Search Results (197)

Grain number is a primary agronomic trait for targeted yield improvement, with the prospect of enhanced grain production leading to greater food security. Given the complex polygenic nature of the grain number trait, large sample sizes are essential for effective QTL identification. The implementation of trained computer vision models for grain detection offers a timely and cost-effective solution for rapid QTL isolation. In this study, we trained a grain detection model using Ultralytics’ You Only Look Once (YOLOv11) framework. Training was completed on 1000 images of barley spikes, derived from a doubled haploid (DH) population descended from Hindmarsh and RGT Planet. The trained model, termed BarleyGC, achieved satisfactory accuracy metrics (mAP50–95 = 71.9%, recall = 96.7%, precision = 97.1%). Phenotypic characterisation of the DH population was completed with BarleyGC on a distinct collection of 973 images. The Pearson correlation coefficient (r) between model and manual-derived counts for the trait of grain number per spike was 0.895 (p < 0.0001), and 92.4% of all measurements fell within three grains of the manual measurement. Downstream QTL analysis on the phenotype data (n = 153 DH lines), revealed a QTL peak at position 224.959 cM on the genetic map (LOD = 3.14), named qGN-2H. The QTL region contained 21 candidate genes—including HORVU2Hr1G092290 (HORVU.MOREX.r3.2HG0184740), encoding the six-rowed spike 1 (Vrs1) gene—a well-characterised major regulator of row-type divergence and lateral spikelet development. Our study demonstrates the power of the YOLOv11 framework for grain quantification, with BarleyGC capable of grain detection directly from images of intact spikes in two-rowed barley varieties—thus achieving accelerated sample processing for the grain number trait. Full article

Salinity is a major abiotic stress that limits wheat productivity in arid and semi-arid regions. The present study evaluated 20 wheat (Triticum aestivum L.) genotypes, including local and improved varieties, under saline soil conditions (ECe ≈ 6.3 and 12.5 dS m⁻¹) to assess their performance and tolerance mechanisms. The experiment was conducted using a randomized complete block design with three replicates. Data were recorded for grain yield, number of spikes per square meter, number of kernels per spike, 1000-grain weight, sodium (Na⁺), potassium (K⁺), and K⁺/Na⁺ ratio. Analysis of variance revealed significant differences among the genotypes for all traits. Grain yield ranged from 0.51 t ha⁻¹ to 1.14 t ha⁻¹, with Bhan 2000, Local, P7, and Sakha 93 showing superior performance, whereas IC15, P6, and IC96 were most affected. A strong positive correlation was observed between grain yield and both kernels per spike (r = 0.75) and K/Na ratio (r = 0.55), whereas Na content was negatively correlated with yield (r = −0.35). Genotypes with higher K⁺/Na⁺ ratios exhibited better ionic balance and salt tolerance. Based on the combined evaluation of productivity and ionic homeostasis, Bhan 2000, Local, P7, and Sakha 93 were clearly identified as the most salt-tolerant genotypes. These genotypes maintained higher grain yields together with optimal K⁺/Na⁺ ratios, reflecting efficient ionic regulation mechanisms. The integrated approach adopted in this study strengthens selection accuracy and highlights these genotypes as promising candidates for cultivation in saline environments and as donor parents in wheat breeding programs targeting salinity tolerance. Full article

Grain number and size are important agronomic traits determining grain yield, and yield improvement depends on exploring functional variations of key regulatory genes. Mitogen-activated protein kinase 6 (MAPK6) plays a key role in crop development; however, its function and variation in wheat remain largely unclear. In this study, we aimed to characterize the function and haplotype variations of TaMAPK6-7A in wheat and develop functional molecular markers for marker assisted breeding. We identified three TaMAPK6 homoeologs on 7A, 7B, and 7D in wheat through bioinformatics analysis and revealed their evolutionary trajectory by phylogenetic analysis, with clear monocot-dicot lineage divergence and TaMAPK6 homoeolog clustering matching with hexaploid wheat’s allopolyploid origin. Spatiotemporal expression analysis showed that the TaMAPK6 homoeologs constitutively expressed in wheat tissues and were highly abundant in endosperm, spike, grain, and anther, with TaMAPK6-7A showing slightly higher transcript levels. In an ethyl methanesulfonate (EMS)-induced Jing411 mutant library, we identified a loss-of-function mutant of TaMAPK6-7A (J7633452), which exhibited severely reduced grain number per spike, impaired anther fertility, and increased grain size. Natural variation analysis of a large set of wheat accessions identified two major haplotypes of TaMAPK6-7A, with Type I was identical to the reference genome cultivar ‘Chinese Spring’, and Type II was consistent with the elite wheat cultivar ‘AK58’. We developed a PCR marker to accurately distinguish the two haplotypes and genotyped 192 wheat cultivars and elite breeding lines. Phenotypic evaluation indicated that Type II was an elite haplotype significantly associated with higher grain number per spike. This study characterizes TaMAPK6-7A as a key regulator of grain number per spike, providing a gene and molecular marker for marker-assisted breeding to improve grain yield. Full article

Highland hulless barley is a core grain crop on the Qinghai–Tibet Plateau. Limited research on hybrid vigour and combining ability has constrained hybrid breeding progress. This study employed eight Himalayan barley varieties as parents and utilized the NCII design to generate 16 hybrid combinations. Hybrid vigour, combining ability, and genetic parameters were analyzed for 11 core ear and grain agronomic traits. Results indicated significant hybrid vigour across all traits: combination 1789 × 84 showed the highest total ear weight (midparent advantage: 116.74%, super-parent advantage 104.60%) and grain weight per ear (mid-parent advantage 126.78%, super-parent advantage 120.13%) in combination 1789 × 84, while thousand-grain weight showed the strongest hybrid vigour in combination 74 × 84 (mid-parent advantage 41.64%). Complementarity ability analysis revealed that parent 69 exhibited extremely significant positive general combining ability (GCA) effects across multiple core traits, making it the optimal parent for comprehensive traits; combination 1791 × 69 demonstrated the highest specific combining ability (SCA) effects. Genetic parameters indicated that traits such as the number of filled grains and total ear weight were primarily influenced by additive effects, as indicated by the higher GCA variance components compared with SCA variance components for these traits. Furthermore, thousand-grain weight was identified as a key integrative trait linking spike and grain characteristics, and its improvement can simultaneously enhance multiple yield-related traits. The superior parents (69, 1789, 1791) and strong-advantage combinations identified in this study provide a scientific basis for parent selection, combination screening, and breeding strategy formulation in high-yielding hybrid breeding of barley. Full article

Grain number per spike (GNS) is a key component of wheat yield, yet its genetic architecture remains incompletely understood. This study phenotyped 610 wheat accessions for GNS in four environments and genotyped them using 429,721 single nucleotide polymorphisms (SNPs). The phenotypes were associated with the SNPs using a three-variance multi-locus random-SNP-effect mixed linear model (3VmrMLM) to identify quantitative trait nucleotides (QTNs), as well as QTN-by-environment (QEI) and QTN-by-QTN (QQI) interactions. These genetic components and residual error explained approximately 18%, 31%, 28%, and 23% of the phenotypic variance, respectively. Two and one previously reported genes were found around QTNs and QEIs, respectively. Bioinformatics and haplotype analyses subsequently yielded 25 candidate genes, 22 gene-by-environment interactions (GEIs), and 24 gene-by-gene interactions (GGIs) around the QTNs, QEIs, and QQIs, respectively. Notably, TraesCS1D01G280000, the wheat homolog of OsRopGEF10, was located near a major QTN explaining over 10% of the total phenotypic variation. A gene interaction network constructed from all identified genes highlighted the central role of GGIs in GNS regulation. Environmental variation may reshape the regulatory network through GEIs. Furthermore, superior haplotypes of 12 candidate genes were identified, providing valuable targets for improving wheat yield. Overall, this study dissects the genetic architecture of GNS and offers practical resources for wheat molecular breeding. Full article

Optimizing plant density is critical for improving wheat yield and resource-use efficiency, but whether a single density recommendation applies to varieties differing in individual spike productivity under drip fertigation remains unclear. A two-year field experiment (2023–2024 and 2024–2025) was conducted with two winter wheat varieties contrasting in spike type: a multi-spike type (Jimai23, MS) and a large-spike type (Jimai24, LS). Four target densities (200, 300, 400, and 500 plants m⁻²) were evaluated under drip fertigation to quantify yield formation, dry matter production, radiation interception and use, N uptake and nutritional status, and water use. Grain yield responses to density differed markedly between varieties. MS showed an increase–plateau–decline pattern, with the highest yields at 300–400 plants m⁻² (10.13–10.97 t ha⁻¹), whereas LS increased to 400 plants m⁻² and remained relatively stable at 500 plants m⁻² (9.97–10.55 t ha⁻¹). Increasing density increased spike number, LAI, intercepted solar radiation (ISR), and soil water consumption but decreased grains per spike, grain weight, and yield per spike in both varieties. Yield variation was more strongly associated with post-anthesis dry matter production than with grain number. Although MS intercepted more radiation, its radiation use efficiency (RUE), post-anthesis N uptake, N nutrition index (NNI), harvest index, agronomic N-use efficiency, fertilizer N recovery efficiency, and water use efficiency (WUE) declined sharply at high density. In contrast, LS maintained relatively stable RUE, higher NNI, stronger N uptake, and higher WUE at medium-to-high densities. These results demonstrate that optimal density under drip fertigation is variety-dependent and should be determined using a trait-based framework integrating nitrogen–radiation–water use efficiency. Full article

Under rainfed conditions of Northern Kazakhstan, the effects of microbiologically processed cattle manure (CCM) on soil agrochemical and microbiological properties, yield structure, and spring wheat productivity were evaluated over two contrasting growing seasons (2024–2025). Field experiments on chernozem soils tested manure rates of 5–30 t ha⁻¹. Favorable hydrothermal conditions in 2024 enhanced fertilizer efficiency compared with the drier 2025 season. CCM application increased soil nitrate nitrogen from low (<8 mg kg⁻¹) to medium levels (8–12 mg kg⁻¹), while available phosphorus and potassium increased by 15–35% relative to the control across key growth stages. The abundance of major functional microbial groups increased by 1.5–3.0-fold, particularly nitrogen-transforming and cellulose-degrading microorganisms. Grain yield improved significantly in both years, with the highest and most stable yields observed at 15–20 t ha⁻¹, resulting in yield gains of 18–32% compared with the control. Yield improvements were associated with increases in grain number per spike (up to 25–27 grains) and grain weight per spike (up to 1.42–1.62 g). Higher manure rates (20–30 t ha⁻¹) did not confer additional yield benefits. Overall, these findings indicate that moderate CCM application effectively enhances soil fertility, stimulates microbial activity, and improves wheat productivity under dryland conditions. Full article

Late-sown wheat, which misses the optimal photoperiod and temperature for growth, suffers irreversible losses in both grain number per spike and thousand-grain weight, resulting in severe yield reductions. To this end, a two-year field experiment was conducted to evaluate the effects of application timing (S1 at the booting stage and S2 at the flowering stage) and concentration (T0 = 0 μmol L^–1, T1 = 376 μmol L^–1, T2 = 501 μmol L^–1, T3 = 626 μmol L^–1) on the photosynthetic physiology, grain number per spike, thousand-grain weight, and quality of late-sown wheat, aiming to elucidate the mechanism by which TiO₂ enhances the yield quality–efficiency relationship in wheat. The results showed that the foliar application of TiO₂ significantly enhanced the accumulation of photosynthetic pigments (SPAD) and spectroscopic indices (CHI, PRI) in wheat flag leaves, markedly improved the net photosynthetic rate, and increased the activities of antioxidant enzymes (SOD, POD) while reducing the accumulation of membrane lipid peroxidation products (MDA), with the T2 treatment exhibiting the most pronounced effect. Foliar application of TiO₂ at the S1 stage significantly increased the number of florets and spikelets, improved grain setting rates, and consequently boosted the grain number per spike. Application of TiO₂ during the S2 stage significantly enhanced grain filling rates, thereby increasing thousand-grain weight and achieving yield improvement. T2 demonstrated optimal performance under both conditions, enhancing grain storage capacity and morphological traits. This approach not only increased late-sown wheat yields but also improved grain quality indicators such as protein content, wet gluten, and sedimentation value. Therefore, applying 501 μmol L^–1 (T2) TiO₂ during the booting stage (S1) appears to be effective for achieving high yields and superior quality in late-sown wheat. Full article

To identify adaptive cultivation strategies for strong-gluten winter wheat under conditions of increasing autumn temperatures and changing precipitation patterns in the Huang–Huai–Hai region, a field experiment was conducted with cultivars Jimai 44 and Zhongmai 578. Field experiments were conducted during the 2023–2024 and 2024–2025 growing seasons, using three sowing dates (T2–T4, 20 October to 3 November) in the first year and four sowing dates (T1–T4, 13 October to 3 November) in the second year, each combined with three seeding rates (M1–M3) that were increased by 52.5 kg ha⁻¹ for every 7-day delay in sowing. This design evaluated how sowing date and seeding rate regulate photosynthesis, dry matter dynamics, and yield. The results showed that post-anthesis dry-matter accumulation, harvest index, grain number per unit area, and grain yield responded quadratically to delayed sowing and increased seeding rate. Delayed sowing increased flag-leaf SPAD but reduced dry matter at anthesis and maturity, pre-anthesis translocation, spike number, and thousand-kernel weight. Higher seeding rate decreased SPAD, net photosynthetic rate, grains per spike, and kernel weight. The T2M2 treatment optimized canopy structure, enhanced photosynthesis, maintained efficient dry matter production and partitioning, and balanced yield components, achieving the highest grain yield. Although severe delays in sowing reduced yield, increasing the seeding rate under late sowing compensated for the reduced spike number and mitigated yield losses. The T2M2 combination and the late-sowing with the incremental-seeding technique offer practical strategies for climate-resilient, high-yield wheat production in the region. Full article

Lodging is a major constraint limiting wheat (Triticum aestivum L.) yield and quality globally. Despite dwarfing genes reducing plant height and mitigating lodging risk and losses, lodging still severely limits wheat yield. Few studies have examined how wheat breeding has altered the sensitivity of yield to lodging, especially its penalties in grain number and grain weight at specific spike positions. Two separate experiments were conducted in the Huang-Huai-Hai region of China: a lodging-period experiment (two genotypes, five periods) during the 2011–2013 growing seasons, and a lodging-angle experiment (three genotypes, five angles) during the 2019–2021 growing seasons. The results showed that grain number per m² (GNO), average grain weight (AGW), and grain yield (GY) all increased linearly with genotype release year. Lodging significantly reduced GNO and AGW, and consequently GY in all genotypes, but these losses declined linearly with the year of genotype release, indicating that modern genotypes suffer less yield penalty under lodging. Furthermore, lodging at any stage reduced the weight of both superior and inferior grains within the spike, whereas only pre-anthesis lodging decreased grain number per spike. Inferior grains, owing to their higher environmental sensitivity, showed larger reductions in both grain number and grain weight per spike than superior grains. Across all genotypes, lodging decreased grain number and grain weight per spike in the order apical > basal > central, and the relative losses declined linearly with year of genotype release. Moreover, lodging-induced losses in ¹³C assimilation followed the order old > intermediate > modern across genotype eras; the reduction in ¹³C assimilation within the spike ranked apical > basal > central, and that in superior grains exhibited the same pattern. Concurrently, the allocation of ¹³C assimilates to inferior grains was markedly inhibited across all spike positions, with the reduction magnitude significantly exceeding that in superior grains. Lodging-induced differential changes in ¹³C assimilation among grain positions within each spike layer are associated with the uneven reductions in grain number and average grain weight across the spike. These findings may provide a basis for lodging-resistant wheat production and cultivar breeding. Artificial lodging induction can serve as a reliable strategy to efficiently evaluate yield stability and lodging tolerance. However, its applicability to other wheat regions needs further verification via multi-location and multi-cultivar trials. Full article

Soil salinity is a major constraint to wheat production worldwide. Efficient screening of salt-tolerant cultivars is essential for breeding programs, yet a rapid and reliable evaluation system based on full-life-cycle salt stress treatment is lacking. To address this, we conducted a hydroponic experiment encompassing the entire growth cycle of 37 wheat cultivars under control and salt stress (85.5 mM NaCl). Using principal component and stepwise regression analyses on 15 agronomic and yield-related traits, we identified five key indicators—total dry weight, root dry weight, plant height, thousand-grain weight, and number of grains per spike—that effectively represent overall salt tolerance. Based on a comprehensive evaluation value (D-value), the cultivars were classified into five distinct categories: highly salt-tolerant, salt-tolerant, moderately salt-tolerant, weakly salt-tolerant, and salt-sensitive. Notably, the highly salt-tolerant cultivar ‘Yangfumai 8′ and the salt-sensitive cultivar ‘Yangmai 22’ were selected as representative extremes. A subsequent pot experiment confirmed significant physiological differences between them in antioxidant enzyme activities (SOD, POD, CAT) and proline accumulation under salt stress. This study establishes a practical and efficient screening framework, providing breeders with a simplified index set for high-throughput evaluation and offering ideal contrasting materials for in-depth physiological research on salt tolerance mechanisms in wheat. Full article

Irrigation practices and nitrogen (N) addition play pivotal roles in wheat production, and their rational coordination can significantly enhance N, phosphorus (P), and potassium (K) use efficiency and yield of wheat. However, the comprehensive effects of irrigation practices and N addition rates on N, P, and K accumulation and utilization and yield of wheat in dryland remain unclear. A field experiment with two irrigation practices (W0, zero-irrigation and W1, one-off irrigation), and four N addition rates (0, 120, 180, and 240 kg N ha⁻¹, represented by N0, N120, N180, and N240, respectively) was conducted in 2021–2022 and 2023–2024. Compared to W0N0, W1N180 significantly increased wheat grain yield, spike number, and grains per spike by 46.4%, 35.9%, and 18.9%, respectively. Wheat yield and N, P, and K accumulation reached the maximum value at N180 or N240. One-off irrigation significantly improved the uptake efficiency and fertilizer partial factor productivity for N, P, and K, whereas increased N addition enhanced these parameters specifically for P and K. However, N180 treatment increased N uptake efficiency, N fertilizer partial factor productivity, P internal efficiency, and K internal efficiency by 22.2%, 31.1%, 9.4%, and 5.9%, respectively, compared to N240 under one-off irrigation. In addition, W1N180 significantly increased above-ground N, P, and K accumulation by 45.8%, 52.8%, and 51.8%, as well as pre-anthesis N and P translocation by 48.5% and 47.0%, respectively, compared to W0N120. Consequently, the W1N180 strategy not only improved wheat yield but also optimized N, P, and K accumulation, pre-anthesis N and P translocation, and nutrient use efficiency. Therefore, one-off irrigation combined with N180 can be recommended for enhancing wheat yield and nutrient use efficiency in dryland. Full article

This study aimed to develop a methodology to evaluate, through RGB image processing, the wheat cultivar TRIO Calibre under three irrigation levels (100, 50, and 25%), with or without the application of Bacillus aryabhattai, in Brazilian Cerrado soil. The experimental scheme was a $3\times 2$ factorial design with five replicates. Images were collected, numbered, and organized into files, which were transformed to grayscale. During processing, the grayscale level co-occurrence matrix (GLCM) technique was applied and implemented in four main directions (0°, 45°, 90°, and 135°), and 13 statistical descriptors were extracted. At physiological maturity, the plants were harvested, and the following yield components were evaluated: plant height (PH), number of spikes per plant (NS), number of grains per spikes (NGS), average grain weight (AGW), and total prodution of grains (TPG). Irrigation influenced all the variables, with higher TPG and NS at 100% and 50% water and higher AGW at 25% water. The results indicated that the “contrast” descriptor in the 90° and 135° GLCM directions was the most efficient in differentiating treatments, which presented better performance in the 90° direction and was significantly correlated with the NS ($r=-0.48$, $p<0.05$) and TPG ($r=-0.46$, $p<0.05$). The analyses demonstrated that the methodology has the potential to be adapted for the analysis of under controlled conditions, contributing to more sustainable agricultural practices. Full article

Increasing planting density is an effective measure to mitigate the negative impacts of late-sowing on yield formation in winter wheat. However, the physiological mechanisms underlying source-sink coordination and high-yield performance through density regulation in hybrid wheat with high yield potential remain unclear. A two-year field experiment was conducted using the hybrid variety Jingmai 17 and conventional variety Jimai 22 as experimental materials, with three planting densities: 150 plants·m⁻² (M1), 300 plants·m⁻² (M2), and 450 plants·m⁻² (M3). The effects of planting density on the source-sink relationship and yield were systematically investigated. The results showed that both Jingmai 17 (2.4–9.7%) and Jimai 22 (1.4–10.6%) exhibited the most significant yield increases under the M2 treatment. This density maintained photosynthetic capacity during the mid-to-late grain-filling stage, delayed leaf senescence, promoted assimilate translocation to the grains, and simultaneously improved grain number per spike and thousand-grain weight by optimizing source-sink coordination efficiency. Compared with Jimai 22, the hybrid wheat Jingmai 17 demonstrated a significant yield advantage (8.2–10.1%), which was attributed to its stronger and more persistent source function, larger and more stable sink capacity, and higher source-sink coordination efficiency. In conclusion, under late-sowing conditions, the hybrid variety Jingmai 17 at a density of 300 plants·m⁻² achieved the most effective optimization of the source-sink relationship, fully exploited its yield potential, and achieved a balance between high and stable yield. This study provides a theoretical and practical cultivation reference for the selection of hybrid wheat varieties in this region. Full article

A sustainable approach to agricultural production and increasing interest in alternative wheat species have intensified research on simplified soil management systems under changing climatic conditions. A three-year field experiment (2018–2020) was conducted to evaluate the effects of tillage methods (plowing, shallow tillage, and strip-till) and hydrothermal conditions on yield formation and yield components in three wheat species: Triticum sphaerococcum, Triticum persicum, and Triticum aestivum ssp. vulgare. The results showed that weather conditions during the growing season strongly modulated species responses to tillage systems. Multivariate analyses confirmed that grain yield was mainly determined by fertile generative tiller density and grain number per spike, whereas thousand-grain weight played a secondary or compensatory role. In T. sphaerococcum, clear tillage effects occurred only in the most favorable year, when shallow tillage enhanced yield. T. persicum consistently responded positively to strip-till across all years, increasing grain yield by 35.5% compared with plowing. In T. aestivum, the direction of tillage effects depended on weather conditions, with shallow tillage being most beneficial under favorable moisture and plowing under drier conditions. Overall, simplified tillage systems can enhance the productivity of ancient wheat species without reducing the performance of common wheat, provided that soil management is aligned with prevailing hydrothermal conditions. Full article