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Drought is one of the most influential abiotic stress factors affecting bread wheat productivity worldwide. Therefore, the current experiment was conducted to evaluate the genetic variability presenting 19 bread wheat genotypes under two environments (normal and drought). Under normal conditions, grain yield per plant (GYP) exhibited the highest positive significant correlation with the number of grains per spike (NGS) (0.90***), biological yield (BY) (0.88***), 1000-grain weight (TGW) (0.83***), harvest index (HI) (0.77***), number of spikelets per spike (NSP) (0.52***), arithmetic mean diameter (AMD) (0.52***), grain mean diameter (GMD) (0.50***), equivalent mean diameter (EMD) (0.50***), grain length (GL) (0.46***), grain width (GW) (0.46***), grain thickness (GT) (0.34**), and spike length (SL) (0.27*). However, GYP showed a negative yet insignificant correlation with spike compactness (SC) (− 0.18) and peduncle length (PL) (− 0.08). Under drought stress, GYP exhibited a significantly positive association with BY (0.94***), HI (0.92***), NGS (0.86***), TGW (0.63***), aspect ratio (AR) (0.49***), grain sphericity (SPH) (0.40**), GW (0.39**), NSP (0.38***), and SL (0.28*). Principal component analysis (PCA) revealed that the first 4 PCs explained 88.9% and 87.4% of the variability under normal and drought-stress environments, respectively. Furthermore, cluster heat map classified genotypes into four different clusters. Under normal conditions, Cluster 4 contained the highest-performing genotypes for most of the traits, indicating their genetic relatedness. In contrast, under drought stress, the most tolerant genotype, G19, was present in Cluster 3. Consequently, the identified traits hold substantial significance as selection indicators in breeding programs to develop drought-resilient genotypes. [ABSTRACT FROM AUTHOR]

To meet the demands of a rising human population, plant breeders will need to develop improved crop varieties that maximize yield in the face of increasing pressure on crop production. Historically, the optimization of crop root architecture has represented a challenging breeding target due to the inaccessibility of the root systems. Root hairs, single cell projections from the root epidermis, are perhaps the most overlooked component of root architecture traits. Root hairs play a central role in facilitating water, nutrient uptake, and soil cohesion. Current root hair architectures may be suboptimal under future agricultural production regimes, coupled with an increasingly variable climate. Here, we review the genetic control of root hair development in the world's three most important crops—rice, maize, and wheat—and highlight conservation of gene function between monocots and the model dicot species Arabidopsis. Advances in genomic techniques including gene editing combined with traditional plant breeding methods have the potential to overcome many inherent issues associated with the design of improved root hair architectures. Ultimately, this will enable detailed characterization of the effects of contrasting root hair morphology strategies on crop yield and resilience, and the development of new varieties better adapted to deliver future food security. [ABSTRACT FROM AUTHOR]

Environmental stresses, including drought stress, seriously threaten food security. Previous studies reported that wheat F-box protein, TaFBA1, responds to abiotic stresses in tobacco. Here, we generated transgenic wheat with enhanced (overexpression, OE) or suppressed (RNA interference, RNAi) expression of TaFBA1. The TaFBA1-OE seedlings showed enhanced drought tolerance, as measured by survival rate and fresh weight under severe drought stress, whereas the RNAi plants showed the opposite phenotype. Furthermore, the OE plants had stronger antioxidant capacity compared to WT and RNAi plants and maintained stomatal opening, which resulted in higher water loss under drought stress. However, stronger water absorption capacity in OE roots contributed to higher relative water contents in leaves under drought stress. Moreover, the postponed stomatal closure in OE lines helped to maintain photosynthesis machinery to produce more photoassimilate and ultimately larger seed size. Transcriptomic analyses conducted on WT and OE plants showed that genes involved in antioxidant, fatty acid and lipid metabolism and cellulose synthesis were significantly induced by drought stress in the leaves of OE lines. Together, our studies determined that the F-box protein TaFBA1 modulated drought tolerance and affected yield in wheat and the TaFBA1 gene could provide a desirable target for further breeding of wheat. [ABSTRACT FROM AUTHOR]

Identifying stable quantitative trait loci (QTLs) for yield-related traits across populations and environments is crucial for wheat breeding and genetic studies. Consensus maps also play important roles in wheat genetic and genomic research. In the present study, a wheat consensus map was constructed using a doubled haploid (DH) population derived from Jinghua 1×Xiaobaidongmai (JX), an F2 population derived from L43×Shanxibaimai (LS) and the BAAFS Wheat 90K SNP array single nucleotide polymorphism (SNP) array. A total of 44,503 SNP markers were mapped on the constructed consensus map, and they covered 5,437.92 cM across 21 chromosomes. The consensus map showed high collinearity with the individual maps and the wheat reference genome IWGSC RefSeq v2.1. Phenotypic data on eight yield-related traits were collected in the JX population, as well as the F2:3 and F2:4 populations of LS, in six, two and two environments, respectively, and those data were used for QTL analysis. Inclusive composite interval mapping (ICIM) identified 32 environmentally stable QTLs for the eight yield-related traits. Among them, four QTLs (QPH.baafs-4B, QKNS.baafs-4B, QTGW.baafs-4B, and QSL.baafs-5A.3) were detected across mapping populations and environments, and nine stable QTLs (qKL.baafs-1D, QPH.baafs-2B, QKNS.baafs-3D, QSL.baafs-3D, QKW.baafs-4B, QPH.baafs-5D, QPH.baafs-6A.1, QSL.baafs-6A, and QSL.baafs-6D) are likely to be new. The physical region of 17.25–44.91 Mb on chromosome 4B was associated with six yield-related traits, so it is an important region for wheat yield. The physical region around the dwarfing gene Rht24 contained QTLs for kernel length (KL), kernel width (KW), spike length (SL), and thousand-grain weight (TGW), which are either from a pleiotropic effect of Rht24 or closely linked loci. For the stable QTLs, 254 promising candidate genes were identified. Among them, TraesCS5A03G1264300, TraesCS1B03G0624000 and TraesCS6A03G0697000 are particularly noteworthy since their homologous genes have similar functions for the corresponding traits. The constructed consensus map and the identified QTLs along with their candidate genes will facilitate the genetic dissection of wheat yield-related traits and accelerate the development of wheat cultivars with desirable plant morphology and high yield.

Abstract Background Drought stress limits significantly the crop productivity. However, plants have evolved various strategies to cope with the drought conditions by adopting complex molecular, biochemical, and physiological mechanisms. Members of the nuclear factor Y (NF-Y) transcription factor (TF) family constitute one of the largest TF classes and are involved in plant responses to abiotic stresses. Results TaNF-YB2, a NY-YB subfamily gene in T. aestivum, was characterized in this study focusing on its role in mediating plant adaptation to drought stress. Yeast two-hybrid (Y-2 H), biomolecular fluoresence complementation (BiFC), and Co-immunoprecipitation (Co-IP) assays indicated that TaNF-YB2 interacts with the NF-YA member TaNF-YA7 and NF-YC family member TaNF-YC7, which constitutes a heterotrimer TaNF-YB2/TaNF-YA7/TaNF-YC7. The TaNF-YB2 transcripts are induced in roots and aerial tissues upon drought signaling; GUS histochemical staining analysis demonstrated the roles of cis-regulatory elements ABRE and MYB situated in TaNF-YB2 promoter to contribute to target gene response to drought. Transgene analysis on TaNF-YB2 confirmed its functions in regulating drought adaptation via modulating stomata movement, osmolyte biosynthesis, and reactive oxygen species (ROS) homeostasis. TaNF-YB2 possessed the abilities in transcriptionally activating TaP5CS2, the P5CS family gene involving proline biosynthesis and TaSOD1, TaCAT5, and TaPOD5, the genes encoding antioxidant enzymes. Positive correlations were found between yield and the TaNF-YB2 transcripts in a core panel constituting 45 wheat cultivars under drought condition, in which two types of major haplotypes including TaNF-YB2-Hap1 and -Hap2 were included, with the former conferring more TaNF-YB2 transcripts and stronger plant drought tolerance. Conclusions TaNF-YB2 is transcriptional response to drought stress. It is an essential regulator in mediating plant drought adaptation by modulating the physiological processes associated with stomatal movement, osmolyte biosynthesis, and reactive oxygen species (ROS) homeostasis, depending on its role in transcriptionally regulating stress response genes. Our research deepens the understanding of plant drought stress underlying NF-Y TF family and provides gene resource in efforts for molecular breeding the drought-tolerant cultivars in T. aestivum.

Abstract Background This research explores the efficacy of mutagenesis, specifically using sodium azide (SA) and hydrazine hydrate (HZ) treatments, to introduce genetic diversity and enhance traits in three wheat (Triticum aestivum L.) genotypes. The experiment entails subjecting the seeds to different doses of SA and HZ and cultivating them in the field for two consecutive generations: M1 (first generation) and M2 (second generation). We then employed selective breeding techniques with Start Codon Targeted (SCoT) markers to select traits within the wheat gene pool. Also, the correlation between SCoT markers and specific agronomic traits provides insights into the genetic mechanisms underlying mutagenesis-induced changes in wheat. Results In the study, eleven genotypes were derived from parent varieties Sids1, Sids12, and Giza 168, and eight mutant genotypes were selected from the M1 generation and further cultivated to establish the M2 generation. The results revealed that various morphological and agronomical characteristics, such as plant height, spikes per plant, spike length, spikelet per spike, grains per spikelet, and 100-grain weight, showed increases in different genotypes from M1 to M2. SCoT markers were employed to assess genetic diversity among the eleven genotypes. The bioinformatics analysis identified a correlation between SCoT markers and the transcription factors ABSCISIC ACID INSENSITIVE3 (ABI3) and VIVIPAROUS1 (VP1), crucial for plant development, growth, and stress adaptation. A comprehensive examination of genetic distance and the function identification of gene-associated SCoT markers may provide valuable insights into the mechanisms by which SA and HZ act as mutagens, enhancing wheat agronomic qualities. Conclusions This study demonstrates the effective use of SA and HZ treatments to induce gene diversity through mutagenesis in the wheat gene pool, resulting in the enhancement of agronomic traits, as revealed by SCoT markers. The significant improvements in morphological and agronomical characteristics highlight the potential of mutagenesis techniques for crop improvement. These findings offer valuable information for breeders to develop effective breeding programs to enhance wheat quality and resilience through increased genetic diversity.

The applicable study assessed the impact of wheat (Triticum aestivum L.) cultivars and cytokinin (benzyl adenine) seed soaking on grain vitality, growth, and yield-related traits. The experiment materialized in the winter of 2022–2023 at the Al-Qasim Green University, Babylon, Iraq, laid out in a randomized complete block design with two factors. The first factor was cytokinin with three levels (100, 200, and 300 mg L-1), while the second factor was the four wheat cultivars (IPA 99, Bohuth 22, Babylon 113, and Mawadah). The wheat cultivar IPA 99 excelled in grains per spike (57.50) and biological yield (17.95 t ha-1), while the cultivar Mawadah stood out in spike m² (364.2), 1000-seed weight (46.87 mg) and grain yield (7.40 t ha-1). The cytokinin activation treatments varied significantly, and 200 mg L-1 treatment led to spike count (359.7), grain yield (7.20 t ha-1), and biological yield (18.06 t ha-1). The cytokinin (300 mg L-1) excelled in 1000-seed weight (47.20 mg). In their interaction, the cultivar Mawadah with cytokinin (200 mg L-1) exhibited the highest 1000-grain weight (51.38 mg) and grain yield (8.80 t ha-1). In conclusion, the study highlights the substantial influence of cytokinin treatments and wheat cultivars on key growth and yield parameters. [ABSTRACT FROM AUTHOR]

The most significant threat to global food security is water scarcity. Despite the fact that vermicompost (an effective organic fertilizer rich in humic substances, macro- and micro-nutrients, earthworm excretions, beneficial soil microbes, plant growth hormones, enzymes) and effective microorganisms (EM; photosynthetic bacteria, lactic acid bacteria, yeasts, actinomycetes, fermenting fungi) have been recognized as powerful strategies for alleviating environmental stresses, their combined effect has not been studied. Herein, as a first investigation, we aimed to enhance wheat's drought tolerance using an eco-friendly approach that combined vermicompost and EM. The study employed twelve treatments in a completely randomized design. The treatments included control, as well as single and combined applications of vermicompost and EM at three different irrigation levels (100%, 70%, and 30% of field capacity). Vermicompost and EM, applied singly or in combination, ameliorated drought-induced reduction in wheat growth and productivity by elevating photosynthetic pigment content, photochemical processes, Calvin cycle enzyme activity, net photosynthetic rate, transpiration rate, stomatal conductance, maximum quantum efficiency of PSII photochemistry, actual photochemical efficiency of PSII, electron transport rate, photochemical quenching coefficient, and effective quantum yield of PSII photochemistry. Additionally, adding vermicompost and/or EM improved wheat drought tolerance by increasing nutrient (nitrogen, phosphorus, potassium, iron, zinc, copper) acquisition, roots' ATP content, H+-pump activity, and membrane stability index while lowering hydrogen peroxide content, lipid peroxidation, and electrolyte leakage. The new evidence demonstrates that combining vermicompost with EM sustains wheat drought tolerance by regulating photosynthetic efficiency, nutrient acquisition, root H+-pump activity, and membrane stability. Overall, utilizing vermicompost/EM is a novel approach to improving plant physiological responses and overcoming drought-related challenges. [ABSTRACT FROM AUTHOR]

Background: Drought stress limits significantly the crop productivity. However, plants have evolved various strategies to cope with the drought conditions by adopting complex molecular, biochemical, and physiological mechanisms. Members of the nuclear factor Y (NF-Y) transcription factor (TF) family constitute one of the largest TF classes and are involved in plant responses to abiotic stresses. Results: TaNF-YB2, a NY-YB subfamily gene in T. aestivum, was characterized in this study focusing on its role in mediating plant adaptation to drought stress. Yeast two-hybrid (Y-2 H), biomolecular fluoresence complementation (BiFC), and Co-immunoprecipitation (Co-IP) assays indicated that TaNF-YB2 interacts with the NF-YA member TaNF-YA7 and NF-YC family member TaNF-YC7, which constitutes a heterotrimer TaNF-YB2/TaNF-YA7/TaNF-YC7. The TaNF-YB2 transcripts are induced in roots and aerial tissues upon drought signaling; GUS histochemical staining analysis demonstrated the roles of cis-regulatory elements ABRE and MYB situated in TaNF-YB2 promoter to contribute to target gene response to drought. Transgene analysis on TaNF-YB2 confirmed its functions in regulating drought adaptation via modulating stomata movement, osmolyte biosynthesis, and reactive oxygen species (ROS) homeostasis. TaNF-YB2 possessed the abilities in transcriptionally activating TaP5CS2, the P5CS family gene involving proline biosynthesis and TaSOD1, TaCAT5, and TaPOD5, the genes encoding antioxidant enzymes. Positive correlations were found between yield and the TaNF-YB2 transcripts in a core panel constituting 45 wheat cultivars under drought condition, in which two types of major haplotypes including TaNF-YB2-Hap1 and -Hap2 were included, with the former conferring more TaNF-YB2 transcripts and stronger plant drought tolerance. Conclusions: TaNF-YB2 is transcriptional response to drought stress. It is an essential regulator in mediating plant drought adaptation by modulating the physiological processes associated with stomatal movement, osmolyte biosynthesis, and reactive oxygen species (ROS) homeostasis, depending on its role in transcriptionally regulating stress response genes. Our research deepens the understanding of plant drought stress underlying NF-Y TF family and provides gene resource in efforts for molecular breeding the drought-tolerant cultivars in T. aestivum. [ABSTRACT FROM AUTHOR]

Background: This research explores the efficacy of mutagenesis, specifically using sodium azide (SA) and hydrazine hydrate (HZ) treatments, to introduce genetic diversity and enhance traits in three wheat (Triticum aestivum L.) genotypes. The experiment entails subjecting the seeds to different doses of SA and HZ and cultivating them in the field for two consecutive generations: M1 (first generation) and M2 (second generation). We then employed selective breeding techniques with Start Codon Targeted (SCoT) markers to select traits within the wheat gene pool. Also, the correlation between SCoT markers and specific agronomic traits provides insights into the genetic mechanisms underlying mutagenesis-induced changes in wheat. Results: In the study, eleven genotypes were derived from parent varieties Sids1, Sids12, and Giza 168, and eight mutant genotypes were selected from the M1 generation and further cultivated to establish the M2 generation. The results revealed that various morphological and agronomical characteristics, such as plant height, spikes per plant, spike length, spikelet per spike, grains per spikelet, and 100-grain weight, showed increases in different genotypes from M1 to M2. SCoT markers were employed to assess genetic diversity among the eleven genotypes. The bioinformatics analysis identified a correlation between SCoT markers and the transcription factors ABSCISIC ACID INSENSITIVE3 (ABI3) and VIVIPAROUS1 (VP1), crucial for plant development, growth, and stress adaptation. A comprehensive examination of genetic distance and the function identification of gene-associated SCoT markers may provide valuable insights into the mechanisms by which SA and HZ act as mutagens, enhancing wheat agronomic qualities. Conclusions: This study demonstrates the effective use of SA and HZ treatments to induce gene diversity through mutagenesis in the wheat gene pool, resulting in the enhancement of agronomic traits, as revealed by SCoT markers. The significant improvements in morphological and agronomical characteristics highlight the potential of mutagenesis techniques for crop improvement. These findings offer valuable information for breeders to develop effective breeding programs to enhance wheat quality and resilience through increased genetic diversity. [ABSTRACT FROM AUTHOR]

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Crop production decreases because of water deficit stress conditions worldwide. Understanding genetic variation in enzymes and physiological responses of wheat genotypes under drought conditions is necessary to select tolerant genotypes for cultivation under drought conditions. These goals set 15 wheat genotypes for cultivation in the fall of 2022 with two irrigation interval regimes to evaluate their growth and yield-related traits for drought tolerance. The experiment had a randomized complete block design with three replications. Results showed highly significant differences among studied genotypes for all assessed traits. Genotype G11 gave the highest values in aldehyde dehydrogenase activity, spike per meter, grain yield, and biological yield (9.620 milliunits/mL, 975.8 spikes m-1, 10.725 t ha-1, and 29.568 t ha-1, respectively). Genotype G1 emerges with the utmost value for glutamate dehydrogenase activity (9.62 milliunits/mL), G2 for tillers per meter (1030.0 tillers m-1 ), G4 for spike length (11.17 cm), G6 for 1000-grain weight (40.8 g), G12 for grains per spike (40.9 grain spike-1 ), and G14 for plant height (117.2 cm). Likewise, water level treatments exhibited a significant impact on the studied traits. However, genotype G11 was leading in grain and biological yields. The five-day irrigation interval treatment gave the highest values in all studied traits except for glutamate dehydrogenase activity. Therefore, the study concluded that wheat genotypes responded differently to water level treatments and water stress at 14-day irrigation intervals, which can benefit screening the wheat genotypes for water deficit stress. [ABSTRACT FROM AUTHOR]

Late sowing of wheat (Triticum aestivum L.) crop correlates with high temperatures. Thus, temperature is one of the main restraining factors influencing wheat yield productivity, especially during the grain-filling period. The best solution to this problem is to evolve heat-tolerant genotypes. Yet, heat tolerance is a complicated issue, causing it a challenge to make a reliable assessment of it. High-temperature stress is a chief ecological constraint hampering the productivity of hexaploid wheat in most parts of the globe. Wheat genotypes, which persist against abiotic stresses, especially at terminal stress periods, are options to meet Pakistan's food requirements in the coming years. In the current study, concerning SCA effects, the F1 hybrids, such as TD-1 × Kiran-95, NIA-Sarang × TJ-83, Benazir × AS-2002, TD-1 × Kiran-95, NIA-Sarang × Benazir, and TJ-83 × AS-2002, expressed rewarding SCA effects for several characteristics under the heat-stress environment; hence, they could be alternatives in future wheat breeding programs. Heterosis may further be a pursuit for these crosses to get the advantage of hybrid vigor. [ABSTRACT FROM AUTHOR]

Drought is an important stress affecting wheat production, which can reduce the quality of germination and seedling establishment. In order to understand the seed germination characteristics of wheat cultivars under drought stress, the germination characteristics under drought stress of 128 wheat cultivars widely used in production were identified by sand cultivation and water control method. Six wheat cultivars with significant differences in germination characteristics under drought stress ((Shannong 28 (SN28), Chang 6878 (C6878), Yannong 19 (YN19), Shannong 23 (SN23), Xinmai 296 (XM296), and Xinmai 38 (XM38)) were selected for physiological and biochemical analysis during seed germination under drought stress. The results showed that the germination characteristics under drought stress of 128 wheat cultivars were divided into 5 categories according to the drought tolerance coefficient of vigor index: good, the better, medium, the worse, and the worst. Eighteen wheat cultivars with good germination characteristics under drought stress, including SN28 and C6878, had fast seed germination and healthy seedlings. Twenty-six wheat cultivars with poor germination characteristics under drought stress, such as XM38 and- Lemai 185, had slow seed germination, dispersed germination time, low germination percentage (GP), and poor seedling uniformity. The physiological and biochemical indices of wheat cultivars with different germination characteristics under drought stress were further determined. The results showed that the relative expression level of TDP1 gene at the early stage of germination under drought in SN28 and C6878 with good germination characteristics under drought stress was significantly higher than the control. POD activity at the early stage of germination under drought was significantly higher than the control. The activities of α-amylase and cysteine protease were less affected by drought, and the soluble protein content at the late stage of germination was significantly higher than the control. However, the relative expression levels of DNA and protein repair genes in seed embryos of XM296 and XM38 with poor germination characteristics under drought stress were relatively delayed under drought stress. The activity of cysteine protease decreased significantly under drought stress. The above results indicated that wheat cultivars with good germination characteristics under drought stress showed strong macromolecular repair ability in seed embryos and antioxidant capacity in seed, early mobilization of storage substances during seed germination and seedling establishment under drought stress, and finally had fast germination speed and high seedling quality. [ABSTRACT FROM AUTHOR]

Due to the important process of global warming, the improvement of soil factors, which decrease wheat (Triticum aestivum L.) yield gap, in the arid and semi-arid areas of the world including Iran (Kerman province) is of significance. The objective was to determine how wheat yield gap and yield components, in 15 different fields (three different locations with areas ranging from 2993 to 5175 km2), are affected by soil physicochemical properties including texture, electrical conductivity (EC), pH, soil organic carbon (SOC), total nitrogen (TN), available phosphorus (P) and potassium (K), and chemical fertilization. Wheat yield components including tiller and grain number, fertile spike, spike length, 1000-grain weight (25–44 g), plant height, biological yield (plant dry weight) (4880–14800 kg/ha), and plant density were measured. Linear regression analyses indicated that SOC (0.23–1.51%), TN (0.02–0.15%) and available K (195–280 mg/kg) significantly affected wheat yield and yield components, which were also positively and significantly correlated. There was a positive and significant correlation between SOC, TN, and available P and K, which were negatively and significantly correlated with EC. The regression models relating soil physicochemical properties with spike length and plant height were significant (P ≤ 0.05). The R2 values ranged from 0.54 (number of grains per spike) to 0.90 (plant height) and for economic (grain) and biological yields were equal to 0.75 and 0.83, respectively. The yield gap was in the range of 1245–4256 kg/ha. The improvement of soil physicochemical properties may decrease wheat yield gap in the arid and semi-arid areas of the world. [ABSTRACT FROM AUTHOR]

Genetic variability and characters association studies play a pivotal role in enhancing selection efficiency under stress condition in plants. Therefore, the study was aimed at assessing the impact of terminal heat stress on various morpho-physiological traits and their association in wheat under control and terminal heat stress condition. The experiment was conducted using thirty-five wheat genotypes in a Randomized Complete Block design (RCBD) plots on three different sowing dates to induce terminal heat stress. A range of 11 morpho-physiological parameters were assessed. All of the traits showed significant variations under studied conditions. Estimates of the genotypic and phenotypic coefficients of variation (GCV and PCV) showed that PCV was higher than GCV indicating large environmental influence on the expression of the traits under study. High GCV and PCV were observed in grain per plant and yield per plant in both normal and heat stress conditions. Chlorophyll content, grain per plant and yield per plant showed highest heritability with high genetic advance (GA) under both normal and terminal heat stress condition. According to the results of the path co-efficient analysis, grain per plant had a strong positive connection with grain yield and plant height and days to 50% flowering had a negative correlation with grain yield per plant under both normal and stress condition. Canopy temperature has direct negative effect on yield in stress condition. The identified traits can be used as effective selection criteria under terminal heat stress condition to develop high yielding heat tolerant wheat variety. [Fundam Appl Agric 2024; 9(2.000): 65-71]

Abstract Background Developing and enriching genetic resources plays important role in the crop improvement. The flag leaf affects plant architecture and contributes to the grain yield of wheat (Triticum aestivum L.). The genetic improvement of flag leaf traits faces problems such as a limited genetic basis. Among the various genetic resources of wheat, Thinopyrum intermedium has been utilized as a valuable resource in genetic improvement due to its disease resistance, large spikes, large leaves, and multiple flowers. In this study, a recombinant inbred line (RIL) population was derived from common wheat Yannong15 and wheat-Th. intermedium introgression line SN304 was used to identify the quantitative trait loci (QTL) for flag leaf-related traits. Results QTL mapping was performed for flag leaf length (FLL), flag leaf width (FLW) and flag leaf area (FLA). A total of 77 QTLs were detected, and among these, 51 QTLs with positive alleles were contributed by SN304. Fourteen major QTLs for flag leaf traits were detected on chromosomes 2B, 3B, 4B, and 2D. Additionally, 28 QTLs and 8 QTLs for flag leaf-related traits were detected in low-phosphorus and drought environments, respectively. Based on major QTLs of positive alleles from SN304, we identified a pair of double-ended anchor primers mapped on chromosome 2B and amplified a specific band of Th. intermedium in SN304. Moreover, there was a major colocated QTL on chromosome 2B, called QFll/Flw/Fla-2B, which was delimited to a physical interval of approximately 2.9 Mb and contained 20 candidate genes. Through gene sequence and expression analysis, four candidate genes associated with flag leaf formation and growth in the QTL interval were identified. Conclusion These results promote the fine mapping of QFll/Flw/Fla-2B, which have pleiotropic effects, and will facilitate the identification of candidate genes for flag leaf-related traits. Additionally, this work provides a theoretical basis for the application of Th. intermedium in wheat breeding.

Abstract Spike length (SL) is one of the most important agronomic traits affecting yield potential and stability in wheat. In this study, a major stable quantitative trait locus (QTL) for SL, i.e., qSl-2B, was detected in multiple environments in a recombinant inbred line (RIL) mapping population, KJ-RILs, derived from a cross between Kenong 9204 (KN9204) and Jing 411 (J411). The qSl-2B QTL was mapped to the 60.06–73.06 Mb region on chromosome 2B and could be identified in multiple mapping populations. An InDel molecular marker in the target region was developed based on a sequence analysis of the two parents. To further clarify the breeding use potential of qSl-2B, we analyzed its genetic effects and breeding selection effect using both the KJ-RIL population and a natural mapping population, which consisted of 316 breeding varieties/advanced lines. The results showed that the qSl-2B alleles from KN9204 showed inconsistent genetic effects on SL in the two mapping populations. Moreover, in the KJ-RILs population, the additive effects analysis of qSl-2B showed that additive effect was higher when both qSl-2D and qSl-5A harbor negative alleles under LN and HN. In China, a moderate selection utilization rate for qSl-2B was found in the Huanghuai winter wheat area and the selective utilization rate for qSl-2B continues to increase. The above findings provided a foundation for the genetic improvement of wheat SL in the future via molecular breeding strategies.

A recombinant inbred line (RIL) population derived from wheat landrace Qingxinmai and breeding line 041133 exhibited segregation in resistance to powdery mildew and stripe rust in five and three field tests, respectively. A 16K genotyping by target sequencing (GBTS) single-nucleotide polymorphism (SNP) array-based genetic linkage map was used to dissect the quantitative trait loci (QTLs) for disease resistance. Four and seven QTLs were identified for adult-plant resistance (APR) against powdery mildew and stripe rust. QPm.caas-1B and QPm.caas-5A on chromosomes 1B and 5A were responsible for the APR against powdery mildew in line 041133. QYr.caas-1B, QYr.caas-3B, QYr.caas-4B, QYr.caas-6B.1, QYr.caas-6B.2, and QYr.caas-7B detected on the five Bgenome chromosomes of line 041133 conferred its APR to stripe rust. QPm.caas-1B and QYr.caas.1B were co-localized with the pleiotropic locus Lr46/Yr29/Sr58/Pm39/Ltn2. A Kompetitive Allele Specific Polymorphic (KASP) marker KASP_1B_668028290 was developed to trace QPm/Yr.caas.1B. Four lines pyramiding six major disease resistance loci, PmQ, Yr041133, QPm/Yr.caas-1B, QPm.caas-2B.1, QYr.caas-3B, and QPm.caas-6B, were developed. They displayed effective resistance against both powdery mildew and stripe rust at the seedling and adult-plant stages. [ABSTRACT FROM AUTHOR]

Plant structure type (PT) is an important complex and quantitative trait to regulating yield potential and stress tolerance in wheat (Triticum aestivum L.). In this study, a recombinant inbred line (RIL) population genotyped by wheat 50 K SNP chip was employed to detect quantitative trait loci (QTL) controlling plant structure type and seed-related eight traits in seven environments. A total of 13 QTL were detected in multiple environments. By comparing previous studies, QKw-5D-2-2 (kernel width) and QSnl-6B (spike neck length), on chromosomes 5D and 6B, respectively, were regarded as two new multi-environmental stable QTLs explaining 5.01–11.51% and 9.79–15.01% of the phenotypic variation, correspondingly. In addition, we predicted two genes associated with grain width in the interval QKw-5D-2-2, and seven multi-environmentally stable QTLs on chromosome 4D were found to be distributed in clusters; significant correlations were found between plant height (PH) and, PT, spike neck length (SNL), basal two internode length (BL), kernel width (KW) and thousand kernel weights (TKW) by genetic and correlation analyses. In summary, our results will provide help to understand the genetic relationship between plant structure type and yield potential. And the newly identified QTLs and QTL clusters lay the genetic foundation for fine localization of plant structure type related traits and molecular marker-assisted breeding in wheat genetic improvement. [ABSTRACT FROM AUTHOR]

Spike length (SL) is one of the most important agronomic traits affecting yield potential and stability in wheat. In this study, a major stable quantitative trait locus (QTL) for SL, i.e., qSl-2B, was detected in multiple environments in a recombinant inbred line (RIL) mapping population, KJ-RILs, derived from a cross between Kenong 9204 (KN9204) and Jing 411 (J411). The qSl-2B QTL was mapped to the 60.06–73.06 Mb region on chromosome 2B and could be identified in multiple mapping populations. An InDel molecular marker in the target region was developed based on a sequence analysis of the two parents. To further clarify the breeding use potential of qSl-2B, we analyzed its genetic effects and breeding selection effect using both the KJ-RIL population and a natural mapping population, which consisted of 316 breeding varieties/advanced lines. The results showed that the qSl-2B alleles from KN9204 showed inconsistent genetic effects on SL in the two mapping populations. Moreover, in the KJ-RILs population, the additive effects analysis of qSl-2B showed that additive effect was higher when both qSl-2D and qSl-5A harbor negative alleles under LN and HN. In China, a moderate selection utilization rate for qSl-2B was found in the Huanghuai winter wheat area and the selective utilization rate for qSl-2B continues to increase. The above findings provided a foundation for the genetic improvement of wheat SL in the future via molecular breeding strategies. Key message: A major stable QTL for spike length was identified in wheat, and its genetic effect on yield related-traits as well as its potential use value in molecular breeding programs were characterized. [ABSTRACT FROM AUTHOR]

Phytotoxic activity of essential oil emulsions (EOEs) of aromatic plants such as Mentha piperita, Pelargonium graveolens, Matricaria chamomilla, Chrysopogon zizanioides, Pogostemon patchouli, Mentha arvensis, and aqueous extracts of Andrographis paniculata were evaluated for problematic weeds like Avena fatua and Phalaris minor, along with wheat (Triticum aestivum) as a test crop through laboratory bioassay studies during 2020–2021. The chemical composition of essential oils was analyzed through GC/GC–MS. Results of the laboratory bioassay revealed that EOEs of M. piperita, C. zizanioides, M. arvensis, and an aqueous extract of A. paniculata as pre-emergence bioherbicides strongly inhibited germination and seedling growth of the tested weed species in a dose dependent manner, with P. minor and A. fatua being selectively more sensitive than T. aestivum. Percent seed germination varied between treatments, ranging from 3.45–48.28%, 3.45–100%, and 4.55–90.91% among T. aestivum, A. fatua, and P. minor, respectively. Based on these results, these four treatments showing the highest phytotoxic activity were further evaluated through a pot culture study. The results showed that treatments with essential oil emulsions and aqueous extracts had a negative impact on seedling Vigor Index I and Vigor Index II. Comparing physiological processes in P. minor, like relative electrolyte leakages, essential oil of M. arvensis at concentration 1% + 8% (pre emergence + early post emergence) had the highest levels of 47.16%, followed by the value of 38.86% which was recorded in C. zizanioides at concentration 1% + 8% (pre emergence + early post emergence) and 22.80% reported in M. piperita at concentration 1% + 8% (pre emergence + early post emergence) treated plants. These levels were higher than those in the untreated control (10.13%). Indeed, at higher concentrations of each treatment, grain yield per plant decreased in the range of 7–29% with respect to the untreated control. The data on phytotoxicity rating showed that visible injury symptoms in T. aestivum plants were less severe as compared to the symptoms recorded in A. fatua and P. minor weeds. This is the first in-depth study to show that emulsions of essential oils from P. graveolens, C. zizanioides, and P. patchouli are phytotoxic. It is also the first time that M. arvensis and C. zizanioides have been shown to be pre-emergence bioherbicides in wheat. Hence, our study presents these EOEs as novel candidates of biological origin that can be used in sustainable weed management, especially in organic farming systems. [ABSTRACT FROM AUTHOR]

The experiment commenced in the crop season of 2021-2022 at two experimental locations--first at the Department of Field Crops, College of Agriculture and Forestry, University of Mosul, Iraq, and the second was at a farmer's field in Dohuk Governorate, Iraq. The presented study assessed the two wheat cultivars (Rasheed and Buhouth1) and their response to different concentrations of bread yeast (0, 4, and 8 g L-1), as the wheat plants incurred spraying with yeast powder. The experimental layout used the randomized complete block design (RCBD) with three replications. According to the results, cultivar Rasheed showed significant superiority for plant height (49.4 and 50.2 cm), spike length (6.9 and 7.3 cm), and spikes plant-1 (5.7 and 6.1 spikes plant-1), and Buhouth1 cultivar was substantially superior for grain yield (18.6 and 20.6 g plant-1) and harvest index (34.77% and 40.26%) for both locations. Also, from the results, the time of adding bread yeast in the booting stage was superior for characteristics: spikes plant-1 (5.9 and 5.7), grain yield (19.1 and 20.9 g plant-1), and harvest index (34.85% and 40.42%), whereas the time of addition in the tillering stage was superior for the 1000- grain weight (36.97 and 36.66 g) and biological yield (58.4 and 56.0 g) for both locations. The bread yeast concentration findings revealed a considerable advantage of the concentrations at 4 and 8 g L-1 (they did not differ significantly from one other) over the absence of bread yeast concentration of 0 g L-1 in the tillers plant-1, spike length, spikes plant-1, and biological yield. In the harvest index %, the concentration above 4 g L-1 was best for the two locations. Most binary and triple interactions of the components in this investigation revealed substantial changes, particularly when their part involved spraying with bread yeast for the two experimental locations. [ABSTRACT FROM AUTHOR]

Agricultural areas worldwide suffer immensely due to the rapid depletion of irrigation water. Applying the proper nutrients can alleviate the harmful effects of water stress. This field study transpired to evaluate the influence of both titanium-dioxide (TiO2) and zinc-oxide (ZnO) nanoparticles on two wheat (Triticum aestivum L.) cultivars (Gimeza-12 and Sids-13) under water irrigation requirements (WIR) of 100% and 75% WIR. Water stress reduced yield attributes and mineral contents but increased protein, gluten, Zeleny sedimentation index, flavonoids, antioxidant activities, and WP. All used concentrations of TiO2-NPs and ZnO-NPs induced positive responses for all tested parameters compared with non-treated corresponding controls under well-watered and drought-stress conditions. Treatment with 10 mg L-1 of ZnO-NPs followed by 10 mg L-1 TiO2-NPs gave the highest values of all studied yield parameters in plants subjected to 75% WIR for both cultivars compared to other controls. The results showed that the Gimeza-12 cultivar, which had the highest grain yield, was more tolerant to drought than the Sids-13 cultivar. [ABSTRACT FROM AUTHOR]

Wheat is a globally dominant staple food and one of the highest-consumed products because of its taste, texture, and bread quality. Genetic variability, heritability, and genetic advancement are essential to learning about the yield potential of crops. Finding out wheat's heritability and genetic advance led to this study's design at the research area of the Department of Plant Breeding and Genetics, the University of Agriculture, Peshawar, in 2021-2022. The experiment began using 27 wheat genotypes comprising nine parents and 18 F3 populations evaluated in a random complete block design (RCBD) with three replications. Highly significant variations observed came from analysis of variance among parents and F3 populations for days to heading, plant height, tillers plant-1, flag leaf area, spikelet's spike-1, the number of grains spike-1, a thousand-grain weight, and biomass yield. The highest heritability estimates of 0.82, 0.87, 0.88, 0.89, 0.86, 0.76, 0.88, 0.86, 0.89, 0.87, 0.86, and 0.84 emerged from Watan x Janbaz, Fakhr-e-Sarhad x AUP-5008, Pirsabak-2005 x AUP-5008, Barsat x Tatara, Fakhr-e- Sarhad x Tatara, Pirsabak-2005 x Tatara, Watan x Tatara, Watan x AUP-5008, AUP-4008 x Janbaz, Barsat x Tatara, Watan x AUP-5008, and Barsat x Janbaz, respectively, for productive traits. The highest values of genetic advance were 32.71, 20.33, 35.08, and 34.24 for Fakhr-e-Sarhad x AUP-5008, Fakhr-e-Sarhad x Janbaz, Pirsabak-2005 x Tatara, and Watan x Tatara, respectively. The parental genotypes Janbaz and AUP-5008 were the most promising genotypes recommended for further evaluation in upcoming breeding schemes. [ABSTRACT FROM AUTHOR]

Members of the abscisic acid (ABA)-responsive element (ABRE) binding factor (ABF) and ABA-responsive element binding protein (AREB) families play essential roles in the regulation of ABA signaling pathway activity and shape the ability of plants to adapt to a range of stressful environmental conditions. To date, however, systematic genome-wide analyses focused on the ABF/AREB gene family in wheat are lacking. Here, we identified 35 ABF/AREB genes in the wheat genome, designated TaABF1–TaABF35 according to their chromosomal distribution. These genes were further classified, based on their phylogenetic relationships, into three groups (A–C), with the TaABF genes in a given group exhibiting similar motifs and similar numbers of introns/exons. Cis-element analyses of the promoter regions upstream of these TaABFs revealed large numbers of ABREs, with the other predominant elements that were identified differing across these three groups. Patterns of TaABF gene expansion were primarily characterized by allopolyploidization and fragment duplication, with purifying selection having played a significant role in the evolution of this gene family. Further expression profiling indicated that the majority of the TaABF genes from groups A and B were highly expressed in various tissues and upregulated following abiotic stress exposure such as drought, low temperature, low nitrogen, etc., while some of the TaABF genes in group C were specifically expressed in grain tissues. Regulatory network analyses revealed that four of the group A TaABFs (TaABF2, TaABF7, TaABF13, and TaABF19) were centrally located in protein–protein interaction networks, with 13 of these TaABF genes being regulated by 11 known miRNAs, which play important roles in abiotic stress resistance such as drought and salt stress. The two primary upstream transcription factor types found to regulate TaABF gene expression were BBR/BPC and ERF, which have previously been reported to be important in the context of plant abiotic stress responses. Together, these results offer insight into the role that the ABF/AREB genes play in the responses of wheat to abiotic stressors, providing a robust foundation for future functional studies of these genes. [ABSTRACT FROM AUTHOR]

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Background and Aims The development and morphology of crop plants have been profoundly altered by evolution under cultivation, initially through unconscious selection, without deliberate foresight, and later by directed breeding. Wild wheats remain an important potential source of variation for modern breeders; however, the sequence and timing of morphological changes during domestication are not fully resolved. Methods We grew and measured 142 wheat accessions representing different stages in wheat evolution, including three independent domestication events, and compared their morphological traits to define the morphospace of each group. Key Results The results show that wild and domesticated wheats have overlapping morphospaces, but each also occupies a distinct area of morphospace from one another. Polyploid formation in wheat increased leaf biomass and seed weight but had its largest effects on tiller loss. Domestication continued to increase the sizes of wheat leaves and seeds and made wheat grow taller, with more erect architecture. Associated changes to the biomass of domesticated wheats generated more grains and achieved higher yields. Landrace improvement subsequently decreased the numbers of tillers and spikes, to focus resource allocation to the main stem, accompanied by a thicker main stem and larger flag leaves. During the Green Revolution, wheat height was reduced to increase the harvest index and therefore yield. Modern wheats also have more erect leaves and larger flower biomass proportions than landraces. Conclusions Quantitative trait history in wheat differs by trait. Some trait values show progressive changes in the same direction (e.g. leaf size, grain weight), whereas others change in a punctuated way at particular stages (e.g. canopy architecture), and other trait values switch directions during wheat evolution (e.g. plant height, flower biomass proportion). Agronomically valued domestication traits arose during different stages of wheat history, such that modern wheats are the product of >10 000 years of morphological evolution. [ABSTRACT FROM AUTHOR]

Osmopriming has been shown to improve the germination and growth of bread wheat (Triticum aestivum L.). This study explores the impact of various priming agent NaCl (3g l-1), proline (1 mM), ZnSO4 (1 mM), and their combination on wheat performance during the summer season (Jul-Aug 2022) at the greenhouse of Payame Noor University, Tabriz. Wheat seeds treated with a combination of priming agent demonstrated significantly enhanced performance compared to untreated seeds. Chlorophyll fluorescence measurements taken 35 days post-cultivation revealed a higher Photosystem Performance Index (PIabs) in osmoprimed seeds, particularly those treated with combined priming agent. Furthermore, primed plants demonstrated elevated concentrations of chlorophyll a, b, and carotenoids. Osmopriming also modulated the oxidative status of enzymes such as glutathione peroxidase (GPX), catalase (CAT), and superoxide dismutase (SOD). Genetic analysis showed that osmopriming could influence the expression of NHX2, a gene linked to improving plant growth, water uptake, and yield in stress conditions.

Abstract Background Wheat, a crucial food crop in China, is highly vulnerable to drought stress throughout its growth and development. WRKY transcription factors (TFs), being one of the largest families of TFs, play a vital role in responding to various abiotic stresses in plants. Results Here, we cloned and characterized the TF TaWRKY31 isolated from wheat. This TF, belonging to the WRKY II family, contains a WRKYGQK amino acid sequence and a C2H2-type zinc finger structure. TaWRKY31 exhibits tissue-specific expression and demonstrates responsiveness to abiotic stresses in wheat. TaWRKY31 protein is localized in the nucleus and can function as a TF with transcription activating activity at the N-terminus. Results showed that the wheat plants with silenced strains (BSMV:TaWRKY31-1as and BSMV:TaWRKY31-2as) exhibited poor growth status and low relative water content when subjected to drought treatment. Moreover, the levels of O2·−, H2O2, and malondialdehyde (MDA) in the BSMV:TaWRKY31-induced wheat plants increased, while the activities of antioxidant enzymes (superoxide dismutase, peroxidase, and catalase) decreased. Compared to control plants, BSMV:TaWRKY31-induced wheat plants exhibited lower expression levels of TaSOD (Fe), TaPOD, TaCAT, TaDREB1, TaP5CS, TaNCED1, TaSnRK2, TaPP2C, and TaPYL5.Under stress or drought treatment conditions, the overexpression of TaWRKY31 in Arabidopsis resulted in decreased levels of H2O2 and MDA, as well as reduced stomatal opening and water loss. Furthermore, an increase in resistance oxidase activity, germination rate, and root length in the TaWRKY31 transgenic Arabidopsis was observed. Lastly, overexpression of TaWRKY31 in Arabidopsis resulted in higher the expression levels of AtNCED3, AtABA2, AtSnRK2.2, AtABI1, AtABF3, AtP5CS1, AtSOD (Cu/Zn), AtPOD, AtCAT, AtRD29A, AtRD29B, and AtDREB2A than in control plants. Conclusions Our findings indicate that TaWRKY31 enhances drought resistance in plants by promoting the scavenging of reactive oxygen species, reducing stomatal opening, and increasing the expression levels of stress-related genes.

Environmental stresses, including drought stress, seriously threaten food security. Previous studies reported that wheat F-box protein, TaFBA1, responds to abiotic stresses in tobacco. Here, we generated transgenic wheat with enhanced (overexpression, OE) or suppressed (RNA interference, RNAi) expression of TaFBA1. The TaFBA1-OE seedlings showed enhanced drought tolerance, as measured by survival rate and fresh weight under severe drought stress, whereas the RNAi plants showed the opposite phenotype. Furthermore, the OE plants had stronger antioxidant capacity compared to WT and RNAi plants and maintained stomatal opening, which resulted in higher water loss under drought stress. However, stronger water absorption capacity in OE roots contributed to higher relative water contents in leaves under drought stress. Moreover, the postponed stomatal closure in OE lines helped to maintain photosynthesis machinery to produce more photoassimilate and ultimately larger seed size. Transcriptomic analyses conducted on WT and OE plants showed that genes involved in antioxidant, fatty acid and lipid metabolism and cellulose synthesis were significantly induced by drought stress in the leaves of OE lines. Together, our studies determined that the F-box protein TaFBA1 modulated drought tolerance and affected yield in wheat and the TaFBA1 gene could provide a desirable target for further breeding of wheat.

Ten wheat varieties, Benazir, Hamal Fakir, TD-I, NIA Sunder, TJ-83, Marvi-2000, NIA Amber, Sarsabz, Kiran-95, and Imdad-05, sown in split-plot design (SPD) with three replications, underwent wellwatered and water-stress influences at the time of anthesis, at the Botanical Garden, Department of Plant Breeding and Genetics, Sindh Agriculture University, Tandojam, during 2022-2023. The observed traits included days to 1st booting, days to 90% heading, days to 90% maturity, peduncle length (cm), plant height (cm), tillers plant-1, spike length (cm), spikelets spike-1, grains spike-1, seed index (1000-grain weight, g), grain yield plant-1 (g), biological yield plant-1 (g), and harvest index (%). Based on drought tolerance indices, the result demonstrated that genotypes, treatments, and genotypes ×treatments significantly affected yield and its contributing traits. The genotypes, such as Imdad-05, NIA Amber, and TD-1, considerably exhibited drought tolerance, whereas Marvi-2000 and Kiran-95 were susceptible. The grain yield expressed positive and significant association toward other traits, such as days to 1st booting, days to 90% heading, days to 90% maturity, peduncle length, plant height, tillers plant-1, spike length, spikelets spike-1, grains spike-1, seed index grain weight, grain yield plant-1, biological yield plant-1, and harvest index. Seven indices calculated grain yield in Yp and Ys appeared significantly and positively associated with the first three components mentioned at about 95.76% of the total variability and directly connected with the STI, GMP, TOL, and MP, namely, Imdad-05, NIA Sunder, and TD-1 considered as highly drought-tolerant; Marvi-2000 and Benazir, as moderately tolerant, and NIA Amber and Kiran-95 were the susceptible ones. [ABSTRACT FROM AUTHOR]

Drought is one of the main environmental factors affecting crop growth, and breeding drought-tolerant cultivars is one of the most economic and effective ways of increasing yields and ensuring sustainable agricultural production under drought stress. To facilitate the breeding of drought-tolerant wheat, this study was conducted to evaluate genotypic differences in the drought tolerance of 334 wheat genotypes collected from China and Australia with the aim of screening for drought-tolerant and -sensitive genotypes and to elucidate the corresponding physiological mechanisms. A hydroponic-air experiment (roots exposed to air for 7 h/d and continued for 6 d) showed significant genotypic differences in shoot and root dry weights among the genotypes. The relative shoot and root dry weights, expressed as the percentage of the control, showed a normal distribution, with variation ranges of 20.2–79.7% and 32.8–135.2%, respectively. The coefficients of variation were in the range of 18.2–22.7%, and the diversity index was between 5.71 and 5.73, indicating a rich genetic diversity among the wheat genotypes for drought tolerance. Using phenotypic differences in relative dry weights in responses to drought stress, 20 of each of the most drought-tolerant and drought-sensitive genotypes were selected; these were further evaluated in pot experiments (watering withheld until the soil moisture content reached four percent). The results showed that the trends in drought tolerance were consistent with the hydroponic-air experiment, with genotypes W147 and W235 being the most drought-tolerant and W201 and W282 the most sensitive. Significant genotypic differences in water use efficiency in response to drought were observed in the pot experiment, with the drought-tolerant genotypes being markedly higher and the two sensitive genotypes being no different from the control. A marked increase in bound water content in the drought stress plants was observed in the two drought-tolerant genotypes, while a decrease occurred in the free water. The reductions in photochemical efficiencies of PSII, transpiration rates, net photosynthesis rates, chlorophyll contents and stomatal conduction in the drought-sensitive genotypes W201 and W282 under drought stress were higher than the two tolerant genotypes. This study provides a theoretical guide and germplasm for the further genetic improvement of drought tolerance in wheat. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) is one of the major cereal grain crops and losses grain yield exceeds over 60% due to salinity stress. Now, it is imperative to develop a comprehensive understanding of salt tolerance contrivances and the assortment of reliable tolerance indices is crucial for breeding salt-tolerant wheat cultivars. The mapping of reliable quantitative trait loci (QTLs) and better understanding of the physiological and molecular basis of salt tolerance have revealed new horizons for the development of salt-tolerant wheat cultivars. From the studies carried out in bread wheat, we have summarized the various information such as screening methods, evaluation parameters, key genomic regions (harboring QTLs/QTNs) and salt responsive candidate genes demarcated through bi-parental and genome wide association mapping strategies. The highly consistent QTLs were for plant height, grain yield, thousand grain weight, Na+ and K+ that should be validated using molecular techniques. We hope this review will serve as an important reference guide for scientific community as well as wheat breeders to select the QTLs for MAS to improve the wheat genotypes for salinity tolerance. [ABSTRACT FROM AUTHOR]

Glutaredoxins (GRXs) are small-molecular-weight proteins present in a wide range of organisms, and they play a key role in maintaining the redox homeostasis of cells. Most studies on GRXs are conducted in animals and humans, and those conducted on plants are scarce. The number and types of GRX genes vary in different plants. According to the active sites, the GRX family can be further divided into the CPYC, CGFS, and CC subfamilies. The CPYC and CGFS subfamilies are present in eukaryotes. The CC subfamily is exclusively present in higher plants and has the highest number of genes. In this study, 85 GRX genes were identified in common wheat (Triticum aestivum L.) using a bioinformatic method, wherein 12, 9, and 64 belonged to the CPYC, CGFS, and CC subfamilies, respectively. All TaGRX genes were homogeneously distributed in the three subgenomes of wheat. The gene structure analysis revealed that TaGRX members had 1–7 introns. The conserved motif analysis revealed that members of the same TaGRX subfamily had similar motifs. An analysis of cis-regulatory elements of promoters demonstrated that most TaGRX members had auxin-responsive elements; cis-regulatory elements, such as methyl jasmonate (MeJA), MYB, and abscisic acid (ABA), were distributed in all subfamilies, and the cell-cycle regulation element was only observed in the CC and CPYC subfamily members. Additionally, the synteny of the GRX genes in wheat, in wheat and Arabidopsis, and in wheat and barley was analyzed to clarify the evolutionary correlation of TaGRXs. The expression characteristics of TaGRXs were investigated, and TaGRX expression in various tissues and its responses to different abiotic stresses were preliminarily determined. This study provides a reference for the functional analysis of TaGRXs and understanding their role in molecular breeding of wheat. [ABSTRACT FROM AUTHOR]

Low temperature and cold damage are natural factors that seriously reduce wheat yield. Thus, how to improve the cold resistance of wheat has been the focus of wheat breeders and geneticists. However, the genetic improvement for this trait has been slow, mainly because cold resistance is a complex quantitative trait and field phenotypic identification is relatively difficult. Therefore, the discovery, mapping, and cloning of the cold resistance genes of wheat provide a theoretical basis for the genetic improvement of wheat against cold resistance and facilitate the analysis of the molecular mechanisms of cold resistance in wheat. This study used the wheat line H261 and its EMS mutants LF2099 and XiNong 239 as materials. Cold trait segregation occurred in the F2 generation of mutants LF2099 and XiNong 239 at a 15:1 separation ratio. Genetic analysis showed that two dominant overlapping genes, temporarily named Wcr-3 and Wcr-4, control cold resistance in wheat. Furthermore, a combined BSA and SNP array established that Wcr-3 is between BU100519 (SSR marker) and AX-94843669 (SNP marker). The markers are 1.32 cM apart, corresponding to the 5.41 Mb physical interval on the Chinese Spring 2B chromosome with 67 functionally annotated genes. Wcr-4 is located between AX-94657955 (SNP marker) and LC-23 (SSR marker), which are 1.79 cM apart, corresponding to a 2.35 Mb physical interval on the Chinese Spring 2D chromosome, which contains 66 functionally annotated genes. Wcr-3 and Wcr-4 are two new cold resistance genes, laying the foundation for their fine mapping and cloning. [ABSTRACT FROM AUTHOR]

A recombinant inbred line (RIL) population derived from wheat landrace Qingxinmai and breeding line 041133 exhibited segregation in resistance to powdery mildew and stripe rust in five and three field tests, respectively. A 16K genotyping by target sequencing (GBTS) single-nucleotide polymorphism (SNP) array-based genetic linkage map was used to dissect the quantitative trait loci (QTLs) for disease resistance. Four and seven QTLs were identified for adult-plant resistance (APR) against powdery mildew and stripe rust. QPm.caas-1B and QPm.caas-5A on chromosomes 1B and 5A were responsible for the APR against powdery mildew in line 041133. QYr.caas-1B, QYr.caas-3B, QYr.caas-4B, QYr.caas-6B.1, QYr.caas-6B.2, and QYr.caas-7B detected on the five B-genome chromosomes of line 041133 conferred its APR to stripe rust. QPm.caas-1B and QYr.caas.1B were co-localized with the pleiotropic locus Lr46/Yr29/Sr58/Pm39/Ltn2. A Kompetitive Allele Specific Polymorphic (KASP) marker KASP_1B_668028290 was developed to trace QPm/Yr.caas.1B. Four lines pyramiding six major disease resistance loci, PmQ, Yr041133, QPm/Yr.caas-1B, QPm.caas-2B.1, QYr.caas-3B, and QPm.caas-6B, were developed. They displayed effective resistance against both powdery mildew and stripe rust at the seedling and adult-plant stages.

Drought is a misfortune for crops. Wheat is a staple crop and its sustainability and adequate supply are vital to food security around the world. The development of drought-tolerant cultivars in wheat is a major challenge to breeders, therefore there is dire need of time to determine the genetic components of drought tolerance in wheat crop. To overcome intense drought stress, wheat plants undergo certain morphological and physiological changes and develop certain genetically adaptive mechanisms. Since wheat is an allotriploid with three sub-genomes, its adaptability molecular mechanisms to drought, particularly needs scientific attention. Here, we systematically and comprehensively reviewed the causes of wheat drought tolerance and the consequences for wheat physiology and genetics. The quantitative trait loci (QTL), which be function on the control of wheat drought tolerance, were comprehensively summarized by a meta-analysis and total 75 meta-QTLs (MQTLs) were identified. In addition, we summarized the genes tightly involved in wheat drought tolerance, and several important genes were selected to elucidate signaling networks related to the wheat drought tolerance. This review is integral to growing suitable strains in the worldwide arid regions to improve wheat yields under recent global climate change scenarios.

Abstract Background Vernalization, as a vital process in the life cycle of winter cereal, has important effects on floral organ formation and flowering time. Many morphological changes together with molecular changes occur during the vernalization period. Here, we used transcriptome sequencing to analyze the transcriptomic changes in wheat leaves before, during and after vernalization using the winter wheat cultivar ‘Shiluan02-1’. Results A total of 16,370 differentially expressed genes were obtained across different vernalization periods. Gene Ontology enrichment analysis revealed that photoperiodism, photoprotection, photosynthesis, lipid transport and biosynthetic process, and chlorophyll metabolic process were closely related to vernalization. In addition, AP2/ERF, C2H2, bHLH, WRKY, MYB, MYB-related, and NAC transcription factors were significantly enriched during vernalization, and the transcription factor expression patterns suggested the intricate regulation of transcription factor modules in plant vernalization pathways. Analysis of gene expression patterns of the MADS-box transcription factor genes showed different expression patterns during vernalization phases, among which VERNALIZATION1 (VRN1) genes were found to gradually increase during vernalization periods from V0 to V35, while decline in the V42 phase, then increase after vernalization. The Tavrt-2 gene cooperated with Tavrn1 to regulate flowering induced by vernalization, and its expression level was rapidly increased by vernalization but declined in the V42 phase and then increased after vernalization. Some genes from the ICE-CBF-COR pathway were also identified, and additional analysis indicated that some key genes related to phytohormone biosynthesis and signal transduction were enriched during the vernalization period, such as gibberellic acid, ethylene, abscisic acid and jasmonic acid biosynthesis and signaling pathway genes. Conclusions Our study provides valuable molecular information for future studies on wheat vernalization regulation and also serves as an excellent reference for future wheat breeding.

SUMMARY: Field‐grown crops rarely experience growth conditions in which yield can be maximized. Environmental stresses occur in combination, with advancements in crop tolerance further complicated by its polygenic nature. Strategic targeting of causal genes is required to meet future crop production needs. Here, we employed a systems biology approach in wheat (Triticum aestivum L.) to investigate physio‐metabolic adjustments and transcriptome reprogramming involved in acclimations to heat, drought, salinity and all combinations therein. A significant shift in magnitude and complexity of plant response was evident across stress scenarios based on the agronomic losses, increased proline concentrations and 8.7‐fold increase in unique differentially expressed transcripts (DETs) observed under the triple stress condition. Transcriptome data from all stress treatments were assembled into an online, open access eFP browser for visualizing gene expression during abiotic stress. Weighted gene co‐expression network analysis revealed 152 hub genes of which 32% contained the ethylene‐responsive element binding factor‐associated amphiphilic repression (EAR) transcriptional repression motif. Cross‐referencing against the 31 DETs common to all stress treatments isolated TaWRKY33 as a leading candidate for greater plant tolerance to combinatorial stresses. Integration of our findings with available literature on gene functional characterization allowed us to further suggest flexible gene combinations for future adaptive gene stacking in wheat. Our approach demonstrates the strength of robust multi‐omics‐based data resources for gene discovery in complex environmental conditions. Accessibility of such datasets will promote cross‐validation of candidate genes across studies and aid in accelerating causal gene validation for crop resiliency. Significance Statement: Using a systems biology approach, the study investigated the response of wheat (Triticum aestivum L.) to different environmental stresses, revealing significant changes in plant response, particularly under single, double and triple stress conditions. The study identified 152 hub genes, with TaWRKY33 as a leading candidate for enhancing plant tolerance to combinatorial stresses. The findings suggest flexible gene combinations for adaptive gene stacking in wheat and demonstrate the usefulness of multi‐omics data resources for gene discovery in complex environmental conditions. [ABSTRACT FROM AUTHOR]

To study the evolution of wheat traits and genetic diversity in southern Huang-Huai winter wheat region, the wheat varieties in the recent 20 years in southern Huang-Huai winter wheat region were as materials. The evolution of wheat traits and genetic diversity were explored from a new perspective by using Shannon-Wiener diversity index (H') and coefficient of variation analysis, fitting trend line after dimensionless traits, principal component analysis, comprehensive score (D' value) evaluation, regression model construction and other methods. The indexes used for the evaluation of wheat varieties in southern Huang-Huai winter wheat region and the germplasm with excellent performance were screened. The results showed that a total of 443 wheat varieties were bred in southern Huang-Huai winter wheat region from 2003 to 2022, and it could be divided into 3 stages based on the number of bred varieties: basic stable stage (from 2003 to 2017), temporary high stage after obvious uplift (from 2018 to 2019, and blowout eruption stage (from 2020 to present ). In recent 20 years, plant height of wheat in southern Huang-Huai winter wheat region decreased slowly with time-going; water absorption remained unchanged; spike number, grain number per spike, 1 000-grain weight, yield, basic seedlings, test weight, protein content, wet gluten content and stability time showed upward trend, among which 1 000-grain weight, yield, basic seedlings, test weight and wet gluten content had relatively strong upward trend. The increase of yield was mainly due to the increase of 1 000-grain weight. The proportion of high-quality special wheat (strong gluten wheat, medium strong gluten wheat, weak gluten wheat) increased in recent years, mainly due to the increase in the proportion of medium strong gluten wheat. The proportion of strong gluten wheat has not increased significantly, which was mainly limited by water absorption and stability time. The dispersion degree and evolution trend of agronomic traits and quality traits were quite different, but their genetic diversity was constantly improving with the year, and genetic stability should be further strengthened. The results of regression model construction showed that 5 traits could be used as the evaluation indexes of the comprehensive performance of wheat in southern Huanghuai winter wheat region, including spike number, yield, test weight, protein content and water absorption. Among 443 varieties, 'Jimai 336' 'Anke 1801' 'Jimai 44' Gushenmai 19' and 'Huawei 305, which had higher D', performed well and could be used as excellent germplasm resources in the breeding of strong gluten wheat. In the future, the breeders should strengthen breeding new varieties with high-quality special wheat, especially weak gluten wheat, and enhance the protection and utilization of germplasm resources. [ABSTRACT FROM AUTHOR]

Introduction: Cytoplasmic male sterility (CMS) is an important tool for hybrid heterosis utilization. However, the underlying mechanisms still need to be discovered. An adequate supply of nutrients is necessary for anther development; pollen abortion would occur if the metabolism of carbohydrates were hampered. Methods: In order to better understand the relationship between carbohydrate metabolism disorder and pollen abortion in S-CMS wheat, the submicroscopic structure of wheat anthers was observed using light microscopy and transmission electron microscopy; chloroplast proteome changes were explored by comparative proteomic analysis; sugar measuring and enzyme assays were performed; and the expression patterns of carbohydrate metabolism-related genes were studied using quantitative real-time PCR (qRT-PCR) method. Results: These results indicated that the anther and microspore in S-CMS wheat underwent serious structural damage, including premature tapetum degeneration, nutritional shortage, pollen wall defects, and pollen grain malformations. Furthermore, the number of chloroplasts in the anthers of S-CMS lines decreased significantly, causing abnormal carbohydrate metabolism, and disintegration of osmiophilic granules and thylakoids. Meanwhile, some proteins participating in the Calvin cycle and carbohydrate metabolism were abnormally expressed in the chloroplasts of the S-CMS lines, which might lead to chloroplast dysfunction. Additionally, several key enzymes and genes related to carbohydrate metabolism were significantly inhibited in S-CMS. Discussion: Based on these results, we proposed a carbohydrate metabolism pathway for anther abortion in S-type cytoplasmic male sterility, which would encourage further exploration of the pollen abortion mechanisms for CMS wheat. [ABSTRACT FROM AUTHOR]

Low phosphorus (LP) stress leads to a significant reduction in wheat yield, primarily in the reduction of biomass, the number of tillers and spike grains, the delay in heading and flowering, and the inhibition of starch synthesis and grouting. However, the differences in regulatory pathway responses to low phosphorus stress among different wheat genotypes are still largely unknown. In this study, metabolome and transcriptome analyses of G28 (LP-tolerant) and L143 (LP-sensitive) wheat varieties after 72 h of normal phosphorus (CK) and LP stress were performed. A total of 181 and 163 differentially accumulated metabolites (DAMs) were detected for G28CK vs. G28LP and L143CK vs. L143LP, respectively. Notably, the expression of pilocarpine (C07474) in G28CK vs. G28LP was significantly downregulated 4.77-fold, while the expression of neochlorogenic acid (C17147) in L143CK vs. L143LP was significantly upregulated 2.34-fold. A total of 4023 differentially expressed genes (DEGs) were acquired between G28 and L143, of which 1120 DEGs were considered as the core DEGs of LP tolerance of wheat after LP treatment. The integration of metabolomics and transcriptomic data further revealed that the LP tolerance of wheat was closely related to 15 metabolites and 18 key genes in the sugar and amino acid metabolism pathway. The oxidative phosphorylation pathway was enriched to four ATPases, two cytochrome c reductase genes, and fumaric acid under LP treatment. Moreover, PHT1;1, TFs (ARFA, WRKY40, MYB4, MYB85), and IAA20 genes were related to the Pi starvation stress of wheat roots. Therefore, the differences in LP tolerance of different wheat varieties were related to energy metabolism, amino acid metabolism, phytohormones, and PHT proteins, and precisely regulated by the levels of various molecular pathways to adapt to Pi starvation stress. Taken together, this study may help to reveal the complex regulatory process of wheat adaptation to Pi starvation and provide new genetic clues for further study on improving plant Pi utilization efficiency. [ABSTRACT FROM AUTHOR]

The paper reports a study conducted with the goal of expanding the possibilities of using the previously obtained multiple nonlinear regression equation describing the dependence of protein content in wheat grain (Y, %) on the amount of crude gluten (X1, %) and 1000-grain weight (X2, g). It has been demonstrated that the original and three improved equations can be used in breeding practice to predict wheat grain protein content. The algorithm and the results of testing the predictive ability and prediction accuracy of the equations using independent data were presented. Analysis of the experimental data from 288 Russian and foreign publications, with a total number of observations n = 4604, obtained for more than 300 winter and spring soft and durum wheats in Russia and abroad (Albania, Belarus, Bulgaria, Egypt, Kazakhstan, Lithuania, Poland, Slovakia, and Ukraine) within the period from 1959 to 2020 showed that 755 observations, or 16.4%, fell beyond the variation limits accepted by GOST 10846-91: Method of Protein Determination. At the same time, the accuracy of protein content prediction reached 83.6%. The developed equations can be used for predicting protein content in almost all cases when the results of protein and crude gluten content analysis in wheat grain, as well as 1000-grain weight, are provided for actual or fixed moisture content or are recalculated for absolute dry matter. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) is regarded as an important staple food crop globally and is sensitive to high temperature (HT) during reproductive stages in comparison to vegetative stages. High-temperature stress is a major abiotic constraint and is projected to reduce crop yield there by threatening food security. A field investigation entitled "Effect of high-temperature stress on yield of various wheat varieties at different growth stages" was conducted at the Students Instructional Farm of the Acharya Narendra Deva University of Agriculture and Technology Kumarganj, Ayodhya (UP) during Rabi season of 2021-22. The experiment was planned under SPD (Split plot Design) with three replications and treatment consisting of three dates of sowing viz; D1 (15th November), D2 (30th November), and D3 (15th December). Results indicated that growth attributes such as plant height, number of tillers plant-1, dry matter plant-1, and membrane stability index were significantly affected by the date of sowing. When late sown variety was planted timely all the growth attributes showed a drastic reduction with respect to late sowing (15th December) However, V1 and V2 showed comparatively good performance in terms of growth attributes when sown early D1 and D2. Performance of V3 was very good as compared to V1 and V2 when sown delayed D3 i.e. facing high temperature stress. Time of sowing decreased substantially almost in all the yield components measured viz; the number of ear bearing tillers-1, number of grains ear-1, ear length (cm), grain yield plant-1 (gm), biological yield plant-1 (g), and test weight (g) and harvest index which caused severe reduction of yield in V1 and V2. Overall growth attributes physiological traits and yield, as well as yield components of the wheat crop, was adversely affected by the time of sowing due to the onset of high temperature during crop growth and particularly grain filling. Variety i.e., V3 (Kundan) reduced the detrimental effect of heat stress by improving physiological traits which ultimately helped in obtaining higher yield. [ABSTRACT FROM AUTHOR]

Multiple genetic factors control tillering, a key agronomy trait for wheat (Triticum aestivum L.) yield. Previously, we reported a dwarf-monoculm mutant (dmc) derived from wheat cultivar Guomai 301, and found that the contents of gibberellic acid 3 (GA3) in the tiller primordia of dmc were significantly higher. Transcriptome analysis indicated that some wheat gibberellin oxidase (TaGAox) genes TaGA20ox-A2, TaGA20ox-B2, TaGA3ox-A2, TaGA20ox-A4, TaGA2ox-A10 and TaGA2ox-B10 were differentially expressed in dmc. Therefore, this study systematically analyzed the roles of gibberellin oxidase genes during wheat tillering. A total of 63 TaGAox genes were identified by whole genome analysis. The TaGAoxs were clustered to four subfamilies, GA20oxs, GA2oxs, GA3oxs and GA7oxs, including seven subgroups based on their protein structures. The promoter regions of TaGAox genes contain a large number of cis-acting elements closely related to hormone, plant growth and development, light, and abiotic stress responses. Segmental duplication events played a major role in TaGAoxs expansion. Compared to Arabidopsis, the gene collinearity degrees of the GAoxs were significantly higher among wheat, rice and maize. TaGAox genes showed tissue-specific expression patterns. The expressions of TaGAox genes (TaGA20ox-B2, TaGA7ox-A1, TaGA2ox10 and TaGA3ox-A2) were significantly affected by exogenous GA3 applications, which also significantly promoted tillering of Guomai 301, but didn't promote dmc. TaGA7ox-A1 overexpression transgenic wheat lines were obtained by Agrobacterium mediated transformation. Genomic PCR and first-generation sequencing demonstrated that the gene was integrated into the wheat genome. Association analysis of TaGA7ox-A1 expression level and tiller number per plant demonstrated that the tillering capacities of some TaGA7ox-A1 transgenic lines were increased. These data demonstrated that some TaGAoxs as well as GA signaling were involved in regulating wheat tillering, but the GA signaling pathway was disturbed in dmc. This study provided valuable clues for functional characterization of GAox genes in wheat. [ABSTRACT FROM AUTHOR]