be influenced by interactions between wheat cultivar and exogenous enzyme, which in turn cause various effects on the performance of poultry. Aims: The effects of diets including various wheat cultivars with or without enzyme on productive performance and egg quality characteristics were evaluated. Methods: A total of 270 58‐week‐old Lohmann LSL‐Lite were allocated to 9 experimental dietary groups with 5 replicate cages and 6 birds per each cage. Based on a 4 × 2 factorial arrangement of treatment, nine iso‐caloric and iso‐nitrogenous experimental diets, including four wheat cultivars (Sardari, Azar 2, Pishgam and Sirvan) with and without enzymes plus a corn‐based control diet, were tested in a completely randomized design during an 8‐week trial period. Key results: From weeks 58 to 63 and 63 to 67 of age, the hens fed with Sardari‐included diet showed the lowest feed intake compared to other groups (p < 0.05). Egg production (EP), feed conversion ratio (FCR) and egg mass (EM) were not influenced by the experimental diets. At the age of 62 weeks, the effect of adding enzyme on egg shape index was significant. Moreover, in sampling week 67, increased eggshell weight (%) was detected in enzyme‐supplemented diets compared to diets with no enzyme (10.03 vs. 9.37, respectively). Besides, the shell thickness was the highest in the group fed with Azar 2, and the lowest in the group fed with Sirvan at the age of 67 weeks (p < 0.05). Albumen weights (%) were also significant in some cases. The highest albumen weight was observed in Sirvan‐included diet without enzyme on week 62. Reduced yolk weight was detected in enzyme‐supplemented Pishgam‐included diet on 62 weeks of age (p < 0.05). Conclusions: The inclusion of the diets of laying hens with the four tested Iranian wheat cultivars has no negative impact on most productive performance and egg quality indices. Moreover, supplementing the wheat‐included diets with non‐starch polysaccharidase enzyme (beta‐endopower) improved eggshell weight on week 67. [ABSTRACT FROM AUTHOR]

A long‐term goal of breeders and researchers is to develop crop varieties that can resist environmental stressors and produce high yields. However, prioritising yield often compromises improvement of other key traits, including grain quality, which is tedious and time‐consuming to measure because of the frequent involvement of destructive phenotyping methods. Recently, non‐destructive methods such as hyperspectral imaging (HSI) have gained attention in the food industry for studying wheat grain quality. HSI can quantify variations in individual grains, helping to differentiate high‐quality grains from those of low quality. In this review, we discuss the reduction of wheat genetic diversity underlying grain quality traits due to modern breeding, key traits for grain quality, traditional methods for studying grain quality and the application of HSI to study grain quality traits in wheat and its scope in breeding. Our critical review of literature on wheat domestication, grain quality traits and innovative technology introduces approaches that could help improve grain quality in wheat. [ABSTRACT FROM AUTHOR]

Determining the stability and consistency of grain yield performance requires accurate evaluation of genotypes in different environments. In Mexico, annual national spring wheat irrigated trials (ENTRI) are conducted to assess elite bread (Triticum aestivum L.) and durum (Triticum durum L.) wheat performance in different testing environments (TEs) in the main wheat‐growing areas. These trials provide data supporting release of new cultivars and aim to also address Mexican wheat value chain grain needs. This study analyzed grain yield performance of 30 bread and durum wheat cultivars grown in trials in the 2012–2013 and 2013–2014 growing cycles conducted across TEs in northwest, north, and central Mexico. Environmental variability (location, sowing timing, and irrigation schemes) across the ENTRI enabled genotype by environment interaction to be effectively evaluated. Bread and durum wheat genotypes with high and stable grain yield were also identified and compared across TEs of the wheat‐growing areas of Mexico. The bread wheat cultivars Bacorehuis F2015 and Borlaug100 F2014, and the durum cultivars Barobampo C2015, CONASIST C2015, and Anatoly C2011 were high yielding and gave stable performance in most of the TEs. This analysis demonstrates the utility of multi‐year, multi‐environment testing and analysis to identify improved wheat cultivars to meet wheat production demand in Mexico. It also provides useful testing and analysis methods for selection of suitable broadly as well as locally adapted varieties in other wheat producing regions of the world. Core Ideas: We identified cultivars with high and stable grain yield in Mexico.Environmental variability enabled G × E interaction to be effectively evaluated.Multi‐year, multi‐environment testing and analysis is useful to identify improved wheat cultivars. [ABSTRACT FROM AUTHOR]

Reducing generation time is critical to achieving the goals of genetic gain in important crops like wheat (Triticum aestivum). Speed breeding (SB) has been shown to considerably reduce generation times in crop plants. Unlike spring wheat cultivars, winter wheat varieties require typically 6–9 weeks of cold treatment, called vernalization, for flowering which extends the generation time for the development of improved winter wheat cultivars. Here, we optimized the SB method using a set of 48 diverse soft red winter wheat (SRWW) cultivars by testing vernalization duration, light and temperature requirements, and the viability of seeds harvested after different durations post‐anthesis under extended daylight conditions. We have found that using a 22‐h setting (22 h day/2 h night, 25°C/22°C) in high‐density 50‐cell trays results in rapid generation advancement. We used genotypic data for a panel of soft red winter wheat varieties from the regional programs to determine the impact of photoperiod and vernalization alleles on the efficiency of the SB approach. Using a set of 48 SRWW cultivars and germplasm from Maryland and four other public breeding programs, we establish that this protocol can allow for the advancement of four generations per year in controlled conditions for winter wheat varieties, experimental lines, or emerging cultivars. Our work shows the potential to reduce generation time by ∼30 days per generation faster than what had been reported in the SB strategies for winter wheat, thus allowing for a quicker turnaround time from original cross to genetically stable experimental genotypes that can be tested in field settings. Core Ideas: The pace of generating improved winter wheat cultivars is enhanced using the speed breeding (SB) approach.Genetic gain is enhanced using the SB approach.The optimization of the SB method for diverse soft red winter wheat cultivars is illustrated. [ABSTRACT FROM AUTHOR]

Summary: Successful host colonization by plant pathogens requires the circumvention of host defense responses, frequently through sequence modifications in secreted pathogen proteins known as avirulence factors (Avrs). Although Avr sequences are often polymorphic, the contribution of these polymorphisms to virulence diversity in natural pathogen populations remains largely unexplored.We used molecular genetic tools to determine how natural sequence polymorphisms of the avirulence factor Avr3D1 in the wheat pathogen Zymoseptoria tritici contributed to adaptive changes in virulence.We showed that there is a continuous distribution in the magnitude of resistance triggered by different Avr3D1 isoforms and demonstrated that natural variation in an Avr gene can lead to a quantitative resistance phenotype. We further showed that homologues of Avr3D1 in two nonpathogenic sister species of Z. tritici are recognized by some wheat cultivars, suggesting that Avr‐R gene‐for‐gene interactions can contribute to nonhost resistance.We suggest that the mechanisms underlying host range, qualitative resistance, and quantitative resistance are not exclusive. See also the Commentary on this article by Rudd, 238: 1340–1342. [ABSTRACT FROM AUTHOR]

Producers desire cultivars that consistently perform with high yields and end‐use qualities. Unlike easily recognized average yield improvements, yield stability over time is less examined, especially when considering the role of breeding relative to other factors like management and changing climatic conditions. Our study system was a 70‐year historical dataset from which we estimated the year‐over‐year stability of winter wheat (Triticum aestivum L.) cultivars released by Montana's Agricultural Experimental Station. We examined yield stability within six locations representing diverse growing conditions across Montana and found no evidence that breeding has improved stability, that stability may be decreasing over time at one location, and that the year‐over‐year stability of a cultivar is sensitive to location. We examined the role of climatic conditions, including temperature, and rainfall to understand if increased climatic variability was masking improved patterns of stability. However, the lack of impact of breeding remained. These findings suggest that Montana's winter wheat may benefit from selective breeding for increased stability within locations. Core Ideas: While Montana's wheat yields have clearly improved over time, overall year‐over‐year stability appears stagnant.Examining wheat cultivars reveals a need for improved year‐over‐year stability over time.Weather variability contributes to but is not the major factor affecting year‐over‐year stability.Consideration of cultivar and location is critical to understanding year‐over‐year stability. [ABSTRACT FROM AUTHOR]

BACKGROUND: Selenium (Se) deficiency is a recognized problem that threatens the health of people worldwide, and wheat is grown worldwide and is one of the major sources of dietary Se. Since there are few studies that have investigated the changes in Se content and speciation of different varieties of Se‐enriched wheat from primary to deep processing, we studied four naturally Se‐enriched kinds of wheat and two Se‐fertilized kinds of wheat. RESULTS: Glutenin‑ and albumin‐bound Se accounted for the highest proportion of protein‐bound Se in refined wheat flour (7.29 ± 0.19 to 10.82 ± 0.50% and 6.16 ± 0.34 to 8.45 ± 0.07%); water‐soluble polysaccharide‐bound Se accounted for the highest proportion of polysaccharide‐bound Se in refined wheat flour (12.02 ± 0.54 to 24.62 ± 1.87%). Coarse bran Se content was significantly higher than refined wheat flour (137.94 ± 7.80 to 174.55 ± 5.09% for unpeeled wheat, 147.27 ± 10.96 to 187.72 ± 17.70% for peeled wheat). The peeling and processing of wheat into flour had different effects on Se the content and speciation dependent on the particular wheat variety. Whole wheat flour enabled better retention of selenomethionine (101.64 ± 2.32 to 138.41 ± 2.84% for unpeeled wheat, 158.59 ± 13.72 to 250.20 ± 4.94% for peeled wheat). The cooking process had no significant effect on Se content, but Se species were possibly interconverted. CONCLUSION: The organic Se content of different varieties of Se‐enriched wheat was different, but the milling and cooking process retained the total Se and Se speciation better, which could be used for daily Se supplementation for Se‐deficient people. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

To identify excellent cultivars resistant to Fusarium head blight (FHB), 104 wheat cultivars were tested by single‐flower inoculation using two prevalent pathogens from 2018 to 2020. Agronomic traits were also investigated. Six FHB‐resistance quantitative trait loci (QTL), Fhb1, Fhb2, Fhb4, Fhb5, Fhb7 and Qfhb.crc‐2D, have been assessed using previously reported DNA markers. A diagnostic marker has been used for Fhb1, and indicative markers linked to the other QTL were used. Results showed that (i) 12 (11.5%) cultivars were resistant to two pathogens in 3 years; among them, 'Shengxuan 6', 'Wanhongbian 759', 'Yunong 903' and 'Yunong 901' had good agronomic traits. (ii) Among cultivars with one resistance QTL, the severities of cultivars carrying Fhb1 and Qfhb.crc‐2D were 2.2 and 2.8, respectively, whereas those of cultivars with Fhb2 or Fhb7 were 3.6. Among cultivars with two resistance QTL, the severities of cultivars with Fhb1 + Fhb4, Fhb1 + Fhb7 and Fhb4 + Fhb5 were 2.2, 3.0 and 3.6, respectively. The severity of five cultivars possessing three or four resistance QTL was below 2.5. Fhb1 and Qfhb.crc‐2D showed better resistance effects than other resistance QTL. [ABSTRACT FROM AUTHOR]

BACKGROUND: Improving the nitrogen-use efficiency (NUE) of wheat can help mitigate the problems of poor soil fertility under dryland conditions. We conducted field experiments using three nitrogen (N) fertilization levels (0, 120, and 180 kg ha-1) applied to eight dryland wheat cultivars to assess NUE and its associated traits. RESULTS: The grain yield significantly increased with the improvement in variety, mainly as a result of a substantial increase in 1000-grain weight and harvest index. Modern wheat varieties have stabilized at an optimal plant height and exhibited improved performance in terms of NUE, partial N productivity, N harvest index, and grain protein content compared to older varieties. The NUE of wheat gradually increased with variety replacement. The net photosynthesis rate of the flag leaves in the filling stage improved with the year of cultivar release; Increasing soil-plant analysis development (SPAD) values of flag leaves in the flowering and filling stages were observed over time, with the flag leaves of modern varieties showing a high chlorophyll content in the filling stage. Additionally, the principal component analysis showed that the SPAD value, grain number per unit area, transpiration rate, leaf area, and grain protein content positively contributed to the clustering of the N180 and modern cultivars (from the 2000s to 2010s). CONCLUSION: Overall, high levels of N application did not significantly improve the NUE of wheat. However, modern wheat varieties can optimize N distribution, increase flag leaf photosynthetic capacity, and improve photosynthesis ability, thus enhancing NUE to achieve high yields under a suitable level of N supply. [ABSTRACT FROM AUTHOR]

Breeding programs aim to improve crop yield and environmental stability for enhanced food security. The principal methodology in breeding for stable yield gain relies on the indirect selection of beneficial genetics by yield evaluation across diverse environmental conditions. This methodology requires substantial resources while delivering a slow pace of yield gain and environmental adaptation. Alternative methods are required to accelerate gain and adaptation, becoming even more imperative in a changing climate. New molecular tools and approaches can enable accelerated creation and deployment of multiple alleles of genes identified to control key traits. With the advent of tools that enable breeding by targeted allelic selection, identifying gene targets associated with an improved crop performance ideotype will become crucial. Previous studies have shown that altered photoperiod regimes increase yield in wheat (Triticum aestivum). In the current study, we have employed such treatments to study the resulting yield ideotype in five spring wheat cultivars. We found that the photoperiod treatment creates a yield ideotype arising from delayed spike establishment rates that are accompanied by increased early shoot expression of TARGET OF EAT1 (TaTOE1) genes. Genes identified in this way could be used for ideotype‐based improve crop performance through targeted allele creation and selection in relevant environments. [ABSTRACT FROM AUTHOR]

Elevated atmospheric CO2 concentrations (e[CO2]) have a significant impact on plant physiology, grain yield and quality and the specific response of plants to e[CO2] is closely linked to cultivars. Here, five Chinese wheat (Triticum aestivum L.) cultivars were grown under ambient CO2 (a[CO2], 400 ppm) and e[CO2] (800 ppm). CO2 enrichment significantly increased net photosynthetic rate and water use efficiency but depressed stomatal conductance. e[CO2] increased the carbon (C) concentration but decreased the nitrogen (N) concentration in all five cultivars, whereas the effect of e[CO2] on grain yield was highly dependent on cultivar. Moreover, e[CO2] caused a significant reduction in grain minerals and protein, although the magnitude of reduction was different among these cultivars. The starch concentrations in the grains and flour viscosity were not significantly affected at e[CO2]. These findings improve our understanding of the interactive effect of CO2 conditions and cultivars on plant performances and provide a research basis to select suitable wheat cultivars to deal with food crisis in future climate. [ABSTRACT FROM AUTHOR]

Background: Cereal cultivars vary in root traits, and it can be proposed that wild forms and old cultivars are more adapted to using organic nitrogen (N) sources. Aims: Investigating N uptake from cover crop (CC) rhizodeposits by wheat and barley of different domestication level and their wild relatives, we expected a more efficient N uptake by wild forms and old cultivars, indicated by higher N uptake from rhizodeposits per root biomass. Methods: Eleven wheat and seven barley cultivars categorized into three domestication levels (wild, old, and modern) were grown under controlled conditions in pots with soil containing 15N‐labelled CC rhizodeposits. Shoot and root biomass, their 15N‐uptake, and a range of root traits were analyzed. Results: Domestication level was a weak predictor of root architecture. N taken up from rhizodeposits was similar in all plants at 14% of plant N. Cultivars with largest values for most root traits (e.g., root length or volume) and root to shoot ratio also showed largest total N uptake and N uptake from rhizodeposits. However, N uptake efficiency (N uptake from rhizodeposits per root biomass) was smallest for these cultivars. Two modern wheat cultivars showed the largest N uptake efficiency from CC rhizodeposits, whereas in barley a wild and an old cultivar showed the largest efficiency. Conclusions: In our study with a limited number of cultivars, domestication level is not related to the ability of cereals to take up N from CC rhizodeposits. The same proportion of N derived from rhizodeposits irrespective of cultivar or root traits indicates that the N provision from rhizodeposits was driven by other factors like mineralization. However, some cultivars had a larger N uptake efficiency. [ABSTRACT FROM AUTHOR]

Genetic manipulation of whole‐plant transpiration rate (TR) response to increasing atmospheric vapor pressure deficit (VPD) is a promising approach for crop adaptation to various drought regimes under current and future climates. Genotypes with a non‐linear TR response to VPD are expected to achieve yield gains under terminal drought, thanks to a water conservation strategy, while those with a linear response exhibit a consumptive strategy that is more adequate for well‐watered or transient‐drought environments. In wheat, previous efforts indicated that TR has a genetic basis under naturally fluctuating conditions, but because TR is responsive to variation in temperature, photosynthetically active radiation, and evaporative demand, the genetic basis of its response VPD per se has never been isolated. To address this, we developed a controlled‐environment gravimetric phenotyping approach where we imposed VPD regimes independent from other confounding environmental variables. We screened three nested association mapping populations totaling 150 lines, three times over a 3‐year period. The resulting dataset, based on phenotyping nearly 1400 plants, enabled constructing 63‐point response curves for each genotype, which were subjected to a genome‐wide association study. The analysis revealed a hotspot for TR response to VPD on chromosome 5A, with SNPs explaining up to 17% of the phenotypic variance. The key SNPs were found in haploblocks that are enriched in membrane‐associated genes, consistent with the hypothesized physiological determinants of the trait. These results indicate a promising potential for identifying new alleles and designing next‐gen wheat cultivars that are better adapted to current and future drought regimes. [ABSTRACT FROM AUTHOR]

Sensing of neighbours via the Red to Far‐Red light ratio (R:FR) may exert a cap to yield potential in wheat. The effects of an increased R:FR inside the canopy were studied in dense wheat mini canopies grown in controlled environments by lowering FR. To distinguish between effects exerted by light sensing and assimilate supply, the treatments were complemented with elevated CO2, applied between different developmental timepoints to specifically impact tillering, spike growth, floret fertility and grain filling, in different combinations. The yield response to high R:FR was strongly dependent on the developmental stage in all three cultivars and pivoted between positive if applied after the start of stem elongation, and negative or null if applied before. Yield gains of up to 70% and 120% were observed, respectively, in two cultivars, associated with a higher number of tiller spikes and grains per spike in the main shoot. The response to the combination of high R:FR and elevated CO2 or CO2 alone were cultivar dependent. Taken together, our results suggest that R:FR exerts a significant control on yield potential in wheat and achieving a high R:FR from stem elongation to maturity is a promising lever towards a significant increase in grain yield. "We demonstrate light quality is crucially important for wheat yield potential. Our study, using dense mini‐canopies under controlled conditions, shows a High Red:Far Red ratio (due to lower Far Red) during spike growth and grain filling almost doubles grain yield, probably by disrupting the perception of neighbours." [ABSTRACT FROM AUTHOR]

This study follows on from a previous study showing that binary mixtures of wheat cultivars affect the evolution of Zymoseptoria tritici populations within a field epidemic from the beginning (t1) to the end (t2) of a growing season. Here, we focused on the impact of interseason sexual reproduction on this evolution. We studied mixtures of susceptible and resistant cultivars (carrying Stb16q, a recently broken‐down resistance gene) in proportions of 0.25, 0.5 and 0.75, and their pure stands. We determined the virulence status of 1440 ascospore‐derived strains collected from each cultivar residue by phenotyping on seedlings. Virulence frequencies in the ascospore‐derived population were lower in mixtures than in pure stands of the resistant cultivar, especially in the susceptible cultivar residues, as at t2, revealing that the impact of mixtures persisted until the next epidemic season (t3). Surprisingly, after sexual reproduction the avirulence frequencies on the resistant cultivar residues increased in mixtures where the proportion of the susceptible cultivar was higher. Our findings highlight two epidemiological processes: selection within the pathogen population between t1 and t2 driven by asexual cross‐contamination between cultivars (previous study) and sexual crosses between avirulent and virulent strains between t2 and t3 driven by changes in the probabilities of physical encounters (this study). Mixtures therefore appear to be a promising strategy for the deployment of qualitative resistances, not only to limit the intensity of Septoria tritici blotch epidemics, but also to reduce the erosion of resistances by managing evolution of the pathogen population at a pluriannual scale. [ABSTRACT FROM AUTHOR]

Current efforts to reduce the maximum allowable cadmium (Cd) concentrations in wheat (Triticum aestivum L.) for at‐risk populations such as infants require sourcing wheat with low concentrations of Cd. Since Idaho (USA) is a major wheat supplier, there is a need to understand which varieties and locations in Idaho produce wheat containing low Cd. Therefore, the main objective of this paper is to report on a survey of total Cd concentrations in 469 wheat grain samples and 216 soil samples from several varieties and locations throughout Idaho. Total Cd concentrations in wheat grain ranged from <0.01 to 0.28 mg kg−1, varying by both wheat variety and location grown. Total soil Cd ranged from 0.450 to 1.85 mg kg−1. Bioaccumulation factor (BAF) was calculated by dividing the grain total Cd concentration by the soil total Cd concentration and ranged from 0.05 to 0.5. The variety 'UI Sparrow' had the lowest mean BAF (0.06), and several other varieties were also relatively low. Overall, almost all wheat varieties meet European Food Safety Authority (EFSA) requirements for Cd concentration for adult consumption. However, meeting the EFSA maximum allowable limit of Cd in infant food requires planting varieties noted for low Cd uptake, like UI Sparrow, and careful selection of growing regions with the lowest total soil Cd, such as northern, central, or western Idaho. Core Ideas: Cadmium concentrations in soil and wheat grain in Idaho (USA) were surveyed.Cadmium uptake in wheat is influenced by wheat variety and soil properties.Total cadmium in Idaho wheat grain ranges from <0.01 to 0.28 mg kg−1.Total cadmium in Idaho soils ranges from 0.45 to 1.85 mg kg−1.Bioaccumulation factor indicates the best varieties for producing wheat containing low cadmium. [ABSTRACT FROM AUTHOR]

Septoria tritici blotch (STB) is one of the main causes of wheat yield loss in the world. Apart from good agrotechnical practice, disease‐resistant cultivars are required to prevent yield losses. Breeding of such cultivars is time‐consuming and laborious, mainly due to the quantitative character of such resistance, but can be shortened using precise phenotyping. We show that fluorescence parameters, collected in a high‐throughput system, can be used for estimating wheat STB resistance. Using machine learning methods (deep learning network, random forest), we demonstrate that disease resistance based on the percentage of necrotic leaf area can be estimated by alterations in fluorescence parameters 8 days after inoculation, and before disease symptoms become visible. Moreover, we applied a random forest classifier to assess the significance of fluorescence parameters in an informative way (classification accuracy = 64.84%, p value [Accuracy >No information rate] <0.001). Based on this, we observed extensive alterations in parameters of sensitive cultivars, reflecting worse photosynthetic performance. The most highly altered parameters were fluorescence intensity measurements and descriptors of energy flux through photosystem II (PSII) reaction centres towards PSI such as F2, F3 and F4 fluorescence intensities at 0.1, 0.270 and 2 ms; initial to maximal fluorescence ratio (F0/Fm); the time derivative of relative variable fluorescence (dV/dT0); maximum quantum yield of PSII in the dark‐adapted state (Fv/Fm); maximum electron transport flux at PSII (ET0/RC); maximum trapped excitonic energy flux per excited PSII cross section (CS) at time T0 (TR0/CS0); and quantum efficiency of the reduction of end acceptors dR0 [dR0/(1 − dR0)]. [ABSTRACT FROM AUTHOR]

The plant rhizosphere bacterial community influences plant stress resistance. Stripe rust causes severe damage to wheat (Triticum aestivum L.) production. To reveal the composition and function of root bacterial communities in wheat cultivars with different stripe rust resistance, rhizosphere soil samples were collected from four wheat cultivars. High‐throughput 16S rRNA gene sequencing was used to study the rhizobacterial community structure and function in stripe rust‐resistant (Guinong 19 and Huamai 1223) and ‐susceptible (Mingxian 169 and Taichung 29) wheat cultivars. A total of 6,392 operational taxonomic units (OTUs) were detected, belonging to 29 bacterial phyla. Analysis showed the susceptible and resistant wheat cultivars had different microbial communities. Principal coordinate analysis showed that all wheat rhizosphere bacterial samples could be divided into two groups, according to different disease resistance. Linear discriminant analysis effect size analysis showed that different bacterial taxa were enriched in the rhizosphere soil between resistant and susceptible wheat cultivars. Functional analysis showed that the bacterial community in stripe rust‐resistant wheat had greater amino acid transport and metabolic functions. Our research not only provides basic knowledge of the composition of wheat‐related microbiota but also reveals the microbial taxa that could be integrated into the management strategy of wheat stripe rust. [ABSTRACT FROM AUTHOR]

Puccinia striiformis f. sp. tritici (Pst), the causal agent of stripe rust of wheat, is a highly evolving fungal pathogen and several widely deployed stripe rust resistance genes have been overcome worldwide often through single step increase in virulence. Development of stripe rust resistant cultivars depends on the availability of widely effective sources of resistance. An Indian wheat cultivar 'VL404' exhibited high level of resistance against Australian Pst pathotypes. 'VL404' was crossed with a susceptible genotype Avocet 'S' (AvS) and an F6 recombinant inbred line (RIL) population was developed. The VL404/AvS RIL population was evaluated at the seedling stage against three Pst pathotypes differing in their virulence profiles. Monogenic segregation for stripe rust response variation was observed in this population and the resistance locus was tentatively named YrVL. Incorporation of stripe rust data into the VL404/AvS genetic map constructed using 40K Wheat‐Barley Illumina XT single‐nucleotide polymorphism (SNP) array placed YrVL in the long arm of chromosome 2B in the 769.1–779.3 Mb region of the Chinese Spring physical map. YrVL was aligned with the previously reported genes in chromosome 2BL (Yr43, Yr72 and YrAW12) using Pretzel, and it was placed distal to all these genes. Hence, YrVL appears to represent a new resistance locus. [ABSTRACT FROM AUTHOR]

Spring wheat is currently dominating wheat production in Norway. The introduction of combine harvesting in the 1950s spurred breeding efforts to improve lodging and preharvest sprouting resistance, and to integrate good breadmaking quality in the locally adapted germplasm. Release of landmark cultivars Runar and Reno in the 1970s revitalized the country's production and marked the onset of modern wheat cultivation in Norway. Since that time, new cultivars have been developed but little is known about the genetic basis of the achieved yield gains. We collected 21 representative cultivars released since 1972 in Norway and tested them in a multiyear field trial including two fertilization rates: 75 and 150 kg ha–1 N. We assessed grain yield, plant height, heading, maturity, length of grain filling period, grain protein content, protein yield, aboveground biomass, harvest index, grain weight, test weight, grains per spike, grains per square meter, and spikes per square meter and their response to fertilization. We document an annual increase in grain yield of 17.8 kg ha–1 (0.34%), at both rates of N fertilization. None of the traits exhibited significant genotype × management interaction. Wheat breeding has led to the development of higher‐yielding cultivars with higher protein yield that mature later, have a prolonged grain‐filling period, and produce more grains per spike and grains per unit area. Core Ideas: Grain yield in the 1972–2019 period increased by 17.8 kg ha−1 (0.34%) per year due to improved cultivars.Grain yield gains do not rely on intensive N fertilization.Cultivars do not exhibit significant genotype × management interactions for any of the measured traits.Breeding in Norway since 1972 caused the cultivars to have a 2‐d longer grain‐filling period and reach physiological maturity 3 d later.New cultivars in Norway produce more grains per spike and grains per unit area. [ABSTRACT FROM AUTHOR]

Creating new genetic variation by crossing two or more parents is the initial and often most important step when developing new crop varieties. Hence, several mate selection indices have been suggested to support the planning of crosses in genomic breeding pipelines that have been established in many breeding programmes in recent years. The corresponding index weights are however difficult to determine objectively, and these indices often feature weights determined by laborious grid searches or rules of thumb. The aim of this study was to compare methods that employ the latter approach with mate selection indices based on desired gains in simulations and an empirical Fusarium head blight experiment for winter wheat. The results indicated that the suggested desired gain indices outperform routinely used methods in terms of reaching a favourable balance between the short‐term selection gain, long‐term selection gain, as well as the genetic diversity. They might have beyond that a high prospect for making a broader spectrum of genetic diversity accessible in the framework of germplasm exchange between breeding programmes. [ABSTRACT FROM AUTHOR]

High temperatures and increasing CO2 concentrations are a major threat to global wheat (Triticum aestivum L.) production, demanding the development of heat‐tolerant wheat cultivars. Plant physiological traits are potential surrogates for evaluating genetic variation for crop stress tolerance. This research evaluated 23 Australian wheat cultivars and two breeding lines for heat‐tolerance by characterising the associated physiological traits. The interactive effects of heat‐stress and elevated CO2 were studied under controlled greenhouse conditions and delayed sowing in the field with exposure to higher temperature. Physiological changes, pollen viability and grain yield were assessed. A significant correlation was observed between physiological and agronomical traits under high temperature at 35°C and elevated CO2 at 800 µl L−1, providing evidence of adaptation to high temperatures in some genotypes. Variation in stomatal conductance, transpiration rate, canopy temperature, leaf chlorophyll and photosynthesis were associated with maintenance of pollen viability and grain yield at high temperatures. Of the genotypes assessed, seven were classified as heat tolerant at both ambient and elevated CO2 and nine were heat susceptible while the remainder showed a variable response to CO2 at high temperatures. Field data confirmed the heat responses of the most heat‐tolerant and susceptible genotypes. The heat tolerant genotypes identified are candidates for further breeding and selection to improve adaptation to a changing climate. [ABSTRACT FROM AUTHOR]

High temperatures and increasing CO2 concentrations are a major threat to global wheat (Triticum aestivum L.) production, demanding the development of heat‐tolerant wheat cultivars. Plant physiological traits are potential surrogates for evaluating genetic variation for crop stress tolerance. This research evaluated 23 Australian wheat cultivars and two breeding lines for heat‐tolerance by characterising the associated physiological traits. The interactive effects of heat‐stress and elevated CO2 were studied under controlled greenhouse conditions and delayed sowing in the field with exposure to higher temperature. Physiological changes, pollen viability and grain yield were assessed. A significant correlation was observed between physiological and agronomical traits under high temperature at 35°C and elevated CO2 at 800 µl L−1, providing evidence of adaptation to high temperatures in some genotypes. Variation in stomatal conductance, transpiration rate, canopy temperature, leaf chlorophyll and photosynthesis were associated with maintenance of pollen viability and grain yield at high temperatures. Of the genotypes assessed, seven were classified as heat tolerant at both ambient and elevated CO2 and nine were heat susceptible while the remainder showed a variable response to CO2 at high temperatures. Field data confirmed the heat responses of the most heat‐tolerant and susceptible genotypes. The heat tolerant genotypes identified are candidates for further breeding and selection to improve adaptation to a changing climate. [ABSTRACT FROM AUTHOR]

Cultivar mixtures slow polycyclic epidemics but may also affect the evolution of pathogen populations by diversifying the selection pressures exerted by their plant hosts at field scale. We compared the dynamics of natural populations of the fungal pathogen Zymoseptoria tritici in pure stands and in three binary mixtures of wheat cultivars (one susceptible cultivar and one cultivar carrying the recently broken‐down Stb16q gene) over two annual field epidemics. We combined analyses of population "size" based on disease severity, and of population "composition" based on changes in the frequency of virulence against Stb16q in seedling assays with more than 3000 strains. Disease reductions were observed in mixtures late in the epidemic, at the whole‐canopy scale and on both cultivars, suggesting the existence of a reciprocal protective effect. The three cultivar proportions in the mixtures (0.25, 0.5, and 0.75) modulated the decrease in (a) the size of the pathogen population relative to the two pure stands, (b) the size of the virulent subpopulation, and (c) the frequency of virulence relative to the pure stand of the cultivar carrying Stb16q. Our findings suggest that optimal proportions may differ slightly between the three indicators considered. We argue potential trade‐offs that should be taken into account when deploying a resistance gene in cultivar mixtures: between the dual objectives "efficacy" and "durability," and between the "size" and "frequency" of the virulent subpopulation. Based on current knowledge, it remains unclear whether virulent subpopulation size or frequency has the largest influence on interepidemic virulence transmission. [ABSTRACT FROM AUTHOR]

It is important to understand the genetic gain achieved through selection of key yield traits for planning future breeding strategies in developing high yielding wheat (Triticum aestivum L.) cultivars. The aim of this study was to characterize the genetic changes and genotype × environment (G×E) interaction by additive main effect and multiplicative interactions (AMMI) for morphological, physiological, and yield component traits under five environments using 24 wheat cultivars released from 1911 to 2016 in Pakistan. There was a significant increase in grain yield (9.03 kg ha−1 yr−1, 0.37%), and plant height was reduced linearly (−0.26 cm yr−1, −0.33%). The traits waxiness, leaf rolling, harvest index, spike length, and grains per spike significantly increased but the gain was only 0.16–0.2% per year. Analysis of variance revealed that genotype, environment, and G×E interaction were highly significant (P <.01) for all traits except relative chlorophyll content, biomass, days to maturity, and number of spikes. Gene‐specific markers identified the durable resistance gene Lr67/Yr46/Sr55/Pm46 in obsolete cultivars as early as 1911, whereas the photoperiod‐insensitive allele Ppd‐D1a and reduced height alleles Rht‐B1b and Rht‐D1b were present only in the post‐1965 cultivars. Diversity analysis based on a 50K single nucleotide polymorphism genotyping array clearly differentiated temporal patterns in 24 cultivars, which was correlated with the agronomic performance of the cultivars. This dataset provided detailed insight into the performance of historical wheat cultivars and could help in devising wheat breeding strategies to focus on the traits contributing to grain yield and have slower rate of genetic progress. Core Ideas: The genetic gain in morphology of Pakistani bread wheat cultivars over 105 yr areas was assessed.Leaf rolling, waxiness, and grains/spikes associated with genetic gains in grain yield were achieved by breeding.The performance and stability of yield and yield‐related traits was analyzed for the different cultivars. [ABSTRACT FROM AUTHOR]

The adoption of improved crop varieties, such as drought‐tolerant varieties, plays a crucial role in addressing climate change. In this study, we explore how and to what extent spatial interactions between farmers and neighboring farmers affect the adoption of drought‐tolerant wheat varieties (DTWVs), using data collected from rural households in China. A spatial Durbin probit model is utilized to identify the spatial patterns in DTWVs adoption. Results show that spatial dependence exists in DTWVs adoption. Spatial dependence is positively associated with wheat farmers' DTWVs adoption decisions, and the spatial effects mainly arise from the neighboring farmers' adoption decisions and information spillover via smartphone use and extension service contacts. Further analysis reveals that DTWVs adoption improves farm performance by increasing both wheat yields and farm profits significantly. Our findings underscore the necessity of considering spatial interactions between farmers when designing and promoting innovative agricultural technologies in rural areas. [ABSTRACT FROM AUTHOR]

Temperature is one of the most influential factors in crop phenology and is projected to increase substantially due to climate change. To adapt to climate change, it is necessary to understand how crops develop depending on cultivar choice, sowing time, and growing environment under various warming conditions. To clarify the influence of these interactions, we investigated 216 combinations of the genotype × environment × management interaction of wheat (Triticum aestivum L.) development. These included nine scenarios of constant and seasonal warming conditions, two cultivar types (spring‐type and winter‐type wheat), six sowing dates, and two cultivation environments (relatively cool or warm area), and the change in wheat heading dates was simulated using sigmoid and exponential function–based models. Simulations of growing conditions 1−5 °C above the average temperature during 1981–2010 resulted in the faster growth of spring‐type cultivars, and the earlier the cultivars were sown, the faster they grew to heading stage. The winter‐type cultivars showed a smaller advancement to heading than the spring‐type cultivars, but the shortening period from sowing to heading became greater when grown in a cooler environment if the temperature significantly increased. In addition, increased temperatures in spring induced the advancement of heading more than similar conditions in winter. Our findings indicated that the advancement of the heading date varied greatly depending on the four‐factor combinations. Delaying sowing time and changing to winter‐type cultivars from spring‐type cultivars were thought to be effective adaptations; however, the adaptation strategies should be carefully planned depending on the agricultural management and warming conditions. Core Ideas: Wheat phenology was simulated under various farming and warming conditions.Simulations considered various cultivars, sowing dates, and growing environments.The advancement of wheat phenology varied substantially depending on these interactions.Delayed sowing and changing to winter from spring‐type cultivars are effective adaptations.Adaptations should be carefully planned considering these interactions. [ABSTRACT FROM AUTHOR]