The present investigation was designed to identify molecular marker loci linked to essential agronomic traits and oil content under contrasting salinity regimes, and to evaluate the stability of these associations within a globally representative safflower (Carthamus tinctorius L.) germplasm collection. Over two successive years, 100 accessions were evaluated, generating 341 polymorphic amplified fragment length polymorphism (AFLP) markers using 10 EcoRI/MseI primer combinations. These markers were subsequently employed in association mapping analyses encompassing 17 agronomic traits and their derived indices. Population structure assessment revealed three genetically distinct subgroups within the panel. Mixed linear model (MLM) analysis facilitated the identification of 140 significant MTAs under non-saline conditions and 128 MTAs under salinity stress. Several loci exhibited associations with multiple traits, suggesting either pleiotropic regulatory functions or tight genetic linkage. Markers M61/E37-1, M61/E37-16, M62/E41-15, M60/E38-9, M51/E41-31, M61/E40-20, and M47/E37-9 were consistently associated with salinity tolerance across environments. After confirmation, these MTAs represent valuable resources for marker-assisted selection and for the targeted introgression of favorable alleles into safflower breeding programs adapted to both optimal and saline conditions. Furthermore, the results provide a critical framework for fine-scale genetic mapping and the eventual isolation of causal genes and quantitative trait loci (QTLs) that confer salinity tolerance.

Defining the metabolic strategies employed by tall fescue to withstand and recover from drought events will be crucial for maintaining the performance and stability of turf and forage aspects in the future; however, research on this vital topic is scarce. This study assessed 142 tall fescue genotypes for forage production, physiological, and biochemical responses under two irrigation regimes from 2019 to 2021. In 2022, a two-month drought was imposed to evaluate post-drought recovery. Drought stress decreased photosynthetic pigments (5.26-27.89%) and yield (18.40-34.16%) in tall fescue genotypes. Simultaneously, antioxidant enzyme activities (catalase, ascorbate peroxidase, peroxidase) increased by 40%, 28%, and 31%, respectively, and osmo-protectants increased by 48.88-67.74%. Genetic variation among genotypes indicates potential for drought tolerance selection. The research demonstrates that drought tolerance and recovery in tall fescue are genetically variable and heritable, enabling selection for improved breeding. Under drought, catalase, ascorbate peroxidase, peroxidase, chlorophyll content, and proline can enhance forage yield. However, under control conditions, plant height and crown diameter predict yield in control conditions. Post-drought recovery relates to carbohydrate accumulation and antioxidant enzyme activity; genotypes 6 and 9 showed 20% higher recovery rates. Twenty-one top genotypes (12, 105, 3, 40, 1, 104, 4, 22, 86, 2, 11, 96, 5, 94, 88, 9, 89, 64, 106, 100, and 18) are highlighted for their productivity and drought resilience. Biochemical and physiological markers facilitate early drought tolerance screening, while this study's novelty lies in its integrated physiological, biochemical, and genetic approach.

Soil salinity limits barley productivity, worsened by domestication bottlenecks that reduced stress-adaptive diversity. We employed a multi-origin introgression strategy using 21 wild Hordeum spontaneum accessions from diverse Fertile Crescent ecotypes to restore ancestral resilience. These foreground segments were embedded in a single cultivated background, yielding a nested backcross population (NBP) and 63 advanced recombinant lines. Parents and lines were evaluated under saline and non-saline field conditions for Na+/K+ ratio, tissue hydration, osmotic adjustment, antioxidant metabolism, and productivity. Introgression generated superior phenotypes that outperformed both parents. High-performing genotypes exhibited a coordinated tolerance strategy involving moderate Na+ uptake with effective tissue tolerance (likely via enhanced vacuolar sequestration), balanced osmotic adjustment to maintain hydration with minimal metabolic cost, and efficient antioxidant responses that avoided defense-yield penalties seen in wild parents. These integrated mechanisms arose from recombining adaptive alleles from multiple wild origins, with Iranian germplasm contributing strongly. A composite selection index based on these physiological traits effectively distinguished tolerant genotypes and correlated with yield stability. Our findings demonstrate that salt tolerance in barley results from balanced coordination of physiological processes rather than maximal defensive activation. Multi-origin wild introgression offers a powerful approach to restore ancestral resilience while preserving agronomic performance.

Heat stress (HS) significantly impedes wheat production, making the development of heat-tolerant cultivars increasingly essential in the context of climate change. This study evaluated 153 elite spring wheat (Triticum aestivum L.) genotypes from the Wheat Association Mapping Initiative (WAMI) panel and three controls in field trials conducted during the 2020-2021 and 2021-2022 growing seasons at the Isfahan University of Technology research farm, Iran. Two sowing dates (SD; fall and spring) under full irrigation were employed to replicate HS conditions, with spring SD simulating terminal HS and reflecting regional farming practices. HS reduced days to flowering (DF), anthesis (DA), and maturity (DM) by 36-45%, shortened the grain-filling period (GFP), and decreased grain yield (GY) by ~25%, while key flour-quality traits (e.g., Zeleny index and grain hardness) remained stable under both SDs. Considerable genotypic variability was observed in both agronomic and quality traits. Stress tolerance and sensitivity indices (STI, MP, YSI, and HSI) were used to classify genotypes, with HSI identified as the most effective index due to its strong association with yield performance under HS. Several WAMI lines (e.g., 029, 123, 104, 067, and 139) demonstrated high yield potential combined with robust heat tolerance, as evidenced by their reduced yield loss under HS. These findings highlight the value of the WAMI panel for identifying heat-resilient wheat genotypes and providing critical insights for breeding programs targeting improved wheat performance under terminal HS and water-limited environments.

Understanding the concequence of drought stress memory and its interaction with genetic diversity and pollination system is critical for improving resilience in turf and forage grasses like tall fescue. With global warming and the predicted occurrence of frequent drought stresses in the future, little is known about these effects, especially on morphological traits, physiological responses, root characteristics, and spectral reflectance indices (SRIs). This study addresses the knowledge gap by evaluating the effects of drought memory in tall fescue using four parental clones (two drought-sensitive and two drought-tolerant), which were manually controlled to produce four selfed (S1) and four open-pollinated (OP) genotypes. Over two years, these genotypes were exposed to five moisture treatments: control (C), two treatments with twice applications of drought stress (primary mild drought stress in two different stages and secondary at the end stage, D1t1D2 and D1t2D2), one severe drought stress treatment (secondary only, D2), and foliar spray of salicylic acid (SA) under end-stage drought stress (H2D2). Selfing induced inbreeding depression, reducing relative water content (RWC), growth, chlorophyll, carotenoid content, catalase activity and root length. Alterations in natural plant mating systems can modify the genetic structure of tall fescue germplasm. Drought memory (D1t1D2 and D1t2D2) improved RWC, root-to-shoot ratio, and most physiological traits, especially pigment content, particularly in drought-tolerant and OP genotypes. SA treatment was more effective in mitigating drought effects in S1 than OP. Significant genetic variation in SRIs was observed, indicating their potential as predictive tools physiological traits. These findings provide insights into breeding strategies and highlight the importance of leveraging drought memory and genetic diversity to enhance drought resilience in tall fescue.

BACKGROUND: Introgression of wild alleles from the wild progenitor (Hordeum vulgare subsp. spontaneum) of cultivated barley (Hordeum vulgare L.) provides a powerful approach to expand genetic variation and enhance abiotic stress resilience. However, potential of wild barley germplasm for improving salinity tolerance in cultivated barley has not yet been fully explored. In this study, 21 wild accessions from various geographical regions were crossed with the cultivated cultivar ‘Ryhan03’. Through backcrossing and successive selfing, a Nested Backcross Population (NBP) comprising 443 advanced lines was developed. All lines along with parents were evaluated under both saline and normal field conditions across two growing seasons. RESULTS: Salinity had a significant impact on most traits, leading to a 32% reduction in grain yield (GY). The results revealed that genome introgression between different wild genotypes (as the foreground) within the common background of cultivated barley generated significant genetic variation. Furthermore, a high rate of transgressive segregation was observed for the measured traits and salinity tolerance in advanced recombinant inbred lines (RILs), indicating the potential presence of beneficial alleles lost during domestication. Wild parents originating from Iraq, Iran, and Turkmenistan were identified as promising genetic resources for improving key traits, particularly salinity tolerance, in cultivated barley. Superior recombinant inbred lines (RILs) were identified under both salinity and normal conditions: lines 287, 24, 283, 247, 293, 281, 223, 176, 158, and 8 exhibited exceptional performance under salinity stress, while lines 117, 5, 4, 281, 187, 112, 354, 421, 204, and 297 excelled under normal conditions. Additionally, lines 287, 190, 247, 293, 88, 158, 212, 24, 31, and 40 achieved the highest scores for Yield Stability Index (YSI) and Selection Index of Ideal Genotype (SIIG) across both treatments, highlighting their potential for developing new barley varieties suited for both saline and non-saline environments. CONCLUSION: This study demonstrated that wild barley is a rich reservoir of beneficial alleles for improving salinity tolerance in cultivated barley using nested populations. Wild parents and superior lines with transgressive segregation were identified in both normal and saline environments.

Background Genetic variation of regulatory alleles plays a key role in evolution and breeding. In polyploids, regulatory differences may preferentially affect genes on homoeologous chromosomes or sub-genomes. Selection in plant breeding may act upon total transcript dosage across homoeologous genes and on alleles that have strong effects on the transcriptome. Results To investigate these questions, we identified regulatory polymorphisms between an old and a recent hexaploid bread wheat cultivar ( Triticum aestivum , 2n=6x=42, AABBDD). The recent cultivar was the product of decades of selection for grain yield and quality. Regulatory allele polymorphisms preferentially affected genes on homoeologous chromosomes but rarely affected genes on specific sub-genomes. The chromosomal distributions of regulatory alleles indicated that past selection had acted upon them, and the effect of selection differed between alleles targeting environmental response genes and genes involved in other processes. Modern cultivar alleles that affected many genes’ transcripts corresponded to known selection targets and improved field crop performance. Modern cultivar alleles also had significant effects on homoeologous genes, and these alleles also improved crop performance. Conclusions Polyploid breeding across many species has been and will continue to be the key factor in plant improvement. By enhancing the favorability of strong regulatory alleles and by expanding the range of gene transcript abundances, genome duplications enable breeding progress. ### Competing Interest Statement The authors have declared no competing interest. * RNA-seq : RNA sequencing; SNP : Single Nucleotide Polymorphism cis-eQTL : cis-acting expression quantitative trait locus trans-eQTL : trans-acting expression quantitative trait locus UTR : Untranslated region DHLs : Doubled Haploid Lines TMM : trimmed mean of M-values FDR : false discovery rate GO : Gene Ontology BP : biological process SpikeL : spike length TKW : thousand kernel weight GA : gibberellin LASSO : Least Absolute Shrinkage and Selection Operator. Genome Canada, https://ror.org/029s29983 The Natural Sciences and Engineering Research Council of Canada

Salinity and water scarcity in arid and semi-arid regions pose significant challenges for turf-grass production and quality. The utilisation of salinity-tolerant turf grass genotypes is essential for enhancing their cultivation in both pasturelands and urban landscapes. Understanding the genetic variation of agro-morphological and turf quality characteristics, their associations, and the potential for simultaneous selection across forage and turf traits under salt stress conditions has not yet been thoroughly investigated in smooth bromegrass. In this study, 74 genotypes of smooth bromegrass (Bromus inermis L.) were assessed for forage, different agro-morphological, turf quality characteristics, and salt tolerance at five cuts in the field across 2 years of 2022 and 2023 under normal and salt stress conditions. Considerable genetic variation and estimate of heritability (h2b) were observed for measured traits under both conditions in the studied panel. The range of h2b was from 0.45 to 0.92 under normal and from 0.36 to 0.83 under salt stress conditions. Salt stress had an adverse effect on the forage yield (DFY), yield components and turf quality characteristics. On average, salt stress decreased the DFY, colour, coverage and density by about 50.78%, 6.73%, 32.20% and 34.54%, respectively. Under both conditions, the summer cut had the lowest values of forage production and turf quality characteristics compared to spring and autumn cuts, showing probable incomplete summer dormancy in the genotypes. Positive associations among crown diameter, plant height, leaf length, colour, coverage, density and stress tolerance index with forage yield indicated that simultaneous selection for both forage production and turf quality is feasible within this germplasm under both conditions. Based on the application of multivariate analysis, genotypes with possible utility as forage use or turf application were recognised, which can be used in future breeding programmes for developing synthetic varieties.

Spectral reflectance indices (SRIs) are increasingly recognized as valuable tools in wheat breeding programs for assessing traits that typically require destructive measurements. Little is known about the application of non‐descriptive methods in synthetic wheat and the effect of phenological stage. This study assessed variation and genetic parameters of SRIs and physiological parameters in a panel of synthetic wheat under both control and salinity conditions as well as the efficacy of SIR indices for selection across different phenological stages. Results indicated that salinity stress significantly reduced grain yield and relative water content while increasing ascorbate peroxidase (APX) enzyme activity across all growth stages. APX, peroxidase (POD), and the Green Difference Vegetation Index (GDVI) showed the highest heritability and genotypic coefficient of variation (GCV) across all phenological stages, suggesting strong genetic control over these indices. The Normalized Difference Vegetative Index (RNDVI) also demonstrated a similar trend under control conditions across all phenological stages. Principal Component Analysis (PCA) indicated that assessing SRIs concerning grain yield and physiological parameters was more effective during the anthesis and maturity stages than at milking. However, PCA effectively identified high‐yielding and salt‐tolerant genotypes during the milking stage, particularly at maturity. Overall, the SRIs analysis in wheat genotypes highlights their potential for optimizing selection timing and improving precision in breeding programs.

Tall fescue (Festuca arundinacea Schreb. syn. Lolium arundinaceum), an important cool-season grass, has limited understanding regarding its genetic inheritance patterns and the potential for simultaneous selection across forage, seed, and turf traits. In this study, 24 half-sib families derived from polycrosses, along with their corresponding parental genotypes, were assessed for different agro-morphological, seed, and turf quality characteristics in the field for 2 years (2019-2020). High genotypic variation was observed for all the measured traits. Moderate narrow-sense heritability (h2PFM) for turf quality and seed-related traits indicated that genetic variance predominates in total phenotypic variance of these traits. Low value of h2PFM (0.25) for dry forage yield (DFY) shows the high environmental influence on the expression of this economic trait. Indirect selection to improve DFY was more effective through its components, such as crown diameter (h2PFM = 0.43) and plant height (h2PFM = 0.48), which had higher heritability and positive correlation with forage yield. However, for seed and turf quality traits, direct selection would be possible during recurrent selection programs. The simultaneous selection for both forage yield and seed yield would be possible due to the positive correlation between them. Based on the application of multivariate analysis, parental genotypes and half-sib families with possible utility as forage and seed use or turf application were recognized, which can be used in the future breeding programs for developing synthetic varieties.

Salinity stress is a critical global constraint to wheat production, leading to significant yield reductions and deterioration in grain quality, particularly in arid and semi-arid regions such as Iran. The geographical distribution and salinity levels of soil resources vary across different regions of the country. Out of approximately 6.8 million hectares of salt-affected agricultural land in Iran, around 4.3 million hectares are constrained solely by salinity, posing no other major impediments to sustainable crop production. To address this challenge, advanced synthetic hexaploid wheat lines (SHW), created by combining novel and elite genes from tetraploid wheat (Triticum turgidum L.) and wild ancestors of goat grass (Aegilops tauschii), are proposed as high-potential germplasm for enhancing bread wheat (Triticum aestivum L.). SHW can introduce new genes (such as biotic and abiotic stresses) lost during common wheat evolution. However, concerns remain regarding the quality of synthetic wheat compared to conventional varieties. In the context of global warming and the challenges it presents for plant breeders, particularly in the predominantly arid and dry country like Iran, this study investigates such germplasm for the first time in the region. The aim is to evaluate the performance of a large and selected panel of synthetic hexaploid wheat lines (100 lines) alongside common wheat varieties (nine genotypes) focusing on quality traits, grain-related characteristics, and salt tolerance under various environmental conditions under two consecutive growing seasons. Wide variation and high heritability values were observed for most traits, indicating that the synthetic wheat (SHW) panel possesses valuable diversity for improving salt tolerance in wheat, and the expected gain from selection will be high due to the existing variation. The results showed that grain length (LEN), grain width (WID), grain diameter (DIA), 1000 grain weight (TGW), grain yield (GY), and zeleny sedimentation (ZEL) decreased significantly under salt stress conditions. The value of grain yield, LEN, WID, hardness (HARD), sodium carbonate solvent retention capacity (SCSRC), and sucrose solvent retention capacity (SuSRC) was higher for top 10% of SHW compared to common wheat under stress conditions. The results of correlation analysis indicated that grain yield has a negative correlation with protein content (PRO) and rapid mix test (RMT). Our findings suggest that synthetic wheats present a viable option for bread production compared to conventional wheat, owing to their enhanced resilience and productivity under climate change conditions. The result of this study identified superior genotypes suited for various future studies and the development of new salt-tolerance lines with favorable quality. The Solvent Retention Capacity (SRC) method, developed by Slade and Levine in 1994, is a well-recognized tool for predicting the quality of soft wheat. The AACC 56-11.02 (manual SRC profile) and 56-15.01 (automated SRC profile) are standard methods used for accurately measuring SRC values. The SRC methods had a strong potential to differentiate the quality of wheat genotypes. The superior genotypes identified in this study can be directly utilized or introgressed into wheat breeding programs as donor parents to enhance osmotic tolerance in elite germplasm.

The occurrence of drought stress memory in plants is crucial for their adaptation to adverse conditions. This research aimed to assess the genetic and physiological mechanisms of drought memory in tall fescue (Lolium arundinacea). A study was conducted with 22 open-pollinated and 11 selfed (S1) progenies over two years under three moisture regimes: control (C), mild-primary plus intense-secondary drought (D1D2), and intense-secondary drought (D2). Pre-exposure to drought (D1D2) significantly enhanced dry forage yield, plant height in recovery, root traits, chlorophyll content, and pigment ratios (P < 0.05), suggesting the presence of drought memory. Most root traits increased under D1D2 but declined under D2, with stronger memory responses in S1 lines. Selfing negatively affected several root and physiological traits under all moisture conditions. Additive gene action predominantly controlled root volume, root area, cumulative root length, and root-to-shoot ratio, with narrow-sense heritability estimates of 61.3–71.2

BACKGROUND:As climate change intensifies, perennial plants face more frequent drought periods throughout their lifespan. Drought stress memory in certain plants significantly enhances their adaptability to challenging environmental circumstances. However, in open-pollinated crops, this process is influenced by population plasticity due to the type and degree of genetic diversity, and inbreeding depression. To understand how pre-exposure to moderate drought enhances the plants' response to subsequent severe stresses, four synthetic poly-crossed populations were constructed using parents with contrasting molecular and morphological genetic variation (i.e. narrow and wide genetic distance). The first and second generations were subsequently assessed in an outdoor pot experiment at Isfahan University of Technology over two years, 2018 and 2019, under three different moisture conditions: Control with normal irrigation, DIDII underwent mild drought stress during the stem elongation phase followed, by severe drought stress during flowering, and DII subjected only to severe drought stress during flowering. RESULTS:Genotypes pre-exposed to DIDII treatment exhibited enhanced tolerance to subsequent severe drought compared to those exposed to DII treatment, indicating the importance of drought stress memory. However, trait-specific response observed for stress memory. The DIDII treatment improves dry matter yield, root volume, and root weight at different soil depths. Populations derived from parents with higher molecular and phenotypic variation were better suited for accurately predicting the performance of their progenies in terms of drought tolerance while not necessarily for stress memory. Inbreeding depression for root volume, root area, and root dry weight was affected by moisture conditions and the diversity level among the parental genotypes. CONCLUSION:Our research may pave the way for understanding the mechanisms behind drought stress memory in grasses, which can be exploited in future studies to develop synthetic varieties with improved drought tolerance through selective breeding using populations with diverse genetic backgrounds.

The genetic resources of wild barley (Hordeum vulgare ssp. spontaneum) may contain novel alleles for improving the abiotic stress tolerance of modern barley, including drought. To address this, a nested backcross population (NBP) was developed by crossing 21 wild barley accessions to the Ryhan03 cultivar, and the F1 progenies were backcrossed to Ryhan03 once. Parental accessions and 443 NBP developed lines were field evaluated for several agronomic traits and drought tolerance scores under well-watered and water-deficit treatments (40% and 85% soil water depletion, respectively) during 2017-2019, corresponding to the BC1F1, BC1F2, and BC1F3 generations. The NBP segregated for traits of interest, including grain yield, its components, and drought tolerance, indicating considerable potential for improving barley for grain yield and stress tolerance. For height and peduncle length, the population means were close to the value of wild parents. The mean values of grain yield for most families were higher than the wild parents and close to the value of Ryhan03. Favorable transgressive phenotypes occurred for grain yield and stress tolerance score, indicating the possibility of the genetic improvement of both traits simultaneously. Overall, wild parents P12, P13, P14, and P15 were identified as having utility for the genetic improvement of cultivated barley, including for drought tolerance. The NBP population offers an opportunity to explore the genetic potential of wild barley in an elite background for breeding.

Milk thistle (Silybum marianum L.) is highly valued for its medicinal properties. It is renowned for its capacity to flourish in dry environments, making it an attractive option for farming in areas with scarce water resources. This study aimed to assess how drought stress, foliar potassium sulfate application, and their interaction affect different milk thistle genotypes. Ten different genotypes (nine Iranian and one Hungarian) were assessed under three levels of soil water availability including control, moderate, and severe water stress, with depletion rates of 40%, 60%, and 80% of available water, respectively. Also, two foliar treatments were applied (non-spray and K2SO4 spray). Foliar K2SO4 application was applied twice, 7 days apart, during the flower bud development stage, using a 2% concentration in both 2020 and 2021. Drought stress adversely affected physiological parameters such as relative leaf water content and photosynthetic efficiency but enhanced antioxidant enzyme activities and osmotic adjustment mechanisms. K2SO4 foliar application exhibited dual effects, increasing yield while reducing key bioactive compounds including phenol and flavonoids content of seeds. Genotype-specific responses highlighted varying degrees of tolerance to drought stress and potassium application. Sari exhibited sensitivity to drought, while Isfahan and Hungary genotypes showed tolerance to moderate water stress with potassium foliar spray. Principal component analysis revealed the relationship of traits and genotypes by traits in each moisture condition. The study underscores the complexity of drought response mechanisms and the need for tailored management strategies and genotype selection to ensure resilience and optimize yield in milk thistle cultivation.

Synthetic hexaploid lines are proposed as high-potential germplasm for improving bread wheat by introducing new genes (biotic and abiotic stresses) lost during common wheat evolution. A panel of 99 synthetic and common wheat was studied for quality and grain-related traits and drought tolerance under two different moisture conditions (water stress and normal) during two growing seasons. Results indicated different variations for most traits suggesting that the synthetic hexaploid wheat-derived lines (SHW-DL) panel contains valuable genes for drought tolerance improvement of wheat. Drought stress reduced morphological traits and production but increased protein (Pro), rapid mix test (RMT), and solvent retention capacity (SRC) traits. Synthetic wheat lines were superior with higher grain yield, glutenin, damaged starch, available pentosane, overall water holding capacity, and gluten strength (glutenin and gliadin strength) compared to common wheat making them more suitable for bread-baking. The results showed that solvent retention capacity had a strong capacity to differentiate the quality of wheat genotypes. Correlation analysis indicated that genetic improvement for high-yielding varieties can be achieved by producing more damaged starch, higher water absorption, hardness, and lower gluten strength, and zeleny (ZEL). Selection of superior genotypes using univariate and multivariate methods will be discussed.

The identification of different plant genotypes, particularly during various developmental stages, is challenging due to the high genetic diversity of agricultural products. In this study, the efficacy of visible and infrared leaf spectroscopy in identifying five wheat genotypes was assessed across three main growth stages: leaf opening, tillering, and flowering. Soft independent modelling of class analogy (SIMCA) and artificial neural networks (ANN) were employed to develop growth-stage dependent and independent classification models based on spectral reflection. To handle the large amount of spectral data generated, a deep learning technique was first used to extract advanced features from the spectral data using the stacked autoencoder (SAE) approach. The results revealed that the tillering stage yielded the highest accuracy in predicting wheat genotypes when using the linear SIMCA approach. Furthermore, employing deep learning features extracted by SAE networks in the ANN classifier resulted in superior performance compared to the SIMCA classifier. During the leaf opening and tillering stages, the ANN classifier achieved perfect classification, with a weighted F1-score of 100 %, while during the flowering stage, it achieved a weighted F1-score of 98.02 %. In the combined dataset, the ANN classifier demonstrated impressive performance, with a weighted F1-score of 95.98 %. These findings suggest that in-field leaf spectroscopy techniques using deep learning feature extraction methods can be a suitable approach for identifying wheat plant genotypes during different growth stages.

This study aimed to investigate vetch genotypes' responses to moderate and severe drought stress and identify stress tolerance markers in arid conditions. Ten vetch genotypes (Vicia dassycarpa Ten., V. pannonica Crantz., V. michauxii Spereng., V. sativa-Ardebil, V. sativaDashtyar, V. sativa-Fereydonshahr, V. sativa-Mashhad, V. sativa-Semirom, V. sativaShahrekord and V. villosa Roth.) were cultivated under three water-deficit conditions: control, moderate and severe drought stress. These conditions represented maximum allowable depletion levels of 30, 50 and 85% of soil available water, applied after the six-leaf stage in the 2019-20 and 2020-21 growing seasons. The findings highlight the vetch's response to drought stress is influenced by stress severity and genotype. The result indicated a wide range of genetic diversity in agro-physiological traits among the studied vicia germplasm. Vicia dassycarpa Ten. shows highest straw yield and shorter days to flowering and maturity. Vicia michauxii Spreng. demonstrates high grain yield and advantageous traits like increased water content, photochemical efficiency of photosystem II, chlorophyll b, carotenoids and membrane stability index. It has lower soluble carbohydrate, DPPH (2,2-diphenyl-1-picrylhydrazyl) and pro- line content. Additionally, V. michauxii Spreng. exhibits superior agronomic traits such as more seeds per pod, per plant and higher 1000 seeds weight, serving as reliable markers for drought tolerance. The results emphasize V. dassycarpa Ten. for fodder and V. michauxii Spreng. for grain production in water-limited regions. Further research on gene expression related to drought tolerance traits should enhance our understanding of vetch.