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Introduction: Drought is one of the major limitation on food production worldwide (Hu et al., 2020), which is a growing problem caused by an increasing world population. In wheat cultivation in the Mediterranean climate, mainly the stages of flowering and grain filling are exposed with drought stress. Drought stress reduces the yield of wheat in all growth stages, but its negative effect on grain yield is very severe in the stages of flowering and grain filling. Terminal drought and moisture stress are the main factors of wheat yield reduction under rainfed condition compared to irrigation conditions in Iran. Therefore, one solution to increase the yield is the breeding under drought stress conditions. Due to the low heritability of yield and the complex mechanisms of drought tolerance, little progress has been made in wheat grain yield under drought conditions. Therefore, the grain yield of wheat should be improved indirectly through improving the traits that greatly affect grain yield. Therefore, it seems necessary to identify the quantity and quality of relationships between different traits and grain yield under rainfed conditions. The use of multivariate statistical methods such as path analysis and canonical correlation analysis can help to identify important and effective traits in determining seed yield. This research was carried out with the aim of finding effective agronomical traits on yield and investigating the relationship between these traits and physiological traits under rainfed conditions. Materials and methods: In order to determine the effective trait on wheat grain yield under rainfed conditions and investigate the relationship between agronomic and physiological traits, an experiment was conducted with 21 lines along with Baran, Hashtroud and Sardari cultivars as control in the form of a randomized complete blocks design in four replications during two years at Khodabande Rainfed Research Station. Plant height (PLH), Day to Heading (DHE), Day to physiological maturity (DMA) at the same time as peduncle yellowing, 1000 grain weight and yield after physiological maturity were measured. To determine the variability between the studied genotypes, descriptive parameters and compound variance analysis were performed based on the expected of mean square, the effects of year and replication was randomly considered and the effect of genotype as a fixed effect using SAS (9.4) software. Simple correlation analysis, path analysis and canonical correlation analysis were used to determine the relationship between traits and to determine effective traits. Results and discussion: ANOVA showed significant difference between genotypes in terms of all studied traits. Simple correlation analysis showed 19 significant correlation and other correlation were not significant. There is a positive and significant correlation between grain yield and Photosynthesis rate, height and 1000-grain weight, but the relationship between day to heading and grain yield was negative and significant. Path analysis revealed that day-to-heading and day-to-maturity traits with -1.05 and 0.84 had the most direct and negative direct effects on grain yield, respectively. Canonical correlation analysis also showed a significant canonical correlation (r = 0.74) between the set of physiological traits and agronomic traits. According to the results of this study, it was found that agronomic traits of day to heading, day to maturity and height are effective in determining grain yield under dryland conditions. Conclusion: The investigation of the relationship between traits also showed that selection for physiological traits such as transpiration rate and lower stomatal conductance led to selection of genotypes with high height, low day to heading and shorter growth period and finally higher yield under rainfed conditions.Therefore, genotypes with shorter growth periods that can escape terminal-season stresses and lose less water by closing stomata are suitable for high yields under rainfed conditions. [ABSTRACT FROM AUTHOR]

Purpose: Continuous positive airway pressure (CPAP) is the primary therapy for obstructive sleep apnea (OSA); however the effectiveness of CPAP remains suboptimal. We describe the Novel PhysIologiC prEdictors of Positive Airway Pressure Effectiveness (NICEPAP) study. Its purpose is to determine whether physiological traits of OSA contribute to CPAP effectiveness. Methods: NICEPAP (NCT05067088) is a prospective, observational cohort study conducted at an academic sleep center. Adults newly diagnosed with OSA (n = 267) are assessed for OSA traits of loop gain, arousal threshold, pharyngeal collapsibility, and muscle compensation from baseline polysomnography. We perform a comprehensive assessment of covariates relevant to CPAP adherence, efficacy, and patient-centered outcomes. Participants are followed for 12 months. Primary outcomes include (1) CPAP adherence (hours/night), (2) CPAP efficacy (apneas-hypopneas/hour), and (3) quality of life at six months measured by objective CPAP data and Functional Outcomes of Sleep Questionnaire. Secondary outcomes include sleep quality, sleepiness, insomnia, and neurocognitive function. Results: Data on covariates, including demographics, sleep symptoms, medical history, medications, sleep quality, OSA and treatment self-efficacy, decisional balance, and socio-economic and social and partner support, are collected using validated instruments. The analysis for primary outcomes includes a generalized linear mixed model for an outcome (e.g., CPAP adherence) with OSA traits as exposures followed by the addition of relevant covariates. Conclusion: The findings of the NICEPAP study will inform research aimed to enhance CPAP effectiveness. Understanding the role of physiological OSA traits in CPAP effectiveness is a crucial step toward a precision medicine approach to OSA. [ABSTRACT FROM AUTHOR]

Various biological traits support the invasive success of different organisms. The osmoregulatory capacity and food preferences of the signal crayfish Pacifastacus leniusculus were experimentally tested to determine if they contribute to its invasive success. The osmotic concentrations of haemolymph were determined after acclimation of the crustaceans to seven salinities from 0 to 20 PSU. Food preferences were tested using Canadian pondweed Elodea canadensis, and rainbow trout Oncorhynchus mykiss. The results showed that the signal crayfish exhibits a hyper-hypoosmotic regulation pattern in the salinity range from 0 to 20 PSU, enabling them to inhabit both freshwater and brackish environments. Furthermore, the study found signal crayfish to have non-specific food preferences, although fish muscle tissue is more beneficial as a source of energy. Both features, osmoregulatory ability and food preferences, can increase the invasive success of this species as it expands into new areas. The ability to survive in higher salinities compared to the coastal waters of the Baltic Sea along the Polish coastline should be considered in targeted management strategies to control the spread of this invasive species. [ABSTRACT FROM AUTHOR]

Fertilization significantly affects the growth and development of wheat. However, the precise mechanisms underlying gene regulation during flowering in response to fertilization deficiency remain elusive. In this study, fertilization (F) and non-fertilization (CK)) treatments were set up to reveal examine the effect of fertilization on the photosynthetic capacity of winter wheat during the flowering period through physiological, biochemical, and transcriptome analyses. Upon analyzing analysing their yield, leaf photosynthetic system exchange parameters during flowering, antioxidant enzyme activity, and endogenous hormone parameters, we found that the F treatment resulted in higher net photosynthetic rates during flowering periods than the CK treatment. The superoxide dismutase (SOD) (83.92%), peroxidase (POD) (150.75%), and catalase (CAT) (22.74%) activities of leaves in treated with F during the flowering period were notably elevated compared to those of CK-treated leaves. Abscisic acid (ABA) (1.86%) and gibberellin acid (GA3) (33.69%) levels were reduced, whereas Auxin auxin (IAA) (98.27%) content was increasedwas increased under F treatment compared to those the results under the CK treatment. The chlorophyll a (32.53%), chlorophyll b (56%), total chlorophyll (37.96%), and carotenoid contents (29.80%) under F treatment were also increased compared to CK., exceeded exceeding those obtained under the CK treatment. Furthermore, transcriptional differences between the F and CK conditions were analyzed, and key genes were screened and validated by using q-PCR. Transcriptome analysis identified 2281 differentially expressed genes (DEGs), with enriched pathways related to photosynthesis and light harvesting. DEGs were subjected to cluster simulation, which revealed that 53 DEGS, both up- and down-regulated, responded to the F treatment. qRT-PCR-based validation confirmed the differential expression of genes associated with carbohydrate transport and metabolism, lipid transport, and signal transduction. This study revealed distinctive transcriptional patterns and crucial gene regulation networks in wheat during flowering under fertilization, providing transcriptomic guidance for the precise regulation of wheat breeding. [ABSTRACT FROM AUTHOR]

The vulnerability of commercial crops under a changing climate has led scientists to consider wild crop species as alternative food sources. The aim of this study was to identify plastic physiological and morphological traits that could be used to in vitro screen Amaranthus dubius and Galinsoga parviflora seeds for drought, salinity, and heat tolerance. To establish the lethal dose/temperature, 50% (LD/T50), for each stress, seeds for both were subjected to various mannitol and NaCl stresses and a range of temperatures. Percentage seedling emergence was selected as the initial indicator of tolerance and used to establish the LD/T50 for in vitro screening for both species. Seeds of both were then screened at the LD/T50 concentrations/temperatures established, and seedlings that emerged after 21 days were measured for leaf area, root (RL), shoot length (SL), chlorophyll content (Chl), fresh, dry mass, and leaf number. Data for these were used to quantify plasticity in terms of Valladares's phenotypic plasticity index. For A. dubius, three (viz. RL, SL, and Chl) showed some plasticity (≥0.53) and tolerance across all three stressors. For G. parviflora all traits except SL showed some plasticity (≥0.58) and tolerance across all three stressors. Both species had high phenotypic plasticity across all three stressors, which suggests that wild leafy vegetables may possess the ability to tolerate climate change-associated stressors and should be considered for future breeding programs. [ABSTRACT FROM AUTHOR]

Abstract Background Sustainable crop production along with best nutrient use efficiency is the key indicator of smart agriculture. Foliar application of plant nutrients can complement soil fertilization with improved nutrient uptake, translocation and utilization. Recent developments in slow releasing, nano-fertilizers in agriculture, begins a new era for sustainable use and management of natural resources. This study aims to explore the effectiveness of nano-nitrogen usage on plant growth, yield attributes and sustaining rice production while optimizing fertilizer N application through conventional (prilled urea) and nano-N source under salt stress conditions. Results The strategic substitutions of traditional urea by nano-nitrogen was distributed from partial to complete with 33, 50, 66 and 100% applications. Further, the strategic substitutions were compared in saline (ECe ∼ 6.0 dSm− 1) and sodic stress (pH ∼ 9.1) conditions along with normal soils to dissect the beneficial response of nano-N in two rice varieties (CSR 30 and PB 1121). Salt stress affected the plant performance by decreasing leaf relative water content upto 10%, total chlorophyll content by 1.3–1.5%, leaf area upto 29.9%, gas exchange attributes by 10–39%, with concomitant yield reductions upto ∼ 4%. Collateral improvement in leaf greenness (SPAD index) crop growth rate and net assimilation rate was observed with foliar application of Nano-N. 0.2–1.64% enhancement in growth traits, 0.93–1.85% in physiological traits, and comparable yield gains with 100% recommended dose of prilled were comparative with nano-substitutions. Salt tolerant rice variety, CSR-30 performed better than PB 1121 with better expression of morphological, physiological and yield traits under stress conditions and nitrogen substitutions. Conclusions Overall, our experimental findings revealed agricultural use of nano-N in improving the plant physiological efficiency and optimizing rice yields with partial N substitution through nano fertilizers under salt stress conditions. These studies are further open for futuristic aspects of long term effects of nano-fertilizers on soil nutrient depletion in correlation to yield enhancement in salt affected soils.

The vulnerability of commercial crops under a changing climate has led scientists to consider wild crop species as alternative food sources. The aim of this study was to identify plastic physiological and morphological traits that could be used to in vitro screen Amaranthus dubius and Galinsoga parviflora seeds for drought, salinity, and heat tolerance. To establish the lethal dose/temperature, 50% (LD/T50), for each stress, seeds for both were subjected to various mannitol and NaCl stresses and a range of temperatures. Percentage seedling emergence was selected as the initial indicator of tolerance and used to establish the LD/T50 for in vitro screening for both species. Seeds of both were then screened at the LD/T50 concentrations/temperatures established, and seedlings that emerged after 21 days were measured for leaf area, root (RL), shoot length (SL), chlorophyll content (Chl), fresh, dry mass, and leaf number. Data for these were used to quantify plasticity in terms of Valladares’s phenotypic plasticity index. For A. dubius, three (viz. RL, SL, and Chl) showed some plasticity (≥0.53) and tolerance across all three stressors. For G. parviflora all traits except SL showed some plasticity (≥0.58) and tolerance across all three stressors. Both species had high phenotypic plasticity across all three stressors, which suggests that wild leafy vegetables may possess the ability to tolerate climate change-associated stressors and should be considered for future breeding programs.

IntroductionDrought is one of the major limitation on food production worldwide (Hu et al., 2020), which is a growing problem caused by an increasing world population. In wheat cultivation in the Mediterranean climate, mainly the stages of flowering and grain filling are exposed with drought stress. Drought stress reduces the yield of wheat in all growth stages, but its negative effect on grain yield is very severe in the stages of flowering and grain filling. Terminal drought and moisture stress are the main factors of wheat yield reduction under rainfed condition compared to irrigation conditions in Iran. Therefore, one solution to increase the yield is the breeding under drought stress conditions. Due to the low heritability of yield and the complex mechanisms of drought tolerance, little progress has been made in wheat grain yield under drought conditions. Therefore, the grain yield of wheat should be improved indirectly through improving the traits that greatly affect grain yield. Therefore, it seems necessary to identify the quantity and quality of relationships between different traits and grain yield under rainfed conditions. The use of multivariate statistical methods such as path analysis and canonical correlation analysis can help to identify important and effective traits in determining seed yield. This research was carried out with the aim of finding effective agronomical traits on yield and investigating the relationship between these traits and physiological traits under rainfed conditions.Materials and methodsIn order to determine the effective trait on wheat grain yield under rainfed conditions and investigate the relationship between agronomic and physiological traits, an experiment was conducted with 21 lines along with Baran, Hashtroud and Sardari cultivars as control in the form of a randomized complete blocks design in four replications during two years at Khodabande Rainfed Research Station. Plant height (PLH), Day to Heading (DHE), Day to physiological maturity (DMA) at the same time as peduncle yellowing, 1000 grain weight and yield after physiological maturity were measured. To determine the variability between the studied genotypes, descriptive parameters and compound variance analysis were performed based on the expected of mean square, the effects of year and replication was randomly considered and the effect of genotype as a fixed effect using SAS (9.4) software. Simple correlation analysis, path analysis and canonical correlation analysis were used to determine the relationship between traits and to determine effective traits.Results and discussionANOVA showed significant difference between genotypes in terms of all studied traits. Simple correlation analysis showed 19 significant correlation and other correlation were not significant. There is a positive and significant correlation between grain yield and Photosynthesis rate, height and 1000-grain weight, but the relationship between day to heading and grain yield was negative and significant. Path analysis revealed that day-to-heading and day-to-maturity traits with -1.05 and 0.84 had the most direct and negative direct effects on grain yield, respectively. Canonical correlation analysis also showed a significant canonical correlation (r = 0.74) between the set of physiological traits and agronomic traits. According to the results of this study, it was found that agronomic traits of day to heading, day to maturity and height are effective in determining grain yield under dryland conditions.ConclusionThe investigation of the relationship between traits also showed that selection for physiological traits such as transpiration rate and lower stomatal conductance led to selection of genotypes with high height, low day to heading and shorter growth period and finally higher yield under rainfed conditions.Therefore, genotypes with shorter growth periods that can escape terminal-season stresses and lose less water by closing stomata are suitable for high yields under rainfed conditions.

Abstract The impact of biochar application on plant performance under drought stress necessitates a comprehensive understanding of biochar–soil interaction, root growth, and plant physiological processes. Therefore, pot experiments were conducted to assess the effects of biochar on plant responses to drought stress at the seedling stage. Two contrasting maize genotypes (drought-sensitive KN5585 vs. -tolerant Mo17) were subjected to biochar application under drought stress conditions. The results indicated that biochar application decreased soil exchangeable Na+ and Ca2+ contents while increased soil exchangeable K+ content (2.7-fold) and electrical conductivity (4.0-fold), resulting in an elevated leaf sap K+ concentration in both maize genotypes. The elevated K+ concentration with biochar application increased root apoplastic pH in the drought-sensitive KN5585, but not in the drought-tolerant Mo17, which stimulated the activation of H+-ATPase and H+ efflux in KN5585 roots. Apoplast alkalinization of the drought-sensitive KN5585 resulting from biochar application further inhibited root growth by 30.7%, contributing to an improvement in water potential, a reduction in levels of O2 –, H2O2, T-AOC, SOD, and POD, as well as the down-regulation of genes associated with drought resistance in KN5585 roots. In contrast, biochar application increased leaf sap osmolality and provided osmotic protection for the drought-tolerant Mo17, which was associated with trehalose accumulation in Mo17 roots. Biochar application improved sucrose utilization and circadian rhythm of Mo17 roots, and increased fresh weight under drought stress. This study suggests that biochar application has the potential to enhance plant drought tolerance, which is achieved through the inhibition of root growth in sensitive plants and the enhancement of osmotic protection in tolerant plants, respectively. Graphical Abstract

Extended Abstract Background: As one of the most important cereals, bread wheat is an essential part of food security in the world, which supplies one-fifth of the total calories of the world population. Nowadays, the yield of wheat has been affected by climate change-driven drought as one of the most important abiotic stresses that has become an important threat to food security in the world. Root and stomatal traits are especially important in breeding plants to withstand drought stress. Stomata play a key role in controlling carbon dioxide uptake and water loss through transpiration. Therefore, stomatal characteristics are used as indicators of water status and plant growth, especially in drought stress conditions. Having a wide range of physiological and morphological characteristics, roots play an essential role in absorbing water and nutrients. They are also the first organ that sends signals to control the stomata in response to dryness. Therefore, the difference in the structure of the root system can cause the difference between the performance in different cultivars. This study was conducted to investigate stomatal characteristics and their relationship with the root system and plant performance in 24 bread wheat lines and cultivars. Methods: To investigate the relationship between stomatal dimensions and density with the root system, an experiment was conducted on 24 bread wheat genotypes in the form of a randomized complete block design with three replications in the rainfed conditions of the research farm at Zanjan University Faculty of Agriculture in the crop year 2018-2019. In this experiment, PVC pipes were used to study the root system. Twelve seeds were planted in each tube, which were thinned to seven after germination. In each experimental unit, there were two tubes for each genotype, one of which was used to evaluate traits and final yield, and the second tube was used for root studies. Stomatal traits, including the length and width of stomata and number of stomata per unit area, root traits including root length, root diameter, root volume, root surface, and root biomass, and seed yield were measured in the end. The resulting data from the measured traits were analyzed in the form of a randomized complete block design, and the averages were compared using the LSD method. The data were analyzed using multivariate statistical analyses, including regression analysis, path analysis, and factor analysis, and cluster analysis was used to group genotypes. Statistical calculations were done using SAS 9.0 and SPSS 21 software. Results: The results of analysis of variance and mean comparison showed high variability among genotypes for all measured traits. The results of the mean comparison of genotypes showed that genotypes 2, 5, 8, and 16 had the highest yield, and genotype 23 had the lowest yield among the examined genotypes. The highest number of stomata on the upper and lower leaf surfaces belonged to genotypes 5 and 2. In terms of root traits, the highest diameter, volume, length, root surface, and root dry weight at a depth of 0-25 cm were recorded for genotypes 2, 3, 18, and 5, respectively. There was a high and significant correlation between the yield and the number of stomata on the upper and lower leaf surfaces, the length and width of the stomata on the upper leaf surface, diameter, volume, dry weight, and root surface at a depth of 0-25 cm in the soil. Based on the results of stepwise regression analysis, two variables, the number of stomata on the lower leaf surface and root dry weight at a depth of more than 25 cm explained 91.4% of the changes in grain yield. According to the results of the causality analysis of the number of stomata on the lower leaf surface, the most direct effect had a positive effect on seed yield. The results of factor analysis grouped the studied traits into three factors with 82.48% variability justification. The shares of the first, second, and third factors to explaining data changes were 48.86%, 24.62%, and 8.99%, respectively. Based on the plot obtained from factor analysis, genotypes 2, 5, 8, and 16 had high values for the first and second factors. According to the coefficients of the factors, it can be claimed that the genotypes located in this area have high performance, a high number of stomata, and strong root traits, which were found at the soil depth of 0-25 cm. For this reason, these are the genotypes that could produce high yields by absorbing water from the surface layers of the soil by having a large number of stomata and carrying out more photosynthesis. Moreover, the investigated genotypes were divided into three groups from cluster analysis by the ward method and Euclidean distance. Genotypes 2, 5, 8, and 16 were placed in the first group and had the highest mean values for grain yield traits, number and width of stomata on the upper and lower leaf surfaces, and root traits including diameter, volume, and dry weight at a soil depth of 0-25 cm, and root diameter at a depth greater than 25 cm. The lowest values for stomatal length were observed in both leaf surfaces. These were the best genotypes for cultivation in dry conditions. Conclusion: A strong superficial root system can provide the plant with water from scattered rains that occur with low frequency at the end of the growth period. On the other hand, the increase in the number of stomata along with their smaller size reduces leaf pores and enables a faster response of the stomata, and the rapid response of the stomata maximizes water use efficiency. Therefore, having a strong superficial root system along with high stomatal density can increase seed yield in dry conditions.

Rice (Oryza sativa L.) plant architecture is crucial in rice productivity enhancement, particularly in forecasting agronomic-related traits. The presented research characterized the shoot architecture, photosynthesis, and yield-related traits in the F9 generation of rice recombinant inbred lines (RILs) derived from a cross between cultivar IR64 and local cultivar Hawara Bunar through correlation and path analyses among the various features. Rice RILs and parental cultivars’ sowing transpired in the greenhouse and the field. The greenhouse experiment commenced growing the rice seeds of 90 RILs and their parental lines in PVC tubes (20 cm in diameter and 50 cm in height) with sand soil as a medium. The study employed the upland rice cultivation system for the field experiment to cultivate the rice genotypes. The study used a randomized complete block design (RCBD) with three replications. Shoot plant architecture, physiological, and yield traits observation continued at various stages of plant growth. A significant positive correlation to the seed yield per plant appeared in the maturative stage by the total seed weight, transpiration efficiency, intercellular CO2 concentration, and intercellular CO2 pressure. A substantial positive indirect effect on grain yield also surfaced from the net transpiration rate and its efficiency, intercellular CO2 concentration, and CO2 pressure. Therefore, the shoot architecture significantly affects the photosynthetic rate and grain yield. [ABSTRACT FROM AUTHOR]

The impact of biochar application on plant performance under drought stress necessitates a comprehensive understanding of biochar–soil interaction, root growth, and plant physiological processes. Therefore, pot experiments were conducted to assess the effects of biochar on plant responses to drought stress at the seedling stage. Two contrasting maize genotypes (drought-sensitive KN5585 vs. -tolerant Mo17) were subjected to biochar application under drought stress conditions. The results indicated that biochar application decreased soil exchangeable Na+ and Ca2+ contents while increased soil exchangeable K+ content (2.7-fold) and electrical conductivity (4.0-fold), resulting in an elevated leaf sap K+ concentration in both maize genotypes. The elevated K+ concentration with biochar application increased root apoplastic pH in the drought-sensitive KN5585, but not in the drought-tolerant Mo17, which stimulated the activation of H+-ATPase and H+ efflux in KN5585 roots. Apoplast alkalinization of the drought-sensitive KN5585 resulting from biochar application further inhibited root growth by 30.7%, contributing to an improvement in water potential, a reduction in levels of O2–, H2O2, T-AOC, SOD, and POD, as well as the down-regulation of genes associated with drought resistance in KN5585 roots. In contrast, biochar application increased leaf sap osmolality and provided osmotic protection for the drought-tolerant Mo17, which was associated with trehalose accumulation in Mo17 roots. Biochar application improved sucrose utilization and circadian rhythm of Mo17 roots, and increased fresh weight under drought stress. This study suggests that biochar application has the potential to enhance plant drought tolerance, which is achieved through the inhibition of root growth in sensitive plants and the enhancement of osmotic protection in tolerant plants, respectively. Biochar application decreased soil exchangeable Na+ and Ca2+, but increased soil exchangeable K+ and electrical conductivity. Biochar increased apoplastic pH, but reduced root growth, stress damage and stress response during drought for the drought-sensitive KN5585. Biochar improved osmotic protection, trehalose accumulation, and fresh weight during drought for the drought-tolerant Mo17. [ABSTRACT FROM AUTHOR]

Background: As one of the most important cereals, bread wheat is an essential part of food security in the world, which supplies one -fifth of the total calories of the world population. Nowadays, the yield of wheat has been affected by climate change -driven drought as one of the most important abiotic stresses that has become an important threat to food security in the world. Root and stomatal traits are especially important in breeding plants to withstand drought stress. Stomata play a key role in controlling carbon dioxide uptake and water loss through transpiration. Therefore, stomatal characteristics are used as indicators of water status and plant growth, especially in drought stress conditions. Having a wide range of physiological and morphological characteristics, roots play an essential role in absorbing water and nutrients. They are also the first organ that sends signals to control the stomata in response to dryness. Therefore, the difference in the structure of the root system can cause the difference between the performance in different cultivars. This study was conducted to investigate stomatal characteristics and their relationship with the root system and plant performance in 24 bread wheat lines and cultivars. Methods: To investigate the relationship between stomatal dimensions and density with the root system, an experiment was conducted on 24 bread wheat genotypes in the form of a randomized complete block design with three replications in the rainfed conditions of the research farm at Zanjan University Faculty of Agriculture in the crop year 2018 -2019. In this experiment, PVC pipes were used to study the root system. Twelve seeds were planted in each tube, which were thinned to seven after germination. In each experimental unit, there were two tubes for each genotype, one of which was used to evaluate traits and final yield, and the second tube was used for root studies. Stomatal traits, including the length and width of stomata and number of stomata per unit area, root traits including root length, root diameter, root volume, root surface, and root biomass, and seed yield were measured in the end. The resulting data from the measured traits were analyzed in the form of a randomized complete block design, and the averages were compared using the LSD method. The data were analyzed using multivariate statistical analy ses, including regression analysis, path analysis, and factor analysis, and cluster analysis was used to group genotypes. Statistical calculations were done using SAS 9.0 and SPSS 21 software. Results: The results of analysis of variance and mean comparison showed high variability among genotypes for all measured traits. The results of the mean comparison of genotypes showed that genotypes 2, 5, 8, and 16 had the highest yield, and genotype 23 had the lowest yield among the examined genotypes. The highest number of stomata on the upper and lower leaf surface s belonged to genotypes 5 and 2. In terms of root traits, the highest diameter, volume, length, root surface, and root dry weight at a depth of 0 -25 cm were recorded for genotypes 2, 3, 18, and 5, respectively. There was a high and significant correlation between the yield and the number of stomata on the upper and lower leaf surface s, the length and width of the stomata on the upper leaf surface, diameter, volume, dry weight, and root surface at a depth of 0 -25 cm in the soil. Based on the results of stepwise regression analysis, two variables, the number of stomata on the lower leaf surface and root dry weight at a depth of more than 25 cm explained 91.4% of the changes in grain yield. According to the results of the causality analysis of the number of stomata on the lower leaf surface, the most direct effect had a positive effect on seed yield. The results of factor analysis grouped the studied traits into three factors with 82.48% variability justification. The share s of the first, second, and third facto r s to explaining data changes were 48.86%, 24.62%, and 8.99%, respectively. Based on the plot obtained from factor analysis, genotypes 2, 5, 8, and 16 had high values for the first and second factors. According to the coefficients of the factors, it can be claimed that the genotypes located in this area have high performance, a high number of stomata, and strong root traits, which were found at the soil depth of 0 -25 cm. For this reason, these are the genotypes that could produce high yields by absorbing water from the surface layers of the soil by having a large number of stomata and carrying out more photosynthesis. Moreover, the investigated genotypes were divided into three groups from cluster analysis by the ward method and Euclidean distance. Genotypes 2, 5, 8, and 16 were placed in the first group and had the highest mean values for grain yield traits, number and width of stomata on the upper and lower leaf surfaces, and root traits including diameter, volume, and dry weight at a soil depth of 0 - 2 5 cm, and root diameter at a depth greater than 25 cm. The lowest values for stomatal length were observed in both leaf surfaces. These were the best genotypes for cultivation in dry conditions. Conclusion: A strong superficial root system can provide the plant with water from scattered rains that occur with low frequency at the end of the growth period. On the other hand, the increase in the number of stomata along with their smaller size reduces leaf pores and enables a faster response of the stomata, and the rapid response of the stomata maximizes water use efficiency. Therefore, having a strong superficial root system along with high stomatal density can increase seed yield in dry conditions. [ABSTRACT FROM AUTHOR]

Cotton is a pivotal global commodity underscored by its economic value and widespread use. In the face of climate change, breeding resilient cultivars for variable environmental conditions becomes increasingly essential. However, the process of phenotyping, crucial to breeding programs, is often viewed as a bottleneck due to the inefficiency of traditional, low-throughput methods. To address this limitation, this study utilizes hyperspectral remote sensing, a promising tool for assessing crucial crop traits across forty cotton varieties. The results from this study demonstrated the effectiveness of four vegetation indices (VIs) in evaluating these varieties for water-use efficiency (WUE). The prediction accuracy for WUE through VIs such as the simple ratio water index (SRWI) and normalized difference water index (NDWI) was higher (up to R2 = 0.66), enabling better detection of phenotypic variations (p < 0.05) among the varieties compared to physiological-related traits (from R2 = 0.21 to R2 = 0.42), with high repeatability and a low RMSE. These VIs also showed high Pearson correlations with WUE (up to r = 0.81) and yield-related traits (up to r = 0.63). We also selected high-performing varieties based on the VIs, WUE, and fiber quality traits. This study demonstrated that the hyperspectral-based proximal sensing approach helps rapidly assess the in-season performance of varieties for imperative traits and aids in precise breeding decisions. [ABSTRACT FROM AUTHOR]

Drought and salinity are two abiotic stresses that affect plant productivity. We exposed 2-year-old Platycladus orientalis saplings to single and combined stress of drought and salinity. Subsequently, the responses of physiological traits and soil properties were investigated. Biochemical traits such as leaf and root phytohormone content significantly increased under most stress conditions. Single drought stress resulted in significantly decreased nonstructural carbohydrate (NSC) content in stems and roots, while single salt stress and combined stress resulted in diverse response of NSC content. Xylem water potential of P. orientalis decreased significantly under both single drought and single salt stress, as well as the combined stress. Under the combined stress of drought and severe salt, xylem hydraulic conductivity significantly decreased while NSC content was unaffected, demonstrating that the risk of xylem hydraulic failure may be greater than carbon starvation. The tracheid lumen diameter and the tracheid double wall thickness of root and stem xylem was hardly affected by any stress, except for the stem tracheid lumen diameter, which was significantly increased under the combined stress. Soil ammonium nitrogen, nitrate nitrogen and available potassium content was only significantly affected by single salt stress, while soil available phosphorus content was not affected by any stress. Single drought stress had a stronger effect on the alpha diversity of rhizobacteria communities, and single salt stress had a stronger effect on soil nutrient availability, while combined stress showed relatively limited effect on these soil properties. Regarding physiological traits, responses of P. orientalis saplings under single and combined stress of drought and salt were diverse, and effects of combined stress could not be directly extrapolated from any single stress. Compared to single stress, the effect of combined stress on phytohormone content and hydraulic traits was negative to P. orientalis saplings, while the combined stress offset the negative effects of single drought stress on NSC content. Our study provided more comprehensive information on the response of the physiological traits and soil properties of P. orientalis saplings under single and combined stress of drought and salt, which would be helpful to understand the adapting mechanism of woody plants to abiotic stress. [ABSTRACT FROM AUTHOR]

The foliar application of nutrients and plant growth regulators (PGRs) at critical crop growth periods can improve the yield of field crops. Hence, the present study was conducted to quantify the effects of the combined application of nutrients and PGRs (crop-specific formulation) on maize, blackgram, greengram, groundnut, cotton, sugarcane, and coconut yield. In all the crops except coconut, the treatments included (i) a foliar spray of crop-specific nutrients and PGR combinations and (ii) an unsprayed control. In coconut, the treatments included (i) the root feeding of coconut-specific nutrients and PGR combinations and (ii) an untreated control. Crop-specific nutrient and PGR formulations were sprayed, namely, Tamil Nadu Agricultural University (TNAU) maize maxim 1.5% at the tassel initiation and grain-filling stages of maize, TNAU pulse wonder 1.0% at the peak flowering stage of green gram and black gram, TNAU groundnut-rich 1.0% at the flowering and pod-filling stages of groundnut, TNAU cotton plus 1.25% at the flowering and boll development stages of cotton, and TNAU sugarcane booster 0.5% at 45 days after planting (DAP), 0.75% at 60 DAP, and 1.0% at 75 DAP of sugarcane. The results showed that the foliar application of TNAU maize maxim, TNAU pulse wonder, TNAU groundnut-rich, TNAU cotton plus and TNAU sugarcane booster and the root feeding of TNAU coconut tonic increased the yield of maize, pulses, groundnut, cotton, sugarcane, and coconut, resulting in higher economic returns. [ABSTRACT FROM AUTHOR]

This study investigates the role of abscisic acid (ABA) in bolstering drought resistance in plants, employing "Panjiang Sophora viciifolia" as the subject. A simulated drought scenario was created using polyethylene glycol (PEG-6000) to examine the impact of varying drought intensities (0%, 5%, 20% PEG) and ABA concentrations (0, 10, 50, 100, 200 mg·L−1) on the germination and physiological parameters of Sophora viciifolia. The results showed that in the absence of ABA, the germination rate (GR), germination potential (GP), and germination index (GI) of S. viciifolia seeds initially increased and then decreased with escalating PEG-induced drought stress. At PEG-induced drought stress levels of 5% and 20%, the activities of peroxidase (POD) and catalase (CAT), along with the malondialdehyde (MDA) content, were significantly higher than in the control (CK) (p < 0.05). In response to drought stress, S. viciifolia seeds adapted by modulating germination behavior, augmenting the content of osmoregulatory substances, and boosting the activity of protective enzymes. The addition of ABA markedly enhanced GR, GE, GI, activities of POD, superoxide dismutase (SOD), and CAT, as well as the levels of MDA and proline (Pro) under drought conditions (p < 0.05). Relative to CK, low ABA concentrations (10–100 mg·L−1) resulted in increased GR, GP, GI, POD, SOD, CAT, MDA, and Pro levels; whereas, at a higher concentration (200 mg·L−1), although GR, GP, and GI decreased, POD, SOD, CAT, MDA, and Pro levels increased. Through principal component analysis and membership function comprehensive evaluation, it was determined that administering 50 mg·L−1 ABA was most effective in enhancing drought resistance in S. viciifolia seedlings. [ABSTRACT FROM AUTHOR]

Key message: This study not only provide a theoretical basis for screening drought-resistant yellowhorn rootstocks but also lay the foundation for the research on the drought resistance mechanism of yellowhorn. Drought is a major limiting factor in the production and cultivation of yellowhorn, an important woody oil species in China. It is important to select excellent drought-resistant rootstocks, and the current reproduction of rootstocks of yellowhorn is mainly through seed propagation. In this study, we analyzed the phenotypes, physiology and anatomy of the F1 generation of five yellowhorn varieties ('Zhongshi 1', 'Zhongshi 4', 'Zhongshi 7', 'Zhongshi 9' and 'Yuanda') which are currently the main promoted varieties of yellowhorn. The changes in physiological traits were used to comprehensively rank drought resistance by the membership function method. The results showed that the drought resistance of different varieties was in the order 'Zhongshi 9' > 'Zhongshi 4' > 'Yuanda' > 'Zhongshi 7' > 'Zhongshi 1'. In addition, we investigated the molecular signature of two yellowhorn varieties exhibiting a large difference in levels of drought resistance using transcriptome data. A total of 119 differentially expressed genes (DEGs) were found between the 2 yellowhorn varieties under drought stress. Based on KEGG analysis, DEGs were mostly enriched in three pathways. According to the correlation analysis between weighted gene co-expression network analysis (WGCNA) and physiological traits, a total of four co-expression networks with high correlation were constructed, and some hub genes of yellowhorn in response to drought stress were found. We carried out a comprehensive evaluation of yellowhorn drought tolerance based on parental lines. It solves the current problems faced in the breeding of yellowhorn and lays the foundation for studying the molecular mechanism of drought resistance in yellowhorn. [ABSTRACT FROM AUTHOR]

In order to explore the response mechanism of Passiflora edulis Sims to drought stress, the changes in morphological and physiological traits of Passiflora edulis Sims under different drought conditions were studied. A total of 7 germplasm resources of Passiflora edulis Sims were selected and tested under drought stress by the pot culture method under 4 treatment levels: 75%-80% (Control, CK) of maximum field water capacity, 55%-60% (Light Drought, LD) of maximum field water capacity, i.e., mild drought, 40%-45% (Moderate Drought, MD) of maximum field water capacity, i.e., moderate drought and 30%-35% (Severe Drought, SD) of maximum field water capacity, i.e., severe drought. On the 40th day of drought treatment, 13 indices, including seedling growth morphology, physiology, and biochemistry, were measured. The results showed that under drought stress, the height and ground diameter of P. edulis Sims gradually decreased with increasing drought stress, and there were significant differences in seedling height and ground diameter among the treatments. Drought stress significantly inhibited the growth of seven P. edulis Sims varieties. The contents of soluble sugar (SS), soluble protein (SP), proline (Pro), and other substances in P. edulis Sims basically increased with increasing drought stress. With the aggravation of drought stress, the malondialdehyde (MDA) content of P. edulis Sims tended to increase to different degrees, the superoxide dismutase (SOD) activity and peroxidase (POD) activity both tended to increase at first and then decrease, and the change in catalase (CAT) activity mostly showed a gradual increasing trend. The contents of endogenous hormones in P. edulis Sims significantly differed under different degrees of drought stress. With the aggravation of drought stress, the abscisic acid (ABA) content of P. edulis Sims tended to increase, whereas the contents of gibberellin (GA), indoleacetic acid (IAA), and zeatin nucleoside (ZR) exhibited a downward trend. A comprehensive evaluation of the drought resistance of seven P. edulis Sims varieties was conducted based on the principal component analysis method, and the results showed that the drought resistance decreased in the order XH-BL > XH-TWZ > TN1 > GH1 > ZJ-MT > LP-LZ > DH-JW. [ABSTRACT FROM AUTHOR]

Cultivating stevia is imperative because it is a natural sweetener, providing a healthier and low-calorie substitute for sugar. A comprehensive study was undertaken in 2021-2022, employing a randomized complete block design with three replicates, to evaluate the growth, yield, physiological, and biochemical characteristics of stevia across diverse Iranian climates (Arak, Rasht, Gorgan, Hamedan, Isfahan, Kermanshah, Shiraz, Tabriz, Tehran, and Urmia). The findings unveiled notable variations in growth, yield, physiological, biochemical traits, and steviol glycoside content among different cultivation sites. Notably, Shiraz, Isfahan, Tehran, and Arak exhibited the highest leaf yield, recording values of 119.89, 91.25, 97.07, and 86.24 g m-2, respectively. Conversely, Rasht and Gorgan showcased the lowest growth and yield parameters. Of particular interest, Shiraz samples displayed the highest photosynthetic pigment content (chlorophyll) and the lowest proline levels. Rasht samples demonstrated the highest average content of rebaudioside-A, stevioside, and total steviol glycosides (3.01%, 8.66%, and 11.67%, respectively). Furthermore, Shiraz samples yielded the most steviol glycosides at 122.6 mg m-2. Correlation analysis between climatic data and yield, along with biochemical traits, indicated positive associations of average temperature, rainfall, and relative humidity with leaf yield and steviol glycoside content. In contrast, altitude exhibited a negative correlation with steviol glycoside content. In conclusion, Shiraz is recommended for stevia cultivation for optimal growth and leaf yield, while Rasht and Gorgan are preferable for steviol glycoside production. [Fundam Appl Agric 2024; 9(2.000): 122-130]

Abstract Nitrogen (N) is an essential element for plant growth, and its deficiency influences plants at several physiological and gene expression levels. Barley (Hordeum vulgare) is one of the most important food grains from the Poaceae family and one of the most important staple food crops. However, the seed yield is limited by a number of stresses, the most important of which is the insufficient use of N. Thus, there is a need to develop N-use effective cultivars. In this study, comparative physiological and molecular analyses were performed using leaf and root tissues from 10 locally grown barley cultivars. The expression levels of nitrate transporters, HvNRT2 genes, were analyzed in the leaf and root tissues of N-deficient (ND) treatments of barley cultivars after 7 and 14 days following ND treatment as compared to the normal condition. Based on the correlation between the traits, root length (RL) had a positive and highly significant correlation with fresh leaf weight (FLW) and ascorbate peroxidase (APX) concentration in roots, indicating a direct root and leaf relationship with the plant development under ND. From the physiological aspects, ND enhanced carotenoids, chlorophylls a/b (Chla/b), total chlorophyll (TCH), leaf antioxidant enzymes such as ascorbate peroxidase (APX), peroxidase (POD), and catalase (CAT), and root antioxidant enzymes (APX and POD) in the Sahra cultivar. The expression levels of HvNRT2.1, HvNRT2.2, and HvNRT2.4 genes were up-regulated under ND conditions. For the morphological traits, ND maintained root dry weight among the cultivars, except for Sahra. Among the studied cultivars, Sahra responded well to ND stress, making it a suitable candidate for barely improvement programs. These findings may help to better understand the mechanism of ND tolerance and thus lead to the development of cultivars with improved nitrogen use efficiency (NUE) in barley.

Nitrogen (N) is an essential element for plant growth, and its deficiency influences plants at several physiological and gene expression levels. Barley (Hordeum vulgare) is one of the most important food grains from the Poaceae family and one of the most important staple food crops. However, the seed yield is limited by a number of stresses, the most important of which is the insufficient use of N. Thus, there is a need to develop N-use effective cultivars. In this study, comparative physiological and molecular analyses were performed using leaf and root tissues from 10 locally grown barley cultivars. The expression levels of nitrate transporters, HvNRT2 genes, were analyzed in the leaf and root tissues of N-deficient (ND) treatments of barley cultivars after 7 and 14 days following ND treatment as compared to the normal condition. Based on the correlation between the traits, root length (RL) had a positive and highly significant correlation with fresh leaf weight (FLW) and ascorbate peroxidase (APX) concentration in roots, indicating a direct root and leaf relationship with the plant development under ND. From the physiological aspects, ND enhanced carotenoids, chlorophylls a/b (Chla/b), total chlorophyll (TCH), leaf antioxidant enzymes such as ascorbate peroxidase (APX), peroxidase (POD), and catalase (CAT), and root antioxidant enzymes (APX and POD) in the Sahra cultivar. The expression levels of HvNRT2.1, HvNRT2.2, and HvNRT2.4 genes were up-regulated under ND conditions. For the morphological traits, ND maintained root dry weight among the cultivars, except for Sahra. Among the studied cultivars, Sahra responded well to ND stress, making it a suitable candidate for barely improvement programs. These findings may help to better understand the mechanism of ND tolerance and thus lead to the development of cultivars with improved nitrogen use efficiency (NUE) in barley. [ABSTRACT FROM AUTHOR]

Background and Objectives: Parsley (Tagetes erecta) is an important bedding plant of asteraceae family. Environmental stresses, especially salinity stress in agricultural soils are increasing. Therefore, it seems necessary to find a suitable solution to reduce the effects of soil salinity and the possibility of cultivation in these types of soils. Meanwhile, growth-promoting bacteria are one of the important options as a factor to deal with these stresses. This research was carried out with the aim of the effect of growth stimulating bacteria as biofertilizers in making parsley plant resistant to salt stress. Materials and Methods: In order to investigate the effect of the application of growth-stimulating bacteria on reducing the effects of salinity stress in orange parsley, a research was conducted in the greenhouse of the Faculty of Agriculture of Zanjan University in 2022. This research was conducted as a factorial experiment in the form of a completely randomized design with treatments, three levels of salinity stress (0, 4 and 8 decisiemens) and three levels of Bacillus bacteria (control, Bacillus subtilis, Bacillus velezensis) in three replications, which in total It formed 27 experimental units. Morpho - physiologycal traits include: plant height, flower diameter, number of flowers, plant fresh weight, plant dry weight, root fresh weight, root dry weight, total chlorophyll, antioxidant, ion leakage percentage, peroxidase enzyme, proline, sodium, potassium and The ratio of sodium to potassium was calculated. Results: The results of this research showed that the effect of salinity stress as well as the effect of bacteria on all traits was significant. The interaction effect of salinity in bacteria was significant in some traits such as fresh and dry weight of roots, diameter and number of flowers, leaf ion leakage percentage, total chlorophyll, peroxidase enzyme, proline, sodium and potassium percentage and sodium to potassium ratio. Based on the results of the comparison of averages, due to salinity stress, plant height, fresh and dry weight of shoot and root, diameter and number of flowers, chlorophyll, potassium percentage decreased significantly and in contrast to the characteristics of flower ion leakage percentage, peroxidase enzyme level, Proline, anthocyanin and antioxidants, sodium and the ratio of sodium to potassium increased. Also, the use of bacteria moderated the negative effects of salinity stress and by increasing the amount of proline, anthocyanin, antioxidant and increasing the amount of potassium, it led to the improvement of growth conditions in 8 and 4 deci siemens per meter salinity stress. Among the bacteria that were used, Bacillus subtilis showed a better response than Bacillus velezensis in ornamental parsley and reduced the effect of salt stress. Conclusion: The results of this research showed that salinity induced negative effects on the morphological, physiological and biochemical characteristics of ornamental cabbage. Growth promoting bacteria reduced the negative effects of salinity stress through direct and indirect mechanisms. Among the bacteria that were used, Bacillus subtilis showed a better response than Bacillus velezensis in ornamental parsley and reduced the effect of salt stress. In other words, at high levels of salinity stress, the damage caused by salinity stress can be prevented by using growthpromoting bacteria. [ABSTRACT FROM AUTHOR]

Introduction and Objective: Black rust is one of the important fungal diseases that widely affects the quantity and quality of wheat in many regions of the world. The damages caused by black rust disease can be more than other pathogens in wheat and its importance is such that millions of hectares of healthy fields with high production potential can be destroyed in less time. Destroy it completely in one month. Resistance is one of the genetic characteristics of the host that plant breeders use to produce cultivars. Lines that are recognized as resistant in a survey can be used as a source of resistance in another breeding program. Genetic resistance reduces or eliminates the consumption of chemical poisons, and as a result, it is considered as the most economical and healthiest method of combating plant diseases. Accordingly, in order to statistically investigate some physiological markers related to resistance to black rust disease, 24 bread wheat genotypes including 8 cultivars and 16 promising lines were studied. In this study, two varieties MV-17 (disease-resistant variety) and Morocco (disease-susceptible variety) were selected as controls in this study due to their different behavior in resistance to wheat black rust. Material and Methods: This experiment was carried out in 2019 in the greenhouse of the Research Institute of Plant Breeding and Seed Preparation under the conditions of infection and non-infection with the native race TKTTF of wheat black rust disease and in the form of a randomized complete block design with four replications. Physiological traits including relative leaf water content (RWC), cell membrane stability (MP), electrical conductivity (EC), chlorophyll content (SPAD) and chlorophyll fluorescence were measured and recorded. Results: At the probability level of 1%, a significant difference between genotypes was observed and the interaction effect of disease x genotype was significant for all traits, which indicates the non-homogeneous difference of genotypes for the studied traits in two conditions of infection and non-infection. Also, for all measured traits, there was a significant difference between two different levels of disease infection, which shows the effect of the black rust pathogen on the relative content of leaves, membrane permeability, electrical conductivity, chlorophyll concentration, primary fluorescence, fluorescence It has maximum, variable fluorescence and photochemical efficiency of photosystem II. The results showed that pathogen contamination increases the relative water content, chlorophyll concentration, membrane permeability, initial fluorescence, maximum fluorescence, variable fluorescence, photochemical efficiency of photosystem II and decrease in electrical conductivity. Based on all studied physiological traits of genotypes MV-17, C-98-17, C-98-11, C-98-5, C-98-12, C-98-18, C-98-16, C-98-3 and CD-94-9 were identified as the genotypes that showed more resistance to the disease agent. There was a high correlation between initial fluorescence, maximum fluorescence, variable fluorescence, photochemical efficiency of photosystem II, membrane permeability and electrical conductivity in response to stem rust. Based on Ward's cluster analysis and detection function analysis, the genotypes were divided into four separate groups in the conditions of infection and non-infection with black rust. They were placed in a group. While, in the condition of no disease contamination, 6, 9, 4 and 5 genotypes were clustered in four separate groups, respectively. Conclusion: This study showed the effect of East Azerbaijan stem rust TKTTF race on the physiological traits of winter cultivars and lines of wheat. This race caused changes in the studied physiological traits in both experimental conditions, from this output it can be concluded that the resistant lines are more resistant to the disease than the commercial variety and are recommended as selected lines in breeding programs should be used. It is worth mentioning that according to the results of the grouping of genotypes and also the placement of valuable genotypes in terms of relative water content traits, membrane permeability index, chlorophyll content, initial fluorescence, maximum fluorescence, variable fluorescence, and photochemical efficiency. Photosystem II and electrical conductivity in the first and second groups in the conditions of disease infection and non-infection, it was concluded that the results of cluster analysis had a good relationship with the results of variance analysis and comparing the average of the studied traits. The results showed that the physiological traits measured in response to black rust disease have diversity. Therefore, possible genotypes with resistance to this pathogen can be identified by using the changes of these traits. Also, considering the relationship between the results obtained from the evaluation of physiological and pathological traits, the possibility of using physiological traits as indicators related to resistance to wheat black rust disease was benefited. In other words, the physiological indicators used were able to detect the existence of diversity and response to resistance to black rust disease and they can be used as physiological indicators related to resistance to black rust disease of wheat. Examining different traits in different environmental conditions has shown that the way the genotypes act and respond to the pathogen changes with the change of environmental conditions. For this purpose, these studies should be carried out in several years and in different environments. It is also recommended to carry out the above test using agricultural traits at the stage of the sorghum plant as well as biochemical traits related to the disease. [ABSTRACT FROM AUTHOR]

Introduction: Japanese barberry (Berberis thunbergii) is a perennial and woody shrub that grows in different regions of Iran and the world. The Berberidaceae family has a high potential in food and pharmaceutical industries due to its antioxidant, antimicrobial and anticancer activities. Elicitors are biotic or abiotic stimulators that can induce responses in plants. Abiotic elicitors are used to increase secondary metabolites in plants. Nanoparticles have minimum dimensions between one and 100 nanometers, which have specific physical and chemical properties. Like many nanoparticles, zinc oxide and cerium dioxide nanoparticles are toxic to living organisms. The mechanism of toxicity of nanoparticles is generally contributed to the induction of oxidative stress which lead to the formation of free radicals. Nanoparticles of zinc oxide and cerium dioxide can increase the antioxidant capacity of plants by stimulating oxidative stress. Material and methods: In order to study the changes in the physiological and biochemical characteristics of Japanese barberry under the influence of abiotic elicitors, an experiment was conducted in a completely randomized design with three replications in the greenhouse and laboratory of the Faculty of Agriculture and Natural Resources of Imam Khomeini International University in 2019. Treatments were included zinc oxide elicitors (0.1 g/L) and cerium dioxide nanoparticles (0.0002 g/L) and control (no elicitor). In this research, the amounts of protein, antioxidant enzymes and photosynthetic pigments in tissues of Japanese barberry were measured. Data analysis was done with SAS 9.1.3 statistical software. Comparison of means was done with Duncan's multiple range test and graphs were drawn using Excel software. Results and Discussion: The results of the data analysis of variance showed that the effect of treatment with cerium dioxide and zinc oxide nanoparticle elicitors on the amount of leaf protein, antioxidant activity and also the amount of photosynthetic pigments was significant. Comparison of the means showed that these two elicitors increased the leaf protein content by 26.2% and 12.4%, respectively, compared to the control, but they did not have a significant effect on the root protein content. Cerium dioxide decreased the activity of guaiacol peroxidase enzyme by 77.1% in the root; But in leaves, the activity of this enzyme increased by 134.8% due to treatment with zinc oxide. The highest activity of leaf superoxide dismutase enzyme (25.2% increase compared to control) was related to zinc oxide treatment. The lowest content of catalase enzyme in leaves and roots was obtained with cerium dioxide and zinc oxide. Zinc oxide increased the activity of leaf ascorbate peroxidase enzyme by 111.8%; In the root, the highest and lowest activity levels of this enzyme were obtained in the control and cerium dioxide treatments, respectively. Both elicitors significantly increased the leaf peroxidase enzyme activity compared to the control (128.6% and 157.1%, respectively); However, only the treatment with zinc oxide caused a significant increase of 25.5% in the activity of this enzyme in the root. The highest activity of glutathione reductase enzyme in leaf and root was observed in zinc oxide treatment (23.3% and 12.5% increase compared to control). Nano zinc oxide increased the amount of total chlorophyll and carotenoid in the leaves compared to the control by 93.4 and 67.5%, respectively. Conclusion: It was concluded that zinc oxide nanoparticles elicitor had the greatest effect in increasing the amount of photosynthetic pigments and enzyme activity. By using this elicitor in Japanese barberry culture, the amount of antioxidant enzymes can be increased and the extract can be used as a strong antioxidant in pharmaceutical products. [ABSTRACT FROM AUTHOR]

Drought stress is the primary abiotic factor affecting wheat growth, development, and yield formation. The application of plant growth-promoting rhizobacteria (PGPR) represents an environmentally sustainable approach to mitigate the impacts of drought stress on wheat. This study conducted field experiments using two winter wheat varieties, the drought-sensitive variety Jimai 22 and the drought-resistant variety Chang 6878, aiming to investigate the effects of Streptomyces pactum Act12 inoculation on photosynthetic characteristics, physiological parameters, and yield traits during the jointing, heading, and middle-filling stages under drought stress. The results revealed that drought stresses significantly reduced chlorophyll content, leaf area, biomass, and yield in wheat, while Act12 inoculation significantly increased chlorophyll content, photosynthetic efficiency, antioxidant enzyme activity such as superoxide dismutase (SOD) and peroxidase (POD), osmolyte content (proline and soluble proteins), and decreased malondialdehyde (MDA) content. These combined effects alleviated drought stress, resulting in increased biomass and yield in wheat. Under drought stress, an increase in leaf proline content of 13.53% to 53.23% (Jimai 22) and 17.17% to 43.08% (Chang 6878) was observed upon Act12 inoculation. Moreover, a decrease in MDA content was recorded of 15.86% to 53.61% (Jimai 22) and 13.47% to 26.21% (Chang 6878). Notably, there was a corresponding increase in yield of 11.78% (Jimai 22) and 13.55% (Chang 6878). In addition, grain quality analysis revealed a significant improvement in grain hardness with Act12 inoculation. Therefore, Act12 demonstrates the potential for enhancing the sustainable development of wheat production in arid and semi-arid regions. [ABSTRACT FROM AUTHOR]

Durum wheat (Triticum durum Desf.) is a fundamental staple food for the countries of the Mediterranean basin. Climate change is predicted to cause a trend of increasing drought severity in this region in the near future, necessitating the improvement of durum wheat's resilience to drought stress. Using polyethylene glycol to simulate water scarcity, early vigour parameters in germinating seeds are quickly, easily and affordably assessed. Many screenings, however, only consider the seedling stage; consequently, genotypes identified as promising for cultivation in drought scenarios, may not show such features if drought appears in later phenological phases, as happens in Mediterranean climatic areas, generally prone to terminal drought. The correlation between drought stress resistance during the seedling stage (early vigour) and later stages in the life cycle is elusive due to the lack of scientific efforts. Here we used polyethylene glycol screening to classify fifty‐five tetraploid wheat accessions into three clusters (susceptible, medium resistant and highly resistant to drought), based on morpho‐physiological traits. These accessions included durum wheat cultivars and landraces, as well as ancestors like durum emmer wheat and wild emmer wheat. The results of the screenings were combined with subsequent pot experiments using nine randomly selected accessions, imposing terminal drought, and evaluating their performance. Principal component analysis was performed on data for net photosynthesis, stomatal conductance, transpiration and grain yield. Notably, the genotypes that performed best in the pot experiments were also those that performed well in the screening. Highly resistant candidates had in fact higher physiological and performance parameters than susceptible candidates. In summary, polyethylene glycol screening of germinating seeds resulted to be suitable to predictively evaluate drought resistance in tetraploid wheat accessions under terminal drought conditions, typical of Mediterranean climate zones. The reported data, thus evidence of how this inexpensive and simple method might be efficiently applied for large‐scale phenotyping. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) is the most extensively cultivated cereal crop in the world; however, its growth and development are affected by different types of biotic and abiotic stress conditions. The aim of this study was to assess the physico-chemical diversity in different wheat genotypes under rain-fed conditions. Principle component analysis (PCA) showed that significant variation for different components contributed 77.87% of total variability among all genotypes. In the scree plot, the first two PCs (PC1 = 44.75%, PC2 = 14.28%) had significant differences for numerous agronomic traits. The scatter biplot depicted eight genotypes (Zardana, NR-462, D-97, BARS-2009 (a check), NR-481, Tarnab-73, NR-489 and Pirsabak-91) with high diversity (variation ~90%) for different morphological traits, identifiable as they were located further away from the origin than other genotypes. Factor analysis of loading factors among wheat genotypes across different morpho-physiological traits also showed significant diversity for positive and negative loads. In cluster analysis, genotypes such as BWP-97, BARS-2009, NR-489, NR-448 and Pak. 13 were outliers, indicating significant diversity among all genotypes for different agronomic traits. Biochemical analysis showed maximum values for antioxidant activity, total phenolic content, and total flavonoid content in lines NR-485 (93.76%), NR-489 (3.55 mg gallic acid equivalent (GAE)/g), and the variety Suleman-96 (3.45mg quercetin equivalent (QE)/g), respectively. This study provides new insights for understanding the diversity of different wheat genotypes under rain-fed conditions, and the selected genotypes can be evaluated for further breeding programs. [ABSTRACT FROM AUTHOR]

Introduction: Given the increasing demand for food due to population growth, besides the limited availability of arable land, the role of increasing production through plant breeding is evident. Maize is one of the key agricultural products in the world, a primary food source for humans and animals, and also used for biomass and bio-product production. Referring to the increased vigor of hybrids compared to their parents' heterosis can help to increase crop yields. Maize hybrids produced by crossing two or more pure lines have higher yields than pure maize. Therefore, the present study aimed to estimate heterosis and evaluate the coefficient of phenotypic and genetic variations and heritability in maize hybrids. Materials and methods: The plant materials included the maternal parent (MS02), the paternal parent (TS01), and the SC01 offspring evaluated during the 2023 growing season at the Agricultural and Natural Resources Research and Education Center of Ardabil Province (Moghan) in a randomized complete block design with four replications. Agrophysiological traits included plant height, grain yield, pigment content, stomatal conductance, and chlorophyll fluorescence, antioxidant defense system traits included proline, polyphenols, malondialdehyde, hydrogen peroxide, soluble protein, and antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POX), and catalase (CAT). Analysis of variance (ANOVA) was performed to estimate the coefficients of phenotypic and genetic variations, general heritability, and heterosis based on the mean of parents and the superior parent. Results: The analysis of variance showed significant differences among the genotypes (MS02×TS01; SC01) in terms of the studied traits. The difference between genotypes was significant for all agro-physiological traits and antioxidant defense systems except for chlorophyll a, Fm, Fv and Fv/Fm. According to the results, among the studied traits, chlorophyll fluorescence (Fm) and hydrogen peroxide content had the highest mean values, error variance, genetic variance, and phenotypic variance compared to the other traits. Moreover, the CAT enzyme had the highest error variance, genetic variance, phenotypic variance, genetic diversity coefficient, and phenotypic diversity coefficient among the antioxidant enzymes. These results indicate that heterosis could significantly improve the morphological traits of F1 hybrid maize (SC01). Furthermore, high genotypic variance for most traits shows a high potential for improving these traits through plant breeding. The range of heterosis variations (relative to the mean of parents) among the evaluated traits was between -0.04 and 95.19, indicating the diversity of heterosis levels among the evaluated traits in the SC01 hybrid. Conclusion: Given the observed diversity in the present study, indicating the presence of alleles with dominance effects in agrophysiological traits and traits related to the antioxidant defense system, as well as the desirable diversity and heritability in agrophysiological traits and antioxidant defense systems, there are differences between the maternal and paternal lines of the SC01 hybrid. It seems that using agro-physiological traits and antioxidant defense systems may be useful in determining the best crosses to maximize heterosis in maize. The observed heterosis provides an opportunity to develop new hybrids with better performance and quality. Selecting genotypes with desirable alleles and suitable parents with high genetic diversity is an effective strategy for hybrid maize breeding that may result in increased grain yield and improved photosynthetic efficiency. [ABSTRACT FROM AUTHOR]

Despite its ability to thrive in high-temperature environments, cowpea productivity can be hampered by heat stress, particularly when night air temperatures exceed 17 °C. The crop's germplasm pool potentially possesses significant genetic variability that can be harnessed to breed for heat-tolerant varieties. Progress in improving the crop for heat tolerance has been limited, especially under the hot, short-day environments typical of sub-Saharan Africa. Only a few heat-tolerant varieties have been released, partly due to the limited understanding of heat stress tolerance mechanisms and environmental interaction effects on genotypes, as well as imprecise phenotyping. This review contributes to the literature on cowpea heat stress by highlighting key achievements, challenges, and future directions in breeding heat-tolerant cowpea genotypes and by providing additional information from the recent literature. We opine that the genetic variability for heat tolerance-related traits in cowpea has not been sufficiently exploited in developing varieties adapted to the target production environments. Therefore, attention should be given to assessing the crop's genetic repository by targeting adaptive, morphological, and physiological traits that enhance heat stress tolerance. We propose that breeding programs integrate phenotyping of whole-plant physiological traits and molecular breeding to identify breeder-friendly markers for routine selection. This should be followed by introgression of the heat-tolerant favourable alleles to adapted susceptible varieties using rapid and precise approaches that take advantage of modern genetic and genomic resources such as innovative genetic resources, genomic selection, speed breeding, and genome editing technologies. These tools hold great promise in fast-tracking the development of improved heat-tolerant varieties and incorporating the must-have traits preferred by cowpea farmers and consumers. In view of the likely increase in atmospheric temperature to be occasioned by climate change, there is an urgent need to develop heat-tolerant cowpea varieties to ensure the sustainability of current and future cropping and agri-food systems. [ABSTRACT FROM AUTHOR]

Aims: Copper (Cu) is essential for enzymatic systems, electron transport during photosynthesis, and lignin synthesis, affecting plant metabolism and growth. Cu deficiency is observed in young tree orchards, possibly induced by interaction with other mineral nutrients, although visual symptoms are not easily characterized. This study evaluated the induction of Cu deficiency in citrus, due to high nitrogen (N) fertilization, based on the assessment of biochemical parameters, gas exchange, and anatomy of plant tissues. Methods: Valencia orange trees were submitted to levels of Cu supply via fertigation in addition to foliar spraying (control without Cu or with 2.4 g plant−1 of Cu), and N (medium = 8.6 or high = 25.9 g plant−1 of N) for 210 days. Results: Plants well supplied with Cu exhibited higher electron transport rate, net CO2 assimilation, transpiration, and stomatal conductance, in comparison to the control without Cu. Those grown with high N exhibited greater electron transport rate compared to medium N. Plants without Cu and high N supply exhibited the lowest nitrate reductase activity, whereas plants fertilized with Cu and high N exhibited the greatest increase in the activity of this enzyme, in addition to the highest levels of total free amino acids. Furthermore, plants without Cu and high N exhibited the lowest Cu/Zn-SOD II isoform activity. Loose parenchyma structures of leaves and branches were associated with visual symptoms of Cu deficiency. Conclusion: Plant responses demonstrated how Cu deficiency is induced in citrus trees by excess N, thus highlighting the importance of establishing best nutrient management for sustainable fruit production. [ABSTRACT FROM AUTHOR]

Maize is an economically vital cereal crop. However, water deficiency can severely impact its productivity. Thus, it is necessary to implement an essential approach to increase maize yield while navigating the limitations imposed by scarce water supplies. The present study aimed to investigate whether foliar applications of silicon (Si) and zinc (Zn) could mitigate the adverse effects of water deficiency and improve maize growth and yield. Field experiments were conducted in Egypt during two growing seasons (2021–2022) under three irrigation regimes: full irrigation (ET0), moderate stress (ET1), and severe stress (ET2). The treatments comprised foliar sprays of Si, Zn, Si + Zn, and water control. Phenological, growth, physiological, chemical, and yield-related traits were assessed. Results showed that adequate irrigation (ET0) enhanced most parameters compared to water stress treatments. Under ET0, the combined silicon and zinc treatment resulted in the highest values for plant height, leaf area, chlorophyll content, grains per ear, kernel weight, ear size, and yield compared to other foliar treatments. Under drought stress (ET1, ET2), Si + Zn applications maintained superiority in mitigating yield losses. Proline accumulation was highest under severe stress (ET2) in the absence of foliar sprays, indicating greater drought impacts. Correlation analysis revealed positive associations of grain yield with ear size, leaf area, kernel weight, and biological yield. Cluster analysis separated irrigation regimes and visualized the consistently beneficial effects of Si + Zn across all water levels. Overall, the results demonstrate the synergistic potential of Si and Zn supplementation to sustain maize performance and yields under varying water availability.

At present, the state has introduced the policy of forest Chinese herbal medicine planting planning, strictly prohibiting the planting of Chinese herbal medicine in basic farmland, coupled with the fact that the continuous cropping obstacles of Panax notoginseng have not yet been solved, which makes the area of arable land suitable for planting become less and less. However, the effect of soil moisture regulation on the growth of Panax notoginseng cultivated on sloping arable land has not been reported. Thus, the aim of this study was to investigate the impact of various irrigation levels and slopes on Panax notoginseng agronomic traits, physiological characteristics, disease attributes, biomass, and quality characteristics. During 2018–2020, a field experiment was conducted in the Panax notoginseng growing seasons with three irrigation levels (I1: 70–75% θFC, I2: 75–80% θFC, I3: 80–85% θFC) and three slopes (S1: 2.43°, S2: 6.38°, S3: 16.38°). The results evidenced that the photosynthetic characteristics, root hydraulic conductivity characteristics, biomass and PNS of Panax notoginseng reached the maximum value in the I2S2 treatment, and at the same time, the incidence rate of Panax notoginseng root rot was the lowest. Therefore, based on the results of this study, irrigation volume I2S2 should be regarded as the optimal slope and irrigation management strategies for reducing Panax notoginseng diseases and realizing stable yield and quality improvement of Panax notoginseng. A multi-objective optimization model was established through binary quadratic regression analysis. The findings evidenced that when the irrigation interval was 187–203 mm and the slope interval was 5–10.7°, Panax notoginseng had the lowest incidengce rate, and the root biomass and saponin content reached > 95% of the maximum values at the same time.

Yield potential of maize having distinct genetic diversity in Eastern Himalayan Region (EHR) hill ecologies is often limited by Al toxicity caused due to soil acidity. Stress physiological analysis of local check exposed to 0–300 μM Al under sand culture revealed that 150 μM Al as critical and 200 μM Al as tolerable limit. Increase in Al from 0 to 300 μM reduced total chlorophyll, carotenoids by 74.8 % and 44.7 % respectively and enhanced anthocyanin by 35.3 % whereas LA, SLW and SL have reduced by 81.3%, 21.3 % and 47.8 % respectively. R/S ratio was 51.0 and 13.7 % higher at lower Al levels (50 μM and 100 μM) and photosynthetic, transpiration rate and TDM were 62.5 %, 42.9 % and 78.6 % lower at higher Al (300 μM) as compared to control. TRL, RSA, RDW and RV at higher Al (300 μM) were 92.6 %, 98.7 %, 78.7 and 97.5 % lower over control respectively. Root and shoot Al and PUpE at higher Al (300 μM) was 194.0, 69.2 and 830 % higher whereas PUE decreased to 88.5 % over control. Evaluation of 31 indigenous maize cultivars at 0, 150, and 250 μM Al in sand culture, alongside tolerance scoring and assessment, revealed that Megha-9, Megha-10, and MZM-19 exhibits high Al tolerance, Megha-1, MZM-22, and MZM-42 demonstrated moderate tolerance, whereas Uruapara, Sublgarh, and BRL Para were identified as Al-sensitive. Stress physiological parameters like SDW, TDM, TRL, SL and LA contributed 46.02 % of variability to PC1, whereas A, RV, RSA, anthocyanin and Chlorophyll_b, contributed 13.56 % of variability to PC2. Highest values of CMS, SL, LP, LA, TRL and anthocyanin were recorded in cluster I having sensitive cultivars while highest CMS, SL, LA, LP, TRL and RSA were found in cluster II having moderately tolerant cultivars and highest mean values for TRL, RSA, LP, LA, CMS and SL were recorded in cluster III having highly Al stress tolerant cultivars. The traits viz., A, RV, RSA, anthocyanin and Chlorophyll_b, total chlorophyll and TDM were emanated as physio-morphological for assessing Al toxicity stress tolerance in Maize with high divergence values. Tolerant cultivars showing 63.4 % and 22.4 % higher anthocyanin at 150 μM Al and 250 μM Al than moderately tolerant one in acid soil experiment with increased root Al, shoot Al, root P and shoot P by 42.6 %, 11 %, 95.1 % and 34 % respectively were emerged as promising for novel maize improvement under acid soils of EHR.

Rationale: Increased aridity has led to drought-induced mortality or loss of health for many tree species. Of particular interest is to explore the response of the Mediterranean tree species cork oak (Quercus suber) to this declining phenomenon due to its severity and its large implications for the local economy and the provision of highly relevant ecosystem services. Approach: To assess geographical variations in the response to water stress, we analyzed under controlled conditions the effects of four watering levels and the resistance to a terminal drought on seedlings collected from nine populations covering the complete latitudinal distribution of the species. We explored the response of a number of physiological traits and markers of oxidative stress potentially related with drought-resistance. Findings: We found a highly plastic phenotypic response of most variables to water availability and a large influence of seedlings provenance in the drought-resistance strategies. Although the oxidative stress enzymes ruled out differential water stress throughout the distribution range, we found that seedlings from the southern limit are less vulnerable to drought than other populations. Southern seedlings adapted to xeric conditions displayed a larger sensitivity of stomata to changes in soil humidity and a higher water use efficiency. These physiological local adaptations coupled with larger acorn size in the southern populations, resulted in larger aboveground biomass and higher drought resistance at the southern distribution edge. Conclusions: Our data suggest that this evergreen tree species relies on its physiological plasticity to develop adaptative features that allows it to overcome water shortage and that southern populations hold genetic diversity that could improve the specie´s adaptation in the forecasted drought context with relevant implications for conservation programs.

Various biological traits support the invasive success of different organisms. The osmoregulatory capacity and food preferences of the signal crayfish Pacifastacus leniusculus were experimentally tested to determine if they contribute to its invasive success. The osmotic concentrations of haemolymph were determined after acclimation of the crustaceans to seven salinities from 0 to 20 PSU. Food preferences were tested using Canadian pondweed Elodea canadensis, and rainbow trout Oncorhynchus mykiss. The results showed that the signal crayfish exhibits a hyper-hypoosmotic regulation pattern in the salinity range from 0 to 20 PSU, enabling them to inhabit both freshwater and brackish environments. Furthermore, the study found signal crayfish to have non-specific food preferences, although fish muscle tissue is more beneficial as a source of energy. Both features, osmoregulatory ability and food preferences, can increase the invasive success of this species as it expands into new areas. The ability to survive in higher salinities compared to the coastal waters of the Baltic Sea along the Polish coastline should be considered in targeted management strategies to control the spread of this invasive species.

The leading role of Italy in the cultivation of durum wheat stimulated intense breeding activities in the country from the beginning of the 20th century, much earlier than in any other country involved in durum wheat production. Older, genetically more heterogeneous landraces were replaced with new, highly productive, superior quality varieties, and this led to an inevitable reduction in the overall genetic diversity among new cultivars, which makes the genetic variability preserved in old cultivars particularly valuable and important. The aim of this paper was to assist future breeding programs by providing a detailed description of the history of durum wheat breeding in Italy and of the changes in yield, quality, and related traits that subsequently occurred, starting from the most diffuse landraces present between 1900 and 1920 up until the present day. The parallel evolution of breeding techniques, breeding goals, and agricultural systems in this period is also described, and some future breeding goals suggested. In the current context of climate change and of rapidly mutating pathogen populations, preserving the yield level through the continuous introduction of new cultivars by exploiting the reservoir of largely unused genetic variation stored in old cultivars and landraces could be as important as increasing grain yield and quality. [ABSTRACT FROM AUTHOR]

Currently, more than half of the global nations cultivating wheat crops are facing severe consequences of climate change and its associated heat stress in terms of quantitative and qualitative yield losses. Plants exposed to heat stress need a balanced and adequate amount of mineral nutrients to counter its ill effects. Therefore, the present study was designed to investigate the potential effects of heat stress applied during the vegetative growth period (Zadoks growth scale: ZGS 5-60) on physiological and phenotypic traits of wheat (Triticum aestivum) crop subjected to variable rates of nitrogen (N). In this experiment, wheat plants of cv. 'Punjab-2011' were exposed to two levels of temperature i.e. heat stress (HS) and control or non-heat stress (NHS), and three N rates (N50 = 50 kg ha-1, N100= 100 kg ha-1 and N150 = 150 kg ha-1). The experiment was executed under controlled conditions in a completely randomized design (CRD) with six replications. One set of eighteen pots containing wheat seedlings was placed in a compartment of the greenhouse under heat-stressed conditions, while another set was placed in another compartment under non-heated conditions. The greenhouse compartments were equipped with a heating and cooling system to maintain desired ecological conditions. Pots in heated chamber were kept for 60 days from emergence (ZGS = 5-60), and then shifted to non-heated chamber till harvesting. The temperature in heat stress treatment was almost 2 ± 0.47 °C higher than in non-heated treatment. The results indicated that HS significantly reduced the photosynthetic rate by 42.52%, leaf photosynthetic efficiency by 56.82%, chlorophyll scores by 20.11%, relative water contents (RWC) by 12.81%, tillers by 48.21%, grain weight by 21.47% and grain yield by 68.20% relative to NHS conditions. These reductions were more prominent in plants subjected to a limited N dose rate (50 kg N ha-1). Furthermore, the results also revealed higher transpiration rate, stomatal conductance, and membrane ruptures under HS with N50 treatment. However, N150 treatment compensated for the detrimental effects of HS on wheat plants by improving the photosynthetic rate and efficiencies, higher RWC, more stability of membrane and pigments, more tillers, and higher grain weight, and grain yield of wheat. Additionally, grain yield was negatively correlated with transpiration rate, stomatal conductance, internal CO2 concentration, and membrane leakage. In conclusion, a high dose rate of N under high temperatures during vegetative growth could alleviate the magnitude of penalties to grain yield and enhance the potential of wheat crops to withstand heat-induced detrimental effects. [ABSTRACT FROM AUTHOR]

Drought stress is a significant constraint that affects the yield of almost all major crops. Its impact is expected to worsen due to global climate change and human population expansion. Potato (Solanum tuberosum L.) is the third most important food crop worldwide, but it is highly susceptible to drought stress. In order to understand the effects of drought stress on yield and identify traits for selecting drought-tolerant potato genotypes, we evaluated the response of a range of agronomic and physiological traits in 15 potato genotypes under well-watered (WW) and water deficit (WD) conditions. The harvest index (HI) was found to have a high plot-based heritability (0.98), indicating that it can be used for the indirect selection of drought-tolerant genotypes. In contrast, SPAD was sensitive to detecting early drought stress in potatoes. Drought-tolerant genotypes, including CIP392797.22 (UNICA), CIP397077.16, CIP398190.89, CIP398208.219, and CIP398208.620, were able to allocate limited water towards tuber production rather than biomass. These genotypes showed high tuber production under WW conditions and increased photosynthetic activity and water use efficiency under WD conditions. [ABSTRACT FROM AUTHOR]

Soybean is a very important crop due to its multiple uses, but hydric stress can substantially reduce soybean production. The response of soybean plants to drought and the compensation effect of growth after rehydration has been very little studied. In this context, this paper presents results regarding the response of some soybean genotypes to water stress and soil rehydration. Our goal being to identify genotypes that have a compensation mechanism in response to drought to support breeding for drought resistance and higher yields. Eight soybean genotypes were studied under greenhouse conditions. Water stress inhibited the growth of soybean plants. After rehydration, soybean plant height and leaf surface showed a rapid growth/recovery and produced good compensation compared to the root system where the compensation phenomenon was less. Water stress reduced the chlorophyll content and upon rehydration, different levels of compensation were observed in each studied genotype, there was even one genotype that showed an overcompensation. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) field experiments commenced during crop season 2022 at the Experimental Farm, Al-Mahnawiya, Extension Training Center, Babylon, Iraq. The study examined the impacts of water stress tolerance on four maize cultivars' AP2 gene expression, physiology, and yield. The experiment used a randomized complete block design (RCBD) with a split-plot arrangement and three replications. Four irrigation treatments applied on the main plots comprised 1) full irrigation (control), 2) withholding irrigation during elongation (Gs-V7), 3) non-irrigation during grain-filling (Gs-R2), and 4) suppressing irrigation during both elongation and grain-filling (Gs-V7+R2). The subplots included four maize cultivars: Furat, Dijlah, ZP, and Konsens. The results showed that withholding water during maize plants' elongation stage (GS-V7) significantly reduced leaf water and chlorophyll content. However, withholding irrigation increased peroxidase and catalase enzyme concentrations significantly. Suppressing irrigation at the elongation stage (GS-V7) and the elongation and grainfilling stages (GS-V7+R2) resulted in a considerable drop in cycle threshold (CT) values, with average CT values of 31.68 and 31.69 cycles, respectively. The AP2 gene expression and CT values indicated a negative correlation. The study found that the AP2 gene increases maize's water stress tolerance, and the gene expression in maize cultivar "Furat" confirms this. Maize cultivar Furat achieved recommendations for cultivation in desert regions because of its superior ability to survive and adapt. [ABSTRACT FROM AUTHOR]

Gac is a carotenoid-rich, healthful tropical fruit; however, its productivity is limited by soil salinity, a growing environmental stress. This study aimed to evaluate the effects of salinity stress on key physiological traits and metabolites in 30-day-old gac seedling leaves, treated with 0, 25-, 50-, 100-, and 150-mM sodium chloride (NaCl) for four weeks to identify potential alarm, acclimatory, and exhaustion responses. Electrolyte leakage increased with increasing NaCl concentrations (p < 0.05) indicating loss of membrane permeability and conditions that lead to reactive oxygen species production. At 25 and 50 mM NaCl, superoxide dismutase (SOD) activity, starch content, and total soluble sugar increased. Chlorophyll a, and total chlorophyll increased at 25 mM NaCl but decreased at higher NaCl concentrations indicating salinity-induced thylakoid membrane degradation and chlorophyllase activity. Catalase (CAT) activity decreased (p < 0.05) at all NaCl treatments, while ascorbate peroxidase (APX) and guaiacol peroxidase (GPX) activities were highest at 150 mM NaCl. GC-MS-metabolite profiling showed that 150 mM NaCl induced the largest changes in metabolites and was thus distinct. Thirteen pathways and 7.73% of metabolites differed between the control and all the salt-treated seedlings. Salinity decreased TCA cycle intermediates, and there were less sugars for growth but more for osmoprotection, with the latter augmented by increased amino acids. Although 150 mM NaCl level decreased SOD activity, the APX and GPX enzymes were still active, and some carbohydrates and metabolites also accumulated to promote salinity resistance via multiple mechanisms.