Drought Stress In Wheat Research Articles

Stress-Responsive Gene Expression, Metabolic, Physiological, and Agronomic Responses by Consortium Nano-Silica with Trichoderma against Drought Stress in Bread Wheat

The exploitation of drought is a critical worldwide challenge that influences wheat growth and productivity. This study aimed to investigate a synergistic amendment strategy for drought using the single and combined application of plant growth-promoting microorganisms (PGPM) (Trichoderma harzianum) and biogenic silica nanoparticles (SiO2NPs) from rice husk ash (RHA) on Saudi Arabia’s Spring wheat Summit cultivar (Triticum aestivum L.) for 102 DAS (days after sowing). The significant improvement was due to the application of 600 ppm SiO2NPs and T. harzianum + 600 ppm SiO2NPs, which enhanced the physiological properties of chlorophyll a, carotenoids, total pigments, osmolytes, and antioxidant contents of drought-stressed wheat plants as adaptive strategies. The results suggest that the expression of the studied genes (TaP5CS1, TaZFP34, TaWRKY1, TaMPK3, TaLEA, and the wheat housekeeping gene TaActin) in wheat remarkably enhanced wheat tolerance to drought stress. We discovered that the genes and metabolites involved significantly contributed to defense responses, making them potential targets for assessing drought tolerance levels. The drought tolerance indices of wheat were revealed by the mean productivity (MP), stress sensitivity index (SSI), yield stability index (YSI), and stress tolerance index (STI). We employed four databases, such as BAR, InterPro, phytozome, and the KEGG pathway, to predict and decipher the putative domains in prior gene sequencing. As a result, we discovered that these genes may be involved in a range of important biological functions in specific tissues at different developmental stages, including response to drought stress, proline accumulation, plant growth and development, and defense response. In conclusion, the sole and/or dual T. harzianum application to the wheat cultivar improved drought tolerance strength. These findings could be insightful data for wheat production in Saudi Arabia under various water regimes.

Hyperspectral Imaging for Phenotyping Plant Drought Stress and Nitrogen Interactions Using Multivariate Modeling and Machine Learning Techniques in Wheat

Accurate detection of drought stress in plants is essential for water use efficiency and agricultural output. Hyperspectral imaging (HSI) provides a non-invasive method in plant phenotyping, allowing the long-term monitoring of plant health due to sensitivity to subtle changes in leaf constituents. The broad spectral range of HSI enables the development of different vegetation indices (VIs) to analyze plant trait responses to multiple stresses, such as the combination of nutrient and drought stresses. However, known VIs may underperform when subjected to multiple stresses. This study presents new VIs in tandem with machine learning models to identify drought stress in wheat plants under varying nitrogen (N) levels. A pot wheat experiment was set up in the glasshouse with four treatments: well-watered high-N (WWHN), well-watered low-N (WWLN), drought-stress high-N (DSHN) and drought-stress low-N (DSLN). In addition to ensuring that plants were watered according to the experiment design, photosynthetic rate (Pn) and stomatal conductance (gs) (which are used to assess plant drought stress) were taken regularly, serving as the ground truth data for this study. The proposed VIs, together with known VIs, were used to train three classification models: support vector machines (SVM), random forest (RF), and deep neural networks (DNN) to classify plants based on their drought status. The proposed VIs achieved more than 0.94 accuracy across all models, and their performance further increased when combined with known VIs. The combined VIs were used to train three regression models to predict the stomatal conductance and photosynthetic rates of plants. The random forest regression model performed best, suggesting that it could be used as a stand-alone tool to forecast gs and Pn and track drought stress in wheat. This study shows that combining hyperspectral data with machine learning can effectively monitor and predict drought stress in crops, especially in varying nitrogen conditions.

Abscisic acid improves drought resilience, growth, physio-biochemical and quality attributes in wheat (Triticum aestivum L.) at critical growth stages

Wheat is an important staple crop not only in Pakistan but all over the globe. Although the area dedicated to wheat cultivation expands annually, the quantity of wheat harvested is declining due to various biotic and abiotic factors. Global wheat production and output have suffered as a result of the drought, which is largely driven by a lack of water and environmental factors. Organic fertilizers have been shown to reduce the severity of drought. The current research was conducted in semi-arid climates to mitigate the negative effects of drought on wheat during its critical tillering (DTS), flowering (DFS), and grain filling (DGFS) stages through the application of three different abscisic acid treatments: ABA0 (0 mgL−1) control, ABA1 (100 mgL−1) and ABA2 (200 mgL−1). Wheat growth and yield characteristics were severely harmed by drought stress across all critical development stages, with the DGFS stage being particularly vulnerable and leading to a considerable loss in yield. Plant height was increased by 24.25%, the number of fertile tillers by 25.66%, spike length by 17.24%, the number of spikelets per spike by 16.68%, grain count per spike by 11.98%, thousand-grain weight by 14.34%, grain yield by 26.93% and biological yield by 14.55% when abscisic acid (ABA) was applied instead of the control treatment. Moreover, ABA2 increased the more physiological indices (water use efficiency (36.12%), stomatal conductance (44.23%), chlorophyll a (24.5%), chlorophyll b (29.8%), transpiration rate (23.03%), photosynthetic rate (24.84%), electrolyte leakage (− 38.76%) hydrogen peroxide (− 18.09%) superoxide dismutase (15.3%), catalase (20.8%), peroxidase (− 18.09%), and malondialdehyde (− 13.7%)) of drought-stressed wheat as compared to other treatments. In the case of N, P, and K contents in grain were maximally improved with the application of ABA2. Through the use of principal component analysis, we were able to correlate our results across scales and provide an explanation for the observed effects of ABA on wheat growth and production under arid conditions. Overall, ABA application at a rate of 200 mgL−1 is an effective technique to boost wheat grain output by mitigating the negative effects of drought stress.

PGPR isolated from hot spring imparts resilience to drought stress in wheat (Triticum aestivum L.)

Drought is a major abiotic stress that occurs frequently due to climate change, severely hampers agricultural production, and threatens food security. In this study, the effect of drought-tolerant PGPRs, i.e., PGPR-FS2 and PGPR-VHH4, was assessed on wheat by withholding water. The results indicate that drought-stressed wheat seedlings treated with PGPRs-FS2 and PGPR-VHH4 had a significantly higher shoot and root length, number of roots, higher chlorophyll, and antioxidant enzymatic activities of guaiacol peroxidase (GPX) compared to without PGPR treatment. The expression study of wheat genes related to tryptophan auxin-responsive (TaTAR), drought-responsive (TaWRKY10, TaWRKY51, TaDREB3, and TaDREB4) and auxin-regulated gene organ size (TaARGOS-A, TaARGOS-B, and TaARGOS-D) exhibited significantly higher expression in the PGPR-FS2 and PGPR-VHH4 treated wheat under drought as compared to without PGPR treatment. The results of this study illustrate that PGPR-FS2 and PGPR-VHH4 mitigate the drought stress in wheat and pave the way for imparting drought in wheat under water deficit conditions. Among the two PGPRs, PGPR-VHH4 more efficiently altered the root architecture to withstand drought stress.

TaMYB-CC5 gene specifically expressed in root improve tolerance of phosphorus deficiency and drought stress in wheat

Phosphate deficiency and drought are significant environmental constraints that impact both the productivity and quality of wheat. The interaction between phosphorus and water facilitates their mutual absorption processes in plants. Under conditions of both phosphorus deficiency and drought stress, we observed a significant upregulation in the expression of wheat MYB-CC transcription factors through the transcriptome analysis. 52 TaMYB-CC genes in wheat were identified and analyzed their evolutionary relationships, structures, and expression patterns. The TaMYB-CC5 gene exhibited specific expression in roots and demonstrated significant upregulation under phosphorus deficiency and drought stress compared to other TaMYB-CC genes. The overexpression of TaMYB-CC5A in Arabidopsis resulted in a significant increase of root length under stress conditions, thereby enhancing tolerance to phosphate starvation and drought stress. The wheat lines with silenced TaMYB-CC5 genes exhibited reduced root length under stress conditions and increased sensitivity to phosphate deficiency and drought stress. In addition, silencing the TaMYB-CC5 genes resulted in altered phosphorus content in leaves but did not lead to a reduction in phosphorus content in roots. Enrichment analysis the co-expression genes of TaMYB-CC5 transcription factors, we found the zinc-induced facilitator-like (ZIFL) genes were prominent associated with TaMYB-CC5 gene. The TaZIFL1, TaZIFL2, and TaZIFL5 genes were verified specifically expressed in roots and regulated by TaMYB-CC5 transcript factor. Our study reveals the pivotal role of the TaMYB-CC5 gene in regulating TaZIFL genes, which is crucial for maintaining normal root growth under phosphorus deficiency and drought stress, thereby enhanced resistance to these abiotic stresses in wheat.

Drought stress in wheat: mechanisms, effects and mitigation through vermicompost

Drought stress in wheat: mechanisms, effects and mitigation through vermicompost

Amelioration of drought stress in wheat by using plant growth-promoting rhizobacteria and biogas slurry

<p>Drought stress has a significant impact on cereal-based staple food production, particularly in developing countries like Pakistan. To ensure a sustainable and reliable food supply, it is essential to develop comprehensive production plans that incorporate various approaches to mitigate the effects of drought. In a study conducted using a randomized complete block design, we investigated the potential of plant growth-promoting rhizobacteria (PGPR) and biogas Slurry (BGs) either individually or in combination to alleviate drought stress at different stages of wheat growth. The two-year field research demonstrated that the application of Azosprillium lipoferum with biogas slurry resulted in improved water relations, chlorophyll content, grain quality, yield, and related characteristics in wheat plants compared to the stressed treatments. Particularly, the combined treatment of PGPR and BGs exhibited the most favorable outcomes. Notably, the combined treatment effectively mitigated drought stress by significantly increasing antioxidant levels (17% APX, 29% POD, 34% CAT, and 41% SOD) during the grain-filling stage (GFS) compared to the controls. The combined treatment resulted in a remarkable 40% improvement in the respective controls at the GFS stage. Overall, the combined use of PGPR and BGs was identified as an effective strategy to enhance the resilience of wheat plants to drought, particularly in arid and semi-arid regions.</p>

Amelioration of drought stress in wheat by using plant growth-promoting rhizobacteria and biogas slurry

Amelioration of drought stress in wheat by using plant growth-promoting rhizobacteria and biogas slurry

An auxin regulated Universal stress protein (TaUSP_3B-1) interacts with TaGolS and provides tolerance under drought stress and ER stress.

A previously identified wheat drought stress responsive Universal stress protein, TaUSP_3B-1 has been found to work in an auxin dependent manner in the plant root tissues in the differentiation zone. We also found a novel interacting partner, TaGolS, which physically interacts with TaUSP_3B-1 and colocalizes in the endoplasmic reticulum. TaGolS is a key enzyme in the RFO (Raffinose oligosaccharides) biosynthesis which is well reported to provide tolerance under water deficit conditions. TaUSP_3B-1 overexpression lines showed an early flowering phenotype under drought stress which might be attributed to the increased levels of AtTPPB and AtTPS transcripts under drought stress. Moreover, at the cellular levels ER stress induced TaUSP_3B-1 transcription and provides tolerance in both adaptive and acute ER stress via less ROS accumulation in the overexpression lines. TaUSP_3B-1 overexpression plants had increased silique numbers and a denser root architecture as compared to the WT plants under drought stress.

Transgenerational Seed Exposure to Elevated CO2 Involves Stress Memory Regulation at Metabolic Levels to Confer Drought Resistance in Wheat.

Drought is the worst environmental stress constraint that inflicts heavy losses to global food production, such as wheat. The metabolic responses of seeds produced overtransgenerational exposure to e[CO2] to recover drought's effects on wheat are still unexplored. Seeds were produced constantly for four generations (F1 to F4) under ambient CO2 (a[CO2], 400 μmol L-1) and elevated CO2 (e[CO2], 800 μmol L-1) concentrations, and then further regrown under natural CO2 conditions to investigate their effects on the stress memory metabolic processes liable for increasing drought resistance in the next generation (F5). At the anthesis stage, plants were subjected to normal (100% FC, field capacity) and drought stress (60% FC) conditions. Under drought stress, plants of transgenerational e[CO2] exposed seeds showed markedly increased superoxide dismutase (16%), catalase (24%), peroxidase (9%), total antioxidants (14%), and proline (35%) levels that helped the plants to sustain normal growth through scavenging of hydrogen peroxide (11%) and malondialdehyde (26%). The carbohydrate metabolic enzymes such as aldolase (36%), phosphoglucomutase (12%), UDP-glucose pyrophosphorylase (25%), vacuolar invertase (33%), glucose-6-phosphate-dehydrogenase (68%), and cell wall invertase (17%) were decreased significantly; however, transgenerational seeds produced under e[CO2] showed a considerable increase in their activities in drought-stressed wheat plants. Moreover, transgenerational e[CO2] exposed seeds under drought stress caused a marked increase in leaf Ψw (15%), chlorophyll a (19%), chlorophyll b (8%), carotenoids (12%), grain spike (16%), hundred grain weight (19%), and grain yield (10%). Hence, transgenerational seeds exposed to e[CO2] upregulate the drought recovery metabolic processes to improve the grain yield of wheat under drought stress conditions.

Effects of Selenium on DNA Methylation and Genomic Instability Induced by Drought Stress in Wheat (Triticum aestivum L.)

The main purpose of the study was to clarify the effect of selenium (Se) on DNA damage and DNA methylation in wheat (Triticum aestivum L.) plants exposed to polyethylene glycol (PEG)-induced drought stress under in vitro tissue culture. Random amplified polymorphic DNA (RAPD) and coupled restriction enzyme digestion-random amplification (CRED-RA) were utilized to explain the DNA damage grade and variations in DNA methylation patterns, respectively. The outcomes indicate that drought stress gives rise to a rise in RAPD profile variations (as DNA damage) and a decrease in genomic template stability (GTS) rate and DNA methylation changes. According to the RAPD data, the greatest GTS value was computed at 56.9% (5% PEG 6000), and the lowest GTS value was 41.2% (15% PEG 6000), demonstrating the adverse effects of PEG 6000. However, DNA damage can be reduced by treatment with sodium selenate (2, 4, and 6 µM of Na2SeO4) together with PEG (5%, 10%, and 15% PEG 6000)-induced water deficits. Moreover, according to CRED-RA analysis, PEG-induced DNA methylation rates were changed after treating different doses of Se. These data demonstrate that Se dose-dependently modulates both DNA damage and methylation alterations induced by drought in wheat.

Identification of Genotypes Tolerant to Drought Stress in Wheat using Quantitative Indices in Different Regions of Iran's Cold Climate

Identification of Genotypes Tolerant to Drought Stress in Wheat using Quantitative Indices in Different Regions of Iran's Cold Climate

Breeding for water-use efficiency in wheat: progress, challenges and prospects.

Drought poses a significant challenge to wheat production globally, leading to substantial yield losses and affecting various agronomic and physiological traits. The genetic route offers potential solutions to improve water-use efficiency (WUE) in wheat and mitigate the negative impacts of drought stress. Breeding for drought tolerance involves selecting desirable plants such as efficient water usage, deep root systems, delayed senescence, and late wilting point. Biomarkers, automated and high-throughput techniques, and QTL genes are crucial in enhancing breeding strategies and developing wheat varieties with improved resilience to water scarcity. Moreover, the role of root system architecture (RSA) in water-use efficiency is vital, as roots play a key role in nutrient and water uptake. Genetic engineering techniques offer promising avenues to introduce desirable RSA traits in wheat to enhance drought tolerance. These technologies enable targeted modifications in DNA sequences, facilitating the development of drought-tolerant wheat germplasm. The article highlighted the techniques that could play a role in mitigating drought stress in wheat.

Nitrogen mitigates the negative effects of combined heat and drought stress on winter wheat by improving physiological characteristics.

Extreme drought stress is often accompanied by heat stress after anthesis in winter wheat. Whether nitrogen (N) can mitigate the damage caused by combined stress on wheat plants by regulating root physiological characteristics is still unclear. Thus, this study aimed to study the effects of combined heat and drought stress on photosynthesis, leaf water relations, root antioxidant system, osmoregulatory, and yield in wheat to reveal the physiological mechanism of N regulating the adverse impacts of combined stress on wheat. Heat and drought stress markedly reduced photosynthesis, leaf water content, root vitality, and bleeding sap. The combination of heat and drought strengthens these changes. Within a certain stress range, the increase in soluble sugar and proline contents and the activities of superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase under combined stress effectively alleviated the oxidative damage. Compared with those under high N application (N3), wheat plants under low N application (N1) maintained higher yield and yield components under combined stress; the number of grains per spike, 1000-grain weight, and yield increased by 13.65%, 9.07%, and 15.33%, respectively, under N1 compared with those under N3 treatment, which may be attributed to the greater maintenance of photosynthesis, leaf water status, root vitality, and antioxidant and osmoregulation capacities. In summary, reduced N application mitigated the damage caused by combined heat and drought stress in wheat by improving root physiological characteristics and enhanced adaptability to combined stress, which is an appropriate strategy to compensate for yield losses.

Active oxygen generation induced by the glucose sensor TaHXK7-1A decreased the drought resistance of transgenic Arabidopsis and wheat (Triticum aestivum L.)

Improving wheat drought resistance is of great significance for grain production and food security. Hexokinases (HXKs) play a role in sugar signal transduction and are involved in abiotic stress responses in wheat. To clarify the relationship between HXKs and drought stress in wheat, we used the rice active oxygen induction gene OsHXK1 as a reference sequence and the homologously cloned wheat TaHXK7-1A gene. TaHXK7-1A was localized in the nucleus and cell membrane. Under drought stress, over-expression of TaHXK7-1A increased the contents of O2·－ and malondialdehyde (MDA) and significantly up-regulated the respiratory burst oxidative homologue (RBOHs) genes in transgenic Arabidopsis. In addition, the over-expression of TaHXK7-1A inhibited the growth of Arabidopsis seedlings and increased ROS accumulation under 6 % exogenous glucose treatment. Gene silencing of TaHXK7-1 decreased the contents of O2·－ and MDA in wheat leaves under drought stress, and the RBOHs was significantly down-regulated, which improved the drought resistance of wheat. The results of yeast one-hybrid, EMSA, and dual-luciferase assays showed that TabHLH148-5A bound to the E-box motif of the TaHXK7-1A promoter and inhibited the expression of TaHXK7-1A. In addition, yeast two-hybrid and luciferase complementation imaging assays showed that TaHXK7-1A interacted with TaGRF3-4A. These results indicate that the glucose sensor TaHXK7-1A was negatively regulated by TabHLH148-5A, interacted with TaGRF3-4A, and negatively regulated wheat drought resistance by regulating RBOHs expression and inducing ROS production, thus providing a theoretical basis for revealing the molecular mechanism of wheat drought resistance.

Drought Stress and its Tolerance Mechanism in Wheat

Plants encounter diverse forms of stress in response to fluctuations in their surrounding environment. Drought is a very detrimental environmental stressor that negatively impacts crop Plants. The phenomenon of drought stress in Plants is characterized by its intricate nature, arising from many environmental factors, including limited soil water availability, elevated soil salinity levels, and increased ambient temperature. The latter is referred to as physiological drought. The wheat plant exhibits high sensitivity to dry conditions, particularly during the flowering and grain-filling stages. The phenomenon led to a significant decline in the growth and production of wheat crops. Water stress during crucial growth stages, including tillering, grain filling, and flowering, has been identified as a significant factor leading to substantial reductions in crop output. Drought stress in wheat induces morphological, physiological, biochemical, and molecular alterations. Plants employ three fundamental survival strategies, stress avoidance, escape, and tolerance, in response to drought-induced stress. The cultivation of drought-tolerant cultivars and the implementation of agronomic practices play a crucial role in the development of novel water-use strategies for effective drought management. Drought tolerance is a multifaceted characteristic governed by multiple genes, with their expressions modulated by diverse environmental factors. Therefore, the challenge of breeding for this particular trait is considerable, necessitating the utilization of novel molecular techniques such as molecular markers, quantitative trait loci [QTL] mapping procedures, and gene expression patterns to generate genotypes that exhibit tolerance to drought conditions. Wheat possesses multiple genes that contribute to drought stress tolerance by encoding various enzymes and proteins, such as late embryogenesis abundant [LEA], abscisic acid-responsive [RAB], rubisco, helicase, proline, glutathione-S-transferase [GST], and carbohydrates, which are involved in mitigating the effects of drought stress. This review paper has focused on examining the impact of water limitation on several aspects of wheat, including its morphology, physiology, biochemistry, and molecular responses. Additionally, it explores the potential losses incurred by wheat due to drought-induced stress.

Vermicompost application upregulates morpho-physiological and antioxidant defense to conferring drought tolerance in wheat

Drought stress is an ever‐present threat to wheat growth, development, and productivity, especially in arid and semi-arid areas where rainfall is an essential aid to agriculture. The application of vermicompost has been proven to be an efficient approach to combat the drought-induced growth and developmental limitation of wheat plants and to promote cost-effective and sustainable crop production. A wire-house pot experiment was conducted to examine the effects of cow manure vermicompost on morpho-physiological and biochemical attributes of wheat seedlings under different deficit water levels. The treatments were included: three drought levels; control (70 % of field capacity (FC, D0)), mild drought (45 % of FC, D1), and severe drought (30 % of FC, D1), four vermicompost application rates; control, 4, 6 and 8 t ha−1 (designated as VT0, VT1, VT2 and VT3, respectively), and two contrasting wheat cultivars; Faisalabad-08 (drought tolerant) and Galaxy-13 (drought sensitive). Results showed that vermicompost application improved crop performance under control and drought stress conditions where VT2 depicted significantly higher values in both cultivars, particularly under drought stress. Under severe drought, VT2 increased root fresh weight by 6.13 and 10.63 %, shoot fresh weight by 15.62 % and 23.58 %, root dry weight by 40.81 % and 50 % and shoot dry weight by 20.68 and 22.22 % in Faisalabad-08 and Galaxy-13, respectively. Also, VT2-treated seedlings exhibited significantly higher gas exchange attributes, chlorophyll pigments and antioxidative enzyme activities under drought conditions. Among cultivars, Faisalabad-08 was found comparatively more drought tolerant than Galaxy-13. Our findings demonstrated that drought severely affects morphological, physiological, and biochemical attributes of wheat. However, soil applied vermicompost proved beneficial for improved morphophysiological and biochemical traits under the regime of drought stress in wheat.

QTL mapping: insights into genomic regions governing component traits of yield under combined heat and drought stress in wheat.

Drought and heat frequently co-occur during crop growth leading to devastating yield loss. The knowledge of the genetic loci governing component traits of yield under combined drought and heat stress is essential for enhancing the climate resilience. The present study employed a mapping population of 180 recombinant inbred lines (RILs) derived from a cross between GW322 and KAUZ to identify quantitative trait loci (QTLs) governing the component traits of yield under heat and combined stress conditions. Phenotypic evaluation was conducted across two consecutive crop seasons (2021-2022 and 2022-2023) under late sown irrigation (LSIR) and late sown restricted irrigation (LSRI) conditions at the Indian Council of Agricultural Research Institute-Indian Agricultural Research Institute (ICAR-IARI), New Delhi. Various physiological and agronomic traits of importance were measured. Genotyping was carried out with 35K SNP Axiom breeder's genotyping array. The linkage map spanned a length of 6769.45cM, ranging from 2.28cM/marker in 1A to 14.21cM/marker in 5D. A total of 35 QTLs were identified across 14 chromosomes with 6B containing the highest (seven) number of QTLs. Out of 35 QTLs, 16 were major QTLs explaining the phenotypic variance greater than 10%. The study identified eight stable QTLs along with two hotspots on chromosomes 6B and 5B. Five QTLs associated with traits thousand-grain weight (TGW), normalized difference vegetation index (NDVI), and plant height (PH) were successfully validated. Candidate genes encoding antioxidant enzymes, transcription factors, and growth-related proteins were identified in the QTL regions. In silico expression analysis highlighted higher expression of transcripts TraesCS2D02G021000.1, TraesCS2D02G031000, TraesCS6A02G247900, and TraesCS6B02G421700 under stress conditions. These findings contribute to a deeper understanding of the genetic architecture underlying combined heat and drought tolerance in wheat, providing valuable insights for wheat improvement strategies under changing climatic conditions.

Early Detection of Drought Stress in Durum Wheat Using Hyperspectral Imaging and Photosystem Sensing

Wheat, being the third largest U.S. crop and the principal food grain, faces significant risks from climate extremes such as drought. This necessitates identifying and developing methods for early water-stress detection to prevent yield loss and improve water-use efficiency. This study investigates the potential of hyperspectral imaging to detect the early stages of drought stress in wheat. The goal is to utilize this technology as a tool for screening and selecting drought-tolerant wheat genotypes in breeding programs. Additionally, this research aims to systematically evaluate the effectiveness of various existing sensors and methods for detecting early stages of water stress. The experiment was conducted in a durum wheat experimental field trial in Maricopa, Arizona, in the spring of 2019 and included well-watered and water-limited treatments of a panel of 224 replicated durum wheat genotypes. Spectral indices derived from hyperspectral imagery were compared against other plant-level indicators of water stress such as Photosystem II (PSII) and relative water content (RWC) data derived from proximal sensors. Our findings showed a 12% drop in photosynthetic activity in the most affected genotypes when compared to the least affected. The Leaf Water Vegetation Index 1 (LWVI1) highlighted differences between drought-resistant and drought-susceptible genotypes. Drought-resistant genotypes retained 43.36% more water in leaves under well-watered conditions compared to water-limited conditions, while drought-susceptible genotypes retained only 15.69% more. The LWVI1 and LWVI2 indices, aligned with the RWC measurements, revealed a strong inverse correlation in the susceptible genotypes, underscoring their heightened sensitivity to water stress in earlier stages. Several genotypes previously classified based on their drought resistance showed spectral indices deviating from expectations. Results from this research can aid farmers in improving crop yields by informing early management practices. Moreover, this research offers wheat breeders insights into the selection of drought-tolerant genotypes, a requirement that is becoming increasingly important as weather patterns continue to change.

Soil Manuring and Genetic Variation Conjunctively Surmount the Partial Drought Stress in Wheat (Triticum aestivum L.)

Crop growth is negatively influenced under water-stress conditions, which is among the most yield-limiting factors significantly decreasing crop yield. This study evaluated the effect of water-deficit stress on physiological, bio-chemical and yield attributes of wheat (Triticum aestivum L.) under both constantly wet and water-stressed conditions on two wheat varieties (UJALA-14, SARC-4). Further, the combined impacts of crop genetic variability and organic manuring in soil was studied for overcoming the partial drought stress in wheat. Treatments of different levels of irrigation water alone or with farmyard manure (FYM) @ 20 Mg ha‒1 were compared as: constantly wet irrigation (control), irrigation intensity equal to field capacity (FC), ½ FC + FYM, and ¼ FC + FYM. Crop growth, physiological and chlorophyll as well as sodium and potassium contents were measured. The findings of current study exhibited that shortage of water had negative effects on growth, physiological, bio-chemical and yield attributes of wheat. Genotype SARC-4 exhibited superior growth response having constantly wet and field capacity condition, on the other hand UJALA-14 gave better growth response under water stress conditions of ½ FC and ¼ FC when treated with FYM amendment. It is concluded that partial drought stress developed tolerance in wheat genotypes particularly in UJALA-14, which was strengthened with organic amendment. Combined use of drought tolerant varieties and application of FYM as a fertilizer is very effective way to enhance crop yield.