Winter Wheat Cultivars Research Articles

Delayed Sowing Can Improve Potassium Utilization Efficiency and Grain Potassium Concentration in Winter Wheat

Economic consumption and environmental impacts due to potassium (K) inputs in agriculture are gaining increasing attention. It is urgent to improve K use efficiency (KUE) for agricultural development. Delayed sowing has been shown to maintain grain yield in winter wheat. Still, there needs to be more information regarding the effect of sowing date on crop K status evaluated by the K nutrition index (KNI), KUE, K uptake efficiency (UPE), K utilization efficiency (UTE), and grain K concentration (GKC). Here, we assessed Shannong23 and Tainong18 winter wheat cultivars with three sowing date treatments composed of 26 September (early sowing), 8 October (normal sowing), and 22 October (late sowing) in the 2021–2022 and 2022–2023 growing seasons. The influences of sowing date on the KNI, tillering, grain yield formation, KUE, UPE, UTE, K transport, and GKC were examined. Our study indicated that late sowing in winter wheat was an almost optimal K nutritional situation, whereas early and normal sowing were under situations of excess K. As sowing was delayed, aboveground K uptake (AGK), UPE, and spike number per unit area decreased; UTE and grain number per spike increased; and grain yield and KUE were unchanged. A positive correlation between KNI and UPE and spike number per unit area and a negative correlation between KNI and UTE and grain number per spike were found, whereas no significant correlation between KNI and KUE was observed. Late sowing promoted K transport from pre-anthesis accumulation in vegetative organs to grain, resulting in a higher GKC, which could lead to high grain quality and K recovery. Therefore, late sowing winter wheat can use K more efficiently and increase GKC, implying that delayed sowing can reduce K input, favoring sustainable agriculture development.

Water Use Strategies and Shoot and Root Traits of High-Yielding Winter Wheat Cultivars under Different Water Supply Conditions

Drought is the most important factor limiting winter wheat yield in the North China Plain (NCP). Choosing high-yielding cultivars is an important measure to minimize the negative effects of drought stress. Field studies were conducted with 10 cultivars in the 2020–2022 seasons under three irrigation treatments (I0, without irrigation; I1, irrigated at jointing stage; I2, irrigated at jointing and anthesis stages) in the NCP to examine the water use strategies and root and shoot traits of high-yielding cultivars under different water supply conditions. The results showed that yield variation among cultivars was 21.2–24.6%, 23.7–25.9% and 11.6–15.3% for the I0, I1 and I2 treatments, respectively. Under water deficit conditions (I0 and I1), high-yielding cultivars reduced water use during vegetative stages and increased soil water use during reproductive stages, especially water use from deeper soil layers. Those cultivars with higher root length density (RLD) in deep soil layers exhibited higher water uptake. Each additional millimeter of water used after anthesis from the 100–200 cm soil layers increased grain yield by 23.6–29.6 kg/ha and 16.4–28.5 kg/ha under I0 and I1, respectively. This water use strategy enhanced dry matter accumulation after anthesis, decreased canopy temperature (CT) and increased relative leaf water contents (RLWC), which ultimately improved grain yield. For winter wheat grown under I2, cultivars that decreased water use after anthesis had higher water productivity (WP). Root length (RL), root weight (RW) and root:shoot ratio were each negatively correlated with grain yield, while above-ground biomass was positively correlated with grain yield. Therefore, higher dry matter accumulation and smaller root systems are two important traits of high-yielding cultivars under sufficient water supply conditions (I2) in the NCP.

Identification of Plant and Soil Characteristics Affecting Stability of Winter Wheat Cultivar in Temperate Climates

This study examines the significant variability in grain yield, thousand-grain weight, protein content, sedimentation value, and falling number among winter wheat cultivars across diverse trial locations, elucidating the profound influence of environmental factors on these traits. Employing Shukla’s stability variance and a multi-trait stability index (MTSI), cultivar stability is comprehensively assessed across multiple traits. Cultivars are ranked based on stability variance and cumulative ranking across all traits, with Bataja emerging as the most stable cultivar according to Shukla variance, while Apostel exhibits the lowest stability. Contrarily, MTSI rankings reveal distinct top performers, such as Medalistika and KWS Spencer. Canonical correspondence analysis (CCA) is utilized to discern relationships between stability and genotype characteristics, as well as trait values and soil properties/weather conditions. These findings contribute to the recommendation of stable cultivars for breeding programs and the optimization of crop management practices. Furthermore, this study underscores the need to explore causal relationships between accompanying variables, facilitating informed recommendations for plant breeders and advancing breeding progress amidst a changing climate. The use of multivariate statistical methods, including CCA, enhances our understanding of cultivar traits and stability, offering valuable insights for sustainable agriculture.

A Combination of Resistance Genes Confers High and Durable Resistance Against Stripe Rust in Wheat Cultivar Lantian 26.

'Lantian 26', a leading elite winter wheat cultivar in Gansu Province since its release in 2010, exhibits high resistance or immunization to stripe rust in the adult-plant stage under a high disease pressure in Longnan (southeastern Gansu). Identifying the resistance genes in 'Lantian 26' could provide a basis for enhanced durability and high levels of resistance in wheat cultivars. Here, a segregating population was developed from a cross between a highly susceptible wheat cultivar Mingxian 169 and the highly stripe rust-resistant 'Lantian 26'. The F2 and F2:3 progenies of the cross were inoculated with multiple prevalent virulent races of stripe rust for adult-plant-stage-resistance evaluation in two different environments. Exon sequence alignment analysis revealed that a stripe rust resistance gene on the 718.4- to 721.2-Mb region of chromosome 7BL, tentatively named as YrLT26, and a cosegregation sequence-tagged site (STS) marker GY17 was developed and validated using the F2:3 population and 103 wheat cultivars. The other two resistance genes, Yr9 and Yr30, were also identified in 'Lantian 26' using molecular markers. Therefore, the key to high and durable resistance to stripe rust at the adult stage is the combination of Yr9, Yr30, and YrLT26 genes in 'Lantian 26'. This could be a considerable strategy for improving the wheat cultivars with effective and durable resistance in the high-pressure region for stripe rust.

A tale of two eras: assessing the impact of breeding programs on historical and modern German wheat cultivars under distinct management

Breeding advancements have significantly improved grain yield over recent decades, yet further progress is needed to meet global food demands amid a growing population. In this study, we systematically examine the responses of both historical and modern winter wheat cultivars, released between 1895 and 2007 in Germany, to varying management intensities. We quantified the independent contributions of nitrogen (N) levels, growth regulators, and plant protection measures to crop productivity and growth variables over two growing seasons. Historical cultivars (pre-1960) exhibited a lower yield (4.6 t ha−1) and harvest index (0.30) compared to modern cultivars (post-1960), which demonstrated a higher yield (6.8 t ha−1) and harvest index (0.40) across all treatments, even those excluding both nitrogen and agrochemicals. We found positive trends in the yield and yield components for both historical (1895–1960) and modern (1961–2007) cultivars; however, significance was only noted for modern cultivars. Crop growth in historical cultivars was aided more by growth regulators, while modern cultivars gained more benefits from plant protection. However, both categories of cultivars produced a synergistic response when combining agronomic practices. Based on a comparison of N application rates and agronomic practices, N had a distinctly greater impact on yield and yield components than other treatments. In both historical and modern cultivars, grain number per ear was the most influential contributing factor to yield. Nevertheless, the effect of the thousand grain weight on yield was notably less for modern cultivars compared to their historical ones. Grain nitrogen yield increased up to mid-supply nitrogen application but remained constant at high rates. Results underscored that cultivar-specific responses for yield and yield components need to consider the interactions between fertilization and other agronomic practices.

Genome-wide QTL mapping for agronomic traits in the winter wheat cultivar Pindong 34 based on 90K SNP array.

Agronomic traits are key components of wheat yield. Exploitation of the major underlying quantitative trait loci (QTLs) can improve the yield potential in wheat breeding. In this study, we constructed a recombinant inbred line (RIL) population from Mingxian 169 (MX169) and Pindong 34 (PD34) to determine the QTLs for grain length (GL), grain width (GW), grain length-to-width ratio (LWR), plant height (PH), spike length (SL), grain number per spike (GNS), and the thousand grain weight (TGW) across four environments using wheat 90K SNP array. A QTL associated with TGW, i.e., QTGWpd.swust-6BS, was identified on chromosome 6B, which explained approximately 14.1%-16.2% of the phenotypic variation. In addition, eight QTLs associated with GL were detected across six chromosomes in four different test environments. These were QGLpd.swust-1BL, QGLpd.swust-2BL, QGLpd.swust-3BL.1, QGLpd.swust-3BL.2, QGLpd.swust-5DL, QGLpd.swust-6AL, QGLpd.swust-6DL.1, and QGLpd.swust-6DL.2. They accounted for 9.0%-21.3% of the phenotypic variation. Two QTLs, namely, QGWpd.swust-3BS and QGWpd.swust-6DL, were detected for GW on chromosomes 3B and 6D, respectively. These QTLs explained 12.8%-14.6% and 10.8%-15.2% of the phenotypic variation, respectively. In addition, two QTLs, i.e., QLWRpd.swust-7AS.1 and QLWRpd.swust-7AS.2, were detected on chromosome 7A for the grain LWR, which explained 10.9%-11.6% and 11.6%-11.2% of the phenotypic variation, respectively. Another QTL, named QGNSpd-swust-6DS, was discovered on chromosome 6D, which determines the GNS and which accounted for 11.4%-13.8% of the phenotypic variation. Furthermore, five QTLs associated with PH were mapped on chromosomes 2D, 3A, 5A, 6B, and 7B. These QTLs were QPHpd.swust-2DL, QPHpd.swust-3AL, QPHpd.swust-5AL, QPHpd.swust-6BL, and QPHpd.swust-7BS, which accounted for 11.3%-19.3% of the phenotypic variation. Lastly, a QTL named QSLpd.swust-3AL, conferring SL, was detected on chromosome 3A and explained 16.1%-17.6% of the phenotypic variation. All of these QTLs were defined within the physical interval of the Chinese spring reference genome. The findings of this study have significant implications for the development of fine genetic maps, for genomic breeding, and for marker-assisted selection to enhance wheat grain yield.

Diallel Analysis of Wheat Resistance to Fusarium Head Blight and Mycotoxin Accumulation under Conditions of Artificial Inoculation and Natural Infection.

Breeding resistant wheat cultivars to Fusarium head blight (FHB), caused by Fusarium spp., is the best method for controlling the disease. The aim of this study was to estimate general combining ability (GCA) and specific combining ability (SCA) for FHB resistance in a set of eight genetically diverse winter wheat cultivars to identify potential donors of FHB resistance for crossing. FHB resistance of parents and F1 crosses produced by the half diallel scheme was evaluated under the conditions of artificial inoculation with F. graminearum and natural infection. Four FHB related traits were assessed: visual rating index (VRI), Fusarium damaged kernels (FDK), and deoxynivalenol and zearalenone content in the harvested grain samples. Significant GCA effects for FHB resistance were observed for the parental cultivars with high FHB resistance for all studied FHB resistance related traits. The significant SCA and mid-parent heterosis effects for FHB resistance were rare under both artificial inoculation and natural infection conditions and involved crosses between parents with low FHB resistance. A significant negative correlation between grain yield under natural conditions and VRI (r = -0.43) and FDK (r = -0.47) under conditions of artificial inoculation was observed in the set of the studied F1 crosses. Some crosses showed high yield and high FHB resistance, indicating that breeding of FHB resistant genotypes could be performed without yield penalty. These crosses involved resistant cultivars with significant GCA effects for FHB resistance indicating that that they could be used as good donors of FHB resistance.

Transcriptomic and Metabolomic Analyses Reveal the Response to Short-Term Drought Stress in Bread Wheat (Triticum aestivum L.)

Drought stress, a major abiotic stress, significantly affects wheat (Triticum aestivum L.) production globally. To identify genes and metabolic pathways crucial for responding to short-term drought stress, we conducted transcriptomic and metabolomic analyses of winter wheat cultivar Jimai 418 at four developmental stages: jointing (GS31), booting (GS45), anthesis (GS65), and 8 days after anthesis (DAA8). Transcriptomic analysis identified 14,232 differentially expressed genes (DEGs) under drought stress compared to the control. Specifically, 1387, 4573, 7380, and 892 DEGs were identified at the four developmental stages, respectively. Enriched pathways associated with these DEGs included plant hormone signal transduction, mitogen-activated protein kinase (MAPK) signaling, galactose metabolism, and starch and sucrose metabolism. Totals of 222, 633, 358, and 38 differentially accumulated metabolites (DAMs) were identified at the four stages, respectively. Correlation analysis of both datasets revealed DEGs and DAMs associated with plant hormone signal transduction, arginine and proline metabolism, ABC transporters, and amino acid biosynthesis. These findings offer significant insights into Jimai 418’s molecular response to short-term drought stress. The identified DEGs, DAMs, and enriched pathways contribute to our understanding of wheat drought tolerance. This research will facilitate further investigations into drought tolerance mechanisms and guide the breeding of wheat varieties with enhanced drought resistance.

A new winter wheat genetic resource harbors untapped diversity from synthetic hexaploid wheat

Key messageThe NIAB_WW_SHW_NAM population, a large nested association mapping panel, is a useful resource for mapping QTL from synthetic hexaploid wheat that can improve modern elite wheat cultivars.The allelic richness harbored in progenitors of hexaploid bread wheat (Triticum aestivum L.) is a useful resource for addressing the genetic diversity bottleneck in modern cultivars. Synthetic hexaploid wheat (SHW) is created through resynthesis of the hybridisation events between the tetraploid (Triticum turgidum subsp. durum Desf.) and diploid (Aegilops tauschii Coss.) bread wheat progenitors. We developed a large and diverse winter wheat nested association mapping (NAM) population (termed the NIAB_WW_SHW_NAM) consisting of 3241 genotypes derived from 54 nested back-cross 1 (BC1) populations, each formed via back-crossing a different primary SHW into the UK winter wheat cultivar ‘Robigus’. The primary SHW lines were created using 15 T. durum donors and 47 Ae. tauschii accessions that spanned the lineages and geographical range of the species. Primary SHW parents were typically earlier flowering, taller and showed better resistance to yellow rust infection (Yr) than ‘Robigus’. The NIAB_WW_SHW_NAM population was genotyped using a single nucleotide polymorphism (SNP) array and 27 quantitative trait loci (QTLs) were detected for flowering time, plant height and Yr resistance. Across multiple field trials, a QTL for Yr resistance was found on chromosome 4D that corresponded to the Yr28 resistance gene previously reported in other SHW lines. These results demonstrate the value of the NIAB_WW_SHW_NAM population for genetic mapping and provide the first evidence of Yr28 working in current UK environments and genetic backgrounds. These examples, coupled with the evidence of commercial wheat breeders selecting promising genotypes, highlight the potential value of the NIAB_WW_SHW_NAM to variety improvement.

The influence of mitochondria-targeted antioxidants, plastoquinone derivatives on the resistance of grain crops to water deficiency

The article presents the results of a study of the influence of plastoquinone derivatives: 10-(6'-plastoquinonyl)decyltriphenylphosphonium (SkQ1) and 10-(6′-methylplastoquinonyl) decyltriphenylphosphonium (SkQ3) on the resistance of grain crops to soil moisture deficiency. The object of the study were seedlings of spring barley (Hordeum vulgare L.) cultivar “Sokol” and winter wheat (Triticum aestivum L.) cultivar “Kalym”. The growth rates of plants were studied for 14 days under normal conditions and with a lack of moisture, pre-treated with 2.5 nm solutions of SkQ1 and SkQ3. It has been shown that treating seeds with solutions of SkQ1 and SkQ3 increases the growth rate of the studied crops under conditions of lack of moisture compared to the control. Also, in the roots and leaves of 14-day-old barley seedlings, an analysis of the transcriptional activity of the genes SodA1, SodB, GR, GST1, GST6, Cat1, Cat2, Apx1, encoding oxidative stress proteins, was carried out. It was shown that a decrease in soil moisture by 1.8 and 2.0 times compared to the control reduces to varying degrees the weight of roots and leaves in 14-day-old barley seedlings and increases the transcriptional activity of all studied genes in both leaves and roots. Treatment of seeds with solutions of SkQ1 and SkQ3 under conditions of moisture deficiency increases the dry weight of barley roots and leaves and reduces the transcriptional activity of the studied genes in the roots. Keywords: PLASTOQUINONE DERIVATIVES, SkQ1, SkQ3, MITOCHONDRIA-TARGETED ANTIOXIDANTS, ROS, SOIL MOISTURE DEFICIENCY, STABILITY, TRANSCRIPTIONAL GENE ACTIVITY

Copy number variation at Vrn-A1 and haplotype diversity at Fr-A2 are major determinants of winter survival of winter wheat (Triticum aestivum L.) in Eastern Canada

Winter survival is an essential trait for winter wheat ( Triticum aestivum L.) cultivars grown in high latitude regions such as Eastern Canada. Indoor studies have identified that copy number variation of genes influencing freezing is an essential component. Although Canadian winter wheat is predominantly grown in Eastern Canada, the extent to which allele variation in freezing tolerance genes affects winter survival in this region remains unknown, as there are presently no studies characterizing such variation in Canadian winter wheat germplasm. In this study, we characterized a panel 415 Canadian winter wheat cultivars for haplotype diversity of the Frost Resistance-2 ( Fr-A2) locus and copy number variation of Vernalization-A1 ( Vrn-A1) and C- repeat binding factors- A14 ( CBF-A14). Additionally, this study evaluates each gene’s effect on winter survival across two locations and 2 years. We found that a combination of Vrn-A1 copy number and Fr-A2 haplotype accounted for 67.38% of the genotypic variance. Most of the cultivars tested (77.3%) carry the allele combination of three copies of Vrn-A1 and the Fr-A2-T haplotype, which was associated with the best winter survival. Interestingly, copy number of Vrn-A1 did not significantly affect heading time, therefore, selecting for higher copy number of Vrn-A1 would not affect maturity.

Diversity of chemical composition and nutritional value in grain from selected winter wheat cultivars grown in south-western Poland

Given the low protein coverage by legumes in Poland, alternatives (with high protein content and high nutritional value) are being sought (with high protein content and high nutritional value of protein) that could replace these plants. Cereal cultivation dominates in Poland; hence, the search for high-value plants will also consider this group of plants. The aim of the study was to compare the nutritional value of proteins from two wheat cultivars. A field experiment conducted in Zawidowice in south-western Poland in 2019 investigated the nutritional values of two winter wheat cultivars: Aurelius and Activus. These two cultivars were compared in terms of their chemical composition, the biological value of their proteins for animal nutrition, and the content of macro- and microelements. Significant differences in chemical composition were found between the tested wheat cultivars. In terms of the chemical composition, i.e. the content of protein, fiber and ash, the Activus cultivar was characterized by significantly better parameters. This cultivar also had significantly higher gross energy. In turn, a significantly higher content of essential amino acids, i.e. lysine, cysteine, tryptophan, histidine, leucine, ioleucine, and valine, was found in the Aurelius cultivar; therefore, the indicators determining the biological value of the protein are more favorable in the Aurelius cultivars. Meanwhile, in terms of selected macro- and microelements the Auerlius cultivar was more valuable. Varietal progress is necessary to obtain cultivars with the essential nutrients needed by animals to satisfy their dietary requirements.

COMPARATIVE RESPONSE OF TWO WHEAT VARIETIES TO BASAL AND SPLIT POTASSIUM NUTRITION UNDER FIELD CONDITIONS

Potassium (K) is an essential plant nutrient. Several research studies are available on the basal application of K concerned with yield and quality of wheat (Triticum aestivum L.). Conversely, very limited studies are available on the split application of K. During 2018-2019, a field experiment was performed at the Southern Wheat Research Station, Agriculture Research Institute, Tandojam, Pakistan to determine the importance of the right time for K fertilization in wheat. The experiment included 18 plots, each having an area of 12m2 (4m × 3m) involving two cultivars of winter wheat, viz. Benazir and Sindhu, sown in two-factor Randomized Complete Block Design, arranged in a split pattern (main plots = varieties, sub plots = treatments). Three K fertilization levels were tested, i.e. T1 = No K fertilization, T2 = 50 kg K2O ha-1 applied at the time of sowing, T3 = two splits of K, i.e. 25 kg K2O ha-1 applied at sowing and 25 kg K2O ha-1 applied at grain filling stage (top dressing). According to results, the yield components showed a positive enhancement upon split application of K as compared to basal application in terms of significantly higher (p

Registration of ‘KS Big Bow’ hard white winter wheat

Abstract‘KS Big Bow’ (Reg. no. CV‐1206, PI 701521), a hard white winter wheat (Triticum aestivum L.) cultivar, was developed by the wheat breeding program at the Agricultural Research Center–Hays, Kansas State University, and released by the Kansas Agricultural Experiment Station in 2022. KS Big Bow was selected from a single cross of KS050223M‐2/KS11HW15 using a modified bulk breeding method. The main objective of this cross is to release a competitive hard white winter wheat cultivar with adaptation to the dryland production in western Kansas. KS Big Bow is an F5‐derived line and was tested in yield trials from 2017 to 2022 in Kansas before its release. It has performed well in dryland yield trials in western Kansas. KS Big Bow has a medium to medium‐early maturity and medium plant height. Its test weight and straw strength are good. KS Big Bow has a good disease‐resistant package including resistance to Wheat streak mosaic virus, moderate resistances to stripe rust (caused by Puccinia striiformis Westend. f. sp. tritici Erikss.) and stem rust (caused by P. graminis Pers f. sp. tritici Eriks. & E. Henn.), and intermediate resistance to Barley yellow dwarf virus. Its milling and baking qualities are about average.

Height inheritance in durum wheat (Triticum durum Desf.) hybrids with D<sub> 2</sub> and D<sub> 3</sub> hybrid dwarfing genes

Background. Durum wheat (BBAuAu, 2n=28) carries the D2 and D3 hybrid dwarfing genes. A study of the nature of D genes and a research of their influence on the adaptive and selectively valuable traits of hybrid plants with hybrid dwarfing genes is of theoretical and practical interest. It was previously established that the dominant alleles of the D2 and D3 genes significantly reduce the height of durum wheat hybrid plants and positively affect the kernel size and vitreousness. The purpose of the present work was to study the inheritance of height in hybrids obtained by crossing a semi-dwarf durum winter wheat cultivar with lines carrying hybrid dwarfing genes. Material and methods. The material of the study was four lines of durum wheat: L-961, L-962, L-963 and L-964 carrying hybrid dwarfing genes D2 and D3, a cultivar of semi-dwarf winter durum wheat ‘Krupinka’ (k-64725) with the rht1 gene, and hybrids of these lines with this cultivar. ‘Krupinka’ was used as the female parent in hybridization by controlled pollination. The degree of dominance was determined according to Beil and Atkins. Statistics were performed using the Pearson’s -x2 test. Results and conclusions. The analysis of plant lines of durum wheat with the D2 and D3 hybrid dwarfing genes showed that the average height of the ‘Krupinka’ × L-962 and ‘Krupinka’ × L-963 hybrids was 30 cm lower compared to the tall parent, the degree of dominance was 0.9 and 1.9 respectively. In hybrids with lines L-961 and L-964, there was no dominance of short stature. The height variability in F2 hybrids was continuous and prevented combining them into any phenotypic classes. The F3 families of ‘Krupinka’ × L-962 and ‘Krupinka’ × L 963 hybrids segregated by height into three phenotypic classes. The actual ratio of phenotypic classes did not contradict the theoretical one of 10:3:3. The obtained numerical ratios of F3 families are generally similar to those found in the literature. A distinctive feature is the absence of recessive alleles in D genes. It is assumed that the latter are regulators of phytohormone gene depression and do not have recessive alleles. It will be more correct to designate the observed phenotypic classes as D2D2 i and D3D3 i, where D2 i и D3 i denote homologues of chromosomes with a different number of multigenes. Conclusion. The study of height inheritance in the obtained hybrids indicated the presence of dominant D2 and D3 genes in the L-962 and L-963 lines and of the semi-dominant D3 gene in the L-961 line. A distinctive feature of height inheritance in durum wheat lines with the D2 and D3 hybrid dwarfing genes is the absence of recessive alleles in the D genes, i.e. no dominance of short stature

Elucidating the attributes of winter wheat grain quality under reduced nitrogen input through near‐infrared spectroscopy

AbstractBackground and ObjectivesResearch in crop science is usually conducted in studies with a small number of plants and crops. The aim of this project was to investigate whether near‐infrared spectroscopy (NIRS) can contribute to the analysis of such small data sets. For this purpose, NIR spectra of a small sample set of whole‐grain wheat flours of two winter wheat cultivars harvested from greenhouse and field experiments with different fertilization management were analyzed.FindingsPrincipal component analysis (PCA) facilitated the discrimination of samples based on fertilization, baking volume, and growing conditions for each wheat cultivar. In addition, PCA allowed the differentiation of wheat cultivars in a data set containing both cultivars. Spectra–structure relationships were also established. Accurate calibrations with R2 of .98, .98, and .54 were obtained for fertilization, crude protein concentration, and baking volume, respectively, even for a small data set of 10 samples of wheat cultivar Discus.ConclusionThe NIR spectra of whole‐grain wheat flour samples provided high‐resolution information on various parameters such as fertilization, baking volume, wheat cultivar, and growing site. This study demonstrates that NIRS is a valuable and efficient tool for the analysis of small data sets in crop science. This illustrates the effectiveness of the elegant NIRS method.Significance and NoveltyIn this study, small data sets of whole‐grain wheat flour from crop science experiments were analyzed by NIRS. Characteristic changes of the NIR spectra based on applied fertilizer amount, crude protein concentration, baking volume, growing site, and wheat cultivar were revealed. The detection of cause‐and‐effect relationships between spectra and chemical properties of samples contributes to a better understanding of NIR spectra of wheat flours in an interpretative way.

Advantageous spike-to-stem competition for assimilates contributes to the reduction in grain number loss in wheat spikes under water deficit stress

This study was conducted to investigate the mechanisms of assimilate distribution and sugar metabolism in spike-stem that inhibit the formation of fertile florets and grains per spike in winter wheat under pre-reproductive drought stress. Two winter wheat cultivars, CH58 (relatively strongly drought tolerant) and LH6 (relatively weakly drought tolerant), were subjected to successive soil drought treatments from jointing to heading during the 2020–2022 growing seasons. The results showed that pre-reproductive drought stress intensified the degradation and abortion of wheat florets. Compared to CH58, the decrease in the number of fertile florets and grains per spike of LH6 under drought stress increased by an average of 5.3%−8.0% and 8.3%−9.0%, respectively. Drought significantly inhibited the distribution of 13C-photosynthates in wheat spikes (15.7%−24.7%) and stems (8.5%−11.7%) during the booting stage. The number of differentially expressed genes enriched in starch and sucrose metabolic pathways was much higher in the spike and stem of LH6 than in those of CH58. Drought significantly reduced sucrose and hexose in young spikes but increased hexose and fructan concentrations in stems. Compared to LH6, the higher invertase activity and accompanying high expression of sugar transporter protein (STP) in CH58 spikes under drought stress contributed to the utilization of sucrose in young spikes. Additionally, under severe drought, the higher fructan concentration and expression of sugar transport proteins (SWEET and SUT) in the stem of CH58 improved the ability of the stem to transport assimilates to young spikes and thus alleviated the loss of grain number per spike. Exogenous spermidine optimized hexose and sucrose allocation in young wheat spikes and stems after drought stress, thereby increasing the number of fertile florets under drought stress. Overall, the ability of the dominant spike to utilize sugar and the ability to compete for assimilates between the spike and stem contribute to the resistance to drought stress-induced grain reduction in the spike. Exogenous chemicals can regulate the number of fertile florets through this pathway, thereby promoting the formation of wheat grain number.

The Effect of Water Availability on the Carbon Content of Grain and Above- and Belowground Residues in Common and Einkorn Wheat.

The carbon (C) fixed by crops, which is exported with harvest and retained as postharvest residues in a field, is important for calculating the C balance. The aim of this study was to determine the effect of water availability on the C content in whole wheat plants. In a three-year field trial, the weights of grain, straw, chaff, stubble, and roots of two cultivars of winter wheat (Triticum aestivum L.) and one cultivar of einkorn wheat (Triticum monococcum L.) and their carbon contents were determined in water stress, irrigation, and rain-fed control treatments. The water availability, year, and cultivar had a significant influence on the C content in aboveground plant parts, but the effect of water on grain C was weak. The C content decreased with irrigation and increased with drought, but the differences were small (at most, 3.39% in chaff). On average, the C contents of grain, straw, chaff, and roots reached 45.0, 45.7, 42.6, and 34.9%, respectively. The amount of C exported with grain and left on the field in the form of postharvest residues depended on the weight of the total biomass and the ratio of grain to straw and residue. Whole plant C yield reached 8.99, 7.46, and 9.65 t ha-1 in rain-fed control, stressed, and irrigated treatments, respectively, and 8.91, 9.45, and 7.47 t ha-1 in Artix, Butterfly, and Rumona, respectively. Irrigation significantly increased the C content in grain and straw (but not in chaff, stubble, and roots) in comparison with water shortage conditions. On average, a grain yield of 1 t ha-1 corresponded to an average export of 0.447-0.454 t C ha-1 in the grain of all cultivars and inputs of 0.721, 0.832, and 2.207 t C ha-1 of residue to the soil in the form of straw and postharvest residue in the two cultivars of common wheat and one of einkorn. The results of the study provided reliable data for the calculation of the C balance of wheat under conditions of different water availability.

Heat stress during male meiosis impairs cytoskeletal organization, spindle assembly and tapetum degeneration in wheat.

The significance of heat stress in agriculture is ever-increasing with the progress of global climate changes. Due to a negative effect on the yield of staple crops, including wheat, the impairment of plant reproductive development triggered by high ambient temperature became a restraint in food production. Although the heat sensitivity of male meiosis and the following gamete development in wheat has long been recognized, a detailed structural characterization combined with a comprehensive gene expression analysis has not been done about this phenomenon. We demonstrate here that heat stress severely alters the cytoskeletal configuration, triggers the failure of meiotic division in wheat. Moreover, it changes the expression of genes related to gamete development in male meiocytes and the tapetum layer in a genotype-dependent manner. 'Ellvis', a heat-tolerant winter wheat cultivar, showed high spikelet fertility rate and only scarce structural aberrations upon exposure to high temperature. In addition, heat shock genes and genes involved in scavenging reactive oxygen species were significantly upregulated in 'Ellvis', and the expression of meiosis-specific and major developmental genes showed high stability in this cultivar. In the heat-sensitive 'Mv 17-09', however, genes participating in cytoskeletal fiber nucleation, the spindle assembly checkpoint genes, and tapetum-specific developmental regulators were downregulated. These alterations may be related to the decreased cytoskeleton content, frequent micronuclei formation, and the erroneous persistence of the tapetum layer observed in the sensitive genotype. Our results suggest that understanding the heat-sensitive regulation of these gene functions would be an essential contribution to the development of new, heat-tolerant cultivars.

Field phenotyping of ten wheat cultivars under elevated CO2 shows seasonal differences in chlorophyll fluorescence, plant height and vegetation indices.

In the context of climate change and global sustainable development goals, future wheat cultivation has to master various challenges at a time, including the rising atmospheric carbon dioxide concentration ([CO2]). To investigate growth and photosynthesis dynamics under the effects of ambient (~434 ppm) and elevated [CO2] (~622 ppm), a Free-Air CO2 Enrichment (FACE) facility was combined with an automated phenotyping platform and an array of sensors. Ten modern winter wheat cultivars (Triticum aestivum L.) were monitored over a vegetation period using a Light-induced Fluorescence Transient (LIFT) sensor, ground-based RGB cameras and a UAV equipped with an RGB and multispectral camera. The LIFT sensor enabled a fast quantification of the photosynthetic performance by measuring the operating efficiency of Photosystem II (Fq'/Fm') and the kinetics of electron transport, i.e. the reoxidation rates Fr1' and Fr2'. Our results suggest that elevated [CO2] significantly increased Fq'/Fm' and plant height during the vegetative growth phase. As the plants transitioned to the senescence phase, a pronounced decline in Fq'/Fm' was observed under elevated [CO2]. This was also reflected in the reoxidation rates Fr1' and Fr2'. A large majority of the cultivars showed a decrease in the harvest index, suggesting a different resource allocation and indicating a potential plateau in yield progression under e[CO2]. Our results indicate that the rise in atmospheric [CO2] has significant effects on the cultivation of winter wheat with strong manifestation during early and late growth.