The present study aimed to validate the identified marker trait associations (MTAs) for stay-green (SG) and stem reserve mobilisation (SRM) using 12 wheat genotypes. Out of 12 genotypes, equal number of genotypes (6 each) had higher and lower SG and SRM traits. These genotypes were selected from our previous genome-wide association study for SG and SRM traits. Validation of mapped MTAs have been accomplished by using physiological and gene expression approach. Gene expression analysis of the identified genes in the MTAs region were carried out in these selected contrasting lines in a pot experiment site at Division of Plant Physiology, Indian Agricultural Research Institute (IARI), New Delhi, India. For SG traits, canopy temperature (CT), soil plant analysis development (SPAD) value, leaf senescence rate (LSR) was recorded, whereas for SRM, stem reserve mobilisation efficiency (SRE) was measured. The experiment was carried out in completely randomized design (CRD), under control and combined heat and drought stress (HD) condition. Plants in the control condition (timely sown) were irrigated at their critical phenological stages throughout the cropping period, while under combined stress (50 days late sown), irrigation was withheld at the flowering stage to impose drought stress. Candidate genes found in the overlapping region and within the region of 100 Kb intervals flanking either side of the associated markers were identified through BioMart tool in Ensemble Plants platform. Real-time gene expression analysis was performed on SG-associated genes in the flag leaf and SRM- associated genes in the peduncle. Phenotypic assessment showed that there was significant genotypic variation for the SG and SRM traits and yield. Low SG and SRM performing genotypes showed around 27% and 37% faster leaf senescence rate (LSR) than high SG and SRM performing genotypes under control and HD conditions, respectively, which confirming to our mapped MTAs for SG and SRM traits. HD3366 showed highest stem reserve mobilisation efficiency (SRE) of around 85% under combined stress, while lowest of around 27% was recorded in MP1369 under control condition. Thousand grain weight (TGW) showed negative association with LSR, while positive correlation with SRE. However, highest relative gene expression of cytokinin dehydrogenase 11-like (TaCKX11) was recorded in low performing SG and SRM genotypes, while lowest expression was recorded in high performing SG and SRM genotypes. Expression analysis of candidate genes like protein phosphatase 2C (TaPP2C), TaCKX11, protein detoxification 40-like (TaPD), F-box protein (TaFBP) and pentatricopeptide repeat (TaPPR) were associated with leaf senescence (SG- linked). Genes linked with SRE, such as serine/threonine-protein kinase 2 (TaSK2) and wall-associated receptor kinase 4- like (TaWAK) exhibited the highest expression levels during 12 days after anthesis, suggesting their involvement in enhanced carbon reserve mobilization to the grain under stress conditions. Our study confirmed the association of mapped markers and its linked traits, which can be used in further marker-assisted selection (MAS) using efficient breeding tools.

The present study investigated of general combing ability of the parents and specific combining ability of hybrids and gene action for biochemical traits of Ornamental kale (Brassica oleracea var. acephala) using three cytoplasmic male sterile (CMS) lines and ten doubled haploid (DH) testers in a Line × Tester mating design to elucidate the genetic control of key biochemical traits related to pigment concentration and antioxidant capacity. Thirty F₁ hybrids, along with parents, were evaluated for chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, phenol, lycopene, ascorbic acid, and antioxidant activity (CUPRAC, FRAP) and ascorbic acid. Analysis of variance revealed highly significant differences among genotypes, indicating substantial genetic variability and strong potential for improvement. Significant line × tester interactions for most traits indicated the predominance of non-additive gene action. Mean performance identified CMS-3 × KTDH-55, CMS-1 × KTDH-56, and CMS-2 × KTDH-13 as superior hybrids for multiple biochemical attributes. GCA effects indicated CMS-1, KTDH-56, and KTDH-13 as promising general combiners for pigment and antioxidant traits, demonstrating the involvement of additive gene action. In contrast, several hybrids such as CMS-1 × KTDH-56, CMS-3 × KTDH-55, CMS-2 × KTDH-13, and CMS-1 × KTDH-29 exhibited high and positive SCA effects, confirming the influence of non-additive gene effects. Overall, the study highlights the effectiveness of CMS- and DH-based heterosis breeding for enhancing pigment concentration, biochemical quality, and antioxidant potential in ornamental kale. These findings provide valuable parental combinations and genetic insights for developing high-quality ornamental kale hybrids with improved aesthetic and nutritional properties.

To meet the ever-increasing demand for food, there is a huge concern about the selection of superior genotypes with enhanced resilience to abiotic stress. However, choice/selection of suitable genotype/line is complex due to significant interaction of genotypes with environmental factors. Aiming few traits for selection may simplify the statistical analysis, however selection of genotypes using multiple traits is quite difficult. Furthermore, use of any single index may bias the selection of genotypes. Here, we proposed one method for selection of superior genotypes using combined approach of four selection indexes such as, multi-trait genotype-ideotype distance index (MGIDI), factor analysis and genotype-ideotype distance (FAI-BLUP), Smith-Hazel index (SHI) and multi-trait stability index (MTSI) under multi-environment stress conditions by using R programming. From our study, twenty random recombinant inbred wheat lines among the 220 lines developed by crossing HD3086 and HI1500 has been taken for analysis. The selection intensity (SI) was 15% for all the indexes. The lines were tested for stay-green and stem reserve mobilisation traits under control, drought, heat and combined stress conditions. Result found that RIL-10 was common to these four indexes by using venn diagram and was considered to be superior among the lines, which can perform better under multi-environment stress conditions. Thus, we recommend that combined approach of several indexes can be used a robust method for selection of ideal genotypes in wheat and other crop as well.

Water-soluble carbohydrates (WSCs) serve as a potential buffer for grain filling in wheat, when current leaf photosynthesis is inhibited by abiotic stress. The potential of genotype to store WSCs for its remobilisation is determined by its stem-specific weight i.e. stem density. To examine the extent to which mobilisation of carbon reserve occurs under multi-environment conditions and the genomic regions associated with stem density in wheat, a field experiment was conducted at Indian Agricultural Research Institute (IARI), New Delhi, India with 220 wheat RILs developed by crossing HD3086 and HI1500 under control, drought, heat and combined stress (heat and drought) conditions. Genotyping of population (21 days seedling) was done with 35 K Wheat Breeder Array followed by QTL mapping with inclusive composite interval mapping (ICIM) software. Selection of superior lines were carried out by using combined approach of multi-trait genotype-ideotype distance index (MGIDI), factor analysis and genotype-ideotype distance (FAI-BLUP) and Smith-Hazel index (SH). In our study, total 9 quantitative traits loci (QTLs) were mapped, which were linked to stem density (peduncle, penultimate and lower internode) with LOD score > 3.5, of which 7 were mapped as major QTLs. In-silico gene expression analysis revealed various important genes like sugar transport protein MST4, PPR containing protein, trehalose phosphate synthase, NRT1/PTR FAMILY 8.3-like etc., which are probably involved in maintaining stem density in wheat. Moreover, four lines (HDHI-12, HDHI-87, HDHI-142 and HDHI-194) were identified as superior lines, which can be used as potential donors to elite wheat cultivars. Our study shed light on genetic basis of regulation of stem density in wheat, which accelerates the possible marker-assisted and genomic selection for higher stem density and stem reserve mobilisation.

The experiment was conducted during winter (rabi) season of 2020–21 and 2021–22 at ICAR-Indian Agricultural Research Institute, New Delhi to assess the individual and combined effects of drought and heat stresses on bread wheat (Triticum aestivum L.), focusing on yield, yield-contributing parameters, and grain nutritional quality in four contrasting wheat genotypes (C306, HD2967, Raj3765 and WL711). The experiment was laid out in completely randomized design (CRD) with 15 replications of each genotype. The results revealed that combined drought and heat stress had a more severe impact on yield-related traits compared to individual stresses. Yield losses under drought stress ranged from 17.7–32.24%, while heat stress alone caused reductions of 29.98–46.55%. However, the combined stress led to the highest yield loss (42.13–61.06%), emphasizing the additive detrimental effects of both stresses. Similarly, 1000-kernel weight (TKW) declined significantly under combined stress conditions, with reductions ranging from 33.22–52.23%, due to impaired starch synthesis and reduced enzymatic activity. Genotype Raj3765 exhibited the highest tolerance, followed by C306, HD2967, and WL711, as indicated by the Stress Susceptibility Index (SSI) and Yield Stability Ratio (YSR). Additionally, nutritional quality assessments showed a decline in zinc (Zn) and iron (Fe) concentrations under drought and combined stresses, with Raj3765 exhibiting the least reduction and WL711 the highest. Despite reductions in starch content, protein content increased under heat stress, suggesting differential regulation of nitrogen metabolism. These findings highlight the necessity of breeding wheat varieties with enhanced resilience to multiple stress factors to sustain grain yield and nutritional quality under climate change scenarios.

Garden pea (Pisum sativum L., 2n = 2x = 14) is commonly grown cool season leguminous vegetable in India. The knowledge on crop genetic diversity is essential for its exploitation in breeding programmes. The present study was carried out to assess morphological and molecular diversity among 82 garden pea genotypes. The genotypes were characterized for 9 qualitative and 11 quantitative morphological parameters during two cropping seasons of 2020–2021 and 2021–2022. The genetic analysis revealed wide variation among all the lines under study for all the agro-morphological traits. The cluster analysis and heat map based on quantitative morphological traits classified most of the exotic genotypes together. Similarly, molecular diversity estimated using 38 polymorphic SSR markers revealed that the major allele frequency ranged from 0.23 to 0.95 and allele number ranged from 2 to 10 with an average of 5.00 alleles per marker. Among 38 polymorphic SSR markers, 32 markers had PIC value more than 0.3 with mean PIC of 0.46. The NJ dendrogram classified the 82 genotypes into 2 major clusters. The population structure analysis revealed that there were four distinct populations in studied garden pea genotypes and it was observed that similar to morphological clustering, population structure analysis also grouped most of the exotic genotypes together in population IV. Analysis of molecular variance (AMOVA) revealed that there was significant molecular difference among the studied genotypes. Thus, a combined approach of morphological and molecular diversity analysis will be helpful in widening the genetic base of garden pea genotypes for future breeding programmes.

The common bean is an essential legume crop that faces significant productivity threats from high temperature stress (HTS). It negatively impacts physio-biochemical processes, floral organ development, and fertilization, and degrades seed and nutritional quality, leading to yield losses. To alleviate the impact of HTS on common bean genotypes that are tolerant to water deficit stress (WDS), foliar applications (0 and 300 µM) of melatonin (MT), a low-molecular-weight organic compound that acts as both a plant hormone and an antioxidant, was applied at pre and post flowering stage of the crop. Two experiments were conducted to study the efficacy of MT foliar application on common bean genotypes under HTS (I & II) conditions during the late Rabi (post-rainy) season of 2023-24. Foliar application of MT reduced the canopy temperature by 29.1% under HTS-I (29-32 °C) and 7.9% under HTS-II (32-35 °C) and increased the pollen viability by 25.8% and 45.9% under HTS-I and II, respectively. In addition, MT significantly enhanced seed yield, with increases of 11.2% and 34.4% under HTS-I and HTS-II, respectively. MT also increased the micronutrient content of the seeds under HTS. Overall, these results provide a comprehensive understanding of the protective and tolerance effects of MT against HTS, ensuring yield stability in HTS-prone areas.

Stay-green (SG) and stem reserve mobilization (SRM) are two significant mutually exclusive traits, which contributes to grain-filling during drought and heat stress in wheat. The current research was conducted in a genome-wide association study (GWAS) panel consisting of 278 wheat genotypes of advanced breeding lines to find the markers linked with SG and SRM traits and also to screen the superior genotypes. SG and SRM traits, viz. soil plant analysis development (SPAD) value, canopy temperature (CT), normalized difference vegetation index (NDVI), leaf senescence rate (LSR) and stem reserve mobilization efficiency (SRE) were recorded. The trial was conducted in α-lattice design, under control and combined heat and drought stress (HD). Analysis of variance and descriptive statistics showed a significant difference across the evaluated traits. The highest mean of SRE (31.7

Wheat yield is hampered by heat stress during the reproductive stage, and climate change is expected to worsen this effect. Wheat semi-dwarf alleles reduced height, and improved productive tillers ensured food security. However, it is unclear how semi-dwarfism, and exogenous application of growth regulators interact to alleviate heat stress. Therefore, the present study attempted to understand the effect of gibberellic acid 3 (GA3) and paclobutrazol (PBZ) on semi-dwarf (GA-insensitive) and tall (GA-sensitive) wheat genotypes under stressed environments. The exogenous application of GA3 and PBZ both influenced endogenous GA3 levels in leaves; however, PBZ had a more pronounced effect on GA-sensitive genotypes compared to GA-insensitive genotypes under heat stress. It was found that the reduction in photosynthesis rate under stress could be effectively mitigated by PBZ application in GA-insensitive genotypes. Our study also concludes that GA3 plays a minor role in conferring heat tolerance, as neither GA-sensitivity nor exogenous GA3 application significantly affected antioxidant enzymes activities or reactive oxygen species (ROS). In contrast, PBZ application enhanced heat stress tolerance by increasing antioxidant enzyme levels and membrane stability, while reducing ROS and lipid peroxidation. Additionally, PBZ's inhibition of kaurene oxidase suggests the activation of alternative pathways for the biosynthesis of defense compounds, such as diterpenoid phytoalexins, which further promote stress tolerance. Although GA3 had a negligible effect on stress tolerance, it significantly increased 1000-grain weight in GA-sensitive genotypes compared to GA-insensitive ones. This suggests that the greater yield reduction in GA-insensitive genotypes under stress was primarily due to a decrease in grain and tiller numbers rather than test weight. (c) 2024 SAAB. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Introduction:Abiotic stress significantly reduces the wheat yield by hindering several physiological processes in plant. Stay-green (SG) and stem reserve mobilization (SRM) are the two key physiological traits, which can contribute significantly to grain filling during stress period. Validation of genomic regions linked to SG and SRM is needed for its subsequent use in marker-assisted selection in breeding program. Methods:Using a physiological and gene expression approach, quantitative trait loci (QTLs) for stay-green (SG) and stem reserve mobilization (SRM) were validated in a pot experiment study using contrasting recombinant inbred lines including its parental lines (HD3086/HI1500) in wheat. The experiment was laid down in a completely randomized design under normal (control, drought) and late sown (heat and combined stress) conditions during the 2022-2023 rabi season. Drought stress was imposed by withholding irrigation at the anthesis stage, whereas heat stress was imposed by 1-month late sowing compared to the normal sowing condition. Combined stress was imposed by 1-month late sowing along with restricted irrigation at the flowering stage. Superior lines (HDHI113 and HDHI87) had both SG and SRM traits, whereas inferior lines (HDHI185 and HDHI80) had contrasting traits, i.e., lower SG and SRM traits. HD3086 and HI1500 had SG and SRM traits respectively. Potential candidate genes were identified based on the flanking markers of the mapped QTLs using the BioMart tool in the Ensembl Plants database to validate the identified QTLs. Real-time gene expression was conducted with SG-linked genes in the flag leaf and SRM-linked genes in the peduncle. Results and Discussion:In this study, HDHI113 and HDHI87 showed higher expression of SG-related genes in the flag leaf under stress conditions. Furthermore, HDHI113 and HDHI87 maintained higher chlorophyll a content of 7.08 and 6.62 mg/gDW, respectively, and higher net photosynthetic rates (PN) of 17.18 and 16.48 µmol CO2/m2/s, respectively, under the combined stress condition. However, these lines showed higher expression of SRM-linked genes in the peduncle under drought stress, indicating that drought stress aggravates SRM in wheat. HDHI113 and HDHI87 recorded higher 1,000-grain weights and spike weight differences under combined stress, further validating the identified QTLs being linked to SG and SRM traits. Henceforth, the identified QTLs can be transferred to developed wheat varieties through efficient breeding strategies for yield improvement in harsh climate conditions.

Heat stress is a detrimental abiotic stress that limits the development of many plant species and is linked to a variety of cellular and physiological problems. Heat stress affects membrane fluidity, which leads to negative effects on cell permeability and ion transport. Research reveals that heat stress causes severe damage to cells and leads to rapid accumulation of reactive oxygen species (ROS), which could cause programmed cell death. This current study aimed to validate the role of Triticum aestivum Salt Stress Root Protein (TaSSRP) in plants’ tolerance to heat stress by modulating its expression in tobacco plants. The Relative Water Content (RWC), total chlorophyll content, and Membrane Stability Index (MSI) of the seven distinct transgenic lines (T0 − 2, T0 − 3, T0 − 6, T0 − 8, T0 − 9, T0 − 11, and T0 − 13), increased in response to heat stress. Despite the fact that the same tendency was detected in wild-type (WT) plants, changes in physio-biochemical parameters were greater in transgenic lines than in WT plants. The expression analysis revealed that the transgene TaSSRP expressed from 1.00 to 1.809 folds in different lines in the transgenic tobacco plants. The gene TaSSRP offered resistance to heat stress in Nicotiana tabacum, according to the results of the study. These findings could help to improve our knowledge and understanding of the mechanism underlying thermotolerance in wheat, and the novel identified gene TaSSRP could be used in generating wheat varieties with enhanced tolerance to heat stress.

Recent years witnessed an increasing consumer interest for the consumption of fruits preserved with nonchemical, eco and health-friendly approaches. This led to continuous work on deriving plant based natural treatments such as essential oils (EOs) for managing postharvest fruit loss. However, selection of EO which bear preservation potential along with the quality retention (sensory and shelf-life attributes) is now a prime concern for the postharvest researchers. Present study uncovers the preservation ability of EOs such as thyme oil (0.1 % v/v), clove oil (0.06 % v/v), neem oil (2 % v/v) and citronella oil (0.01 % v/v) on keeping quality, fruit decay and shelf life of mangoes cv. 'Amrapali'. The fruit were subjected to EOs coating dip treatment for 3 min, followed by storage at ambient condition. Observations on postharvest attributes (physical, physiological, biochemicals, decay and sensory) were recorded at 3 days interval up to storage period completion (12th day). The results showed that all EOs positively influenced the studied preservation characteristics. Interestingly, thyme oil (0.1 %) application exhibited the excellent level of overall fruit quality and preservation potential. This treatment exhibited highest overall fruit quality (7.71) and sensory score (6.47) while controlling the 'quality deterioration attributes' such as physiological loss (6.91 %), fruit respiration-ethylene activity and fruit softening enzymes activities to the least level. Moreover 3 days extension of storage period along with >90% decay control was achieved over control fruit. It was concluded that thyme oil (0.1 %) exhibited the best preservation potential on keeping mangoes fresh. The outcome of this study bears practical utility for fruit preservation industry, organic farming, and fruit traders. (c) 2024 SAAB. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Mango is a commercial fruit crop of India that suffers huge postharvest losses every year. The application of biocontrol agents (BCAs) bears a vast potential for managing the same, which is yet to be exploited to its fullest extent. Hence, studies were conducted for BCAs application of Debaryomyces hansenii, Bacillus subtilis and Pseudomonas fluorescens strains on mango fruit under in-vitro, in-vivo conditions to know the efficacy of these BCAs on the postharvest pathogen, shelf life and quality retention of mango fruit. The ‘poisoned food technique’ was attempted for in-vitro studies. For the in-vivo studies, fruit of the commercial cultivar ‘Amrapali’ were un-inoculated and pre-inoculated with major postharvest pathogens (anthracnose: Colletotrichum gloeosporioides and stem-end rot: Botryodiplodia theobromae) were treated with BCA, followed by ambient storage at (24 ± 4 °C, 75 ± 5 % RH). From the results, it has been observed that under in vitro studies, BCA Debaryomyces hansenii (Strain: KP006) and Bacillus subtilis (Strain: BJ0011) at the treatment level 108 CFU mL−1 while, the Pseudomonas fluorescens at 109 CFU mL−1 (Strain: BE0001) were significantly effective for pathogen inhibition. However, under the in vivo studies, the BCA Debaryomyces hansenii (Strain: KP006) at 108 CFU mL−1 treatment level was found to significantly reduce the pathogen's decay incidence while positively influencing the shelf life and biochemical (quality) attributes. This treatment increased the storage life of mango fruit by more than three days over control fruit. Therefore, BCA Debaryomyces hansenii (Strain: KP006) at 108 CFU mL−1 can be used to control the postharvest pathological loss of mango fruit without affecting its internal quality.

Introduction Rice is a primary food source almost for more than 50% of the total world's population. Glycemic index (GI) is high in most of the rice varieties, limiting their consumption by diabetic and obese people. As a result, developing new rice varieties with low GI necessitates a thorough understanding of starch biogenesis gene expression and its interrelationship.Methods A total 200 rice genotypes were analyzed for total starch content (TSC), amylopectin content (APC), and amylose content (AC). The clustering of these rice genotypes was done based on their AC. Further, these genotypes were categorized into three groups up to 10% amylose-low, 10-26% amylose-medium, and more than 26% amylose-high. Among them, six genotypes 1 from low AC (NJ-72), 2 from medium AC (UPRI-2003-18, PRR-126), and 3 from high AC (RNRM-7, Urvashi and Ananga) were selected. The genotypes selected from the medium and high AC groups were having 2% amylose variation among themselves respectively and they were further used to study the level of RS, protein content (PC), fatty acid (FA) profiles, and granule morphology along with low group sample.Results Resistant starch (RS) content ranged from 0.33-2.75%, and fatty acid profiling revealed high levels of palmitic, linoleic, and oleic acids. The degree of crystallinity and APC% were found to be positively correlated. Ananga, the genotype with the highest RS, displayed compact starch granules. Further, NJ-72 showing low RS and Ananga with high RS were selected for investigation of enzymatic activities of starch biosynthesis, metabolites accumulation, and expressions of 20 starch biogenesis genes in developing endosperm. Starch branching enzymes (SBE) and starch synthase (SS) activities peaked at 13 days after anthesis (DAA), while starch debranching enzymes (DBE) were most active at 18 DAA. In Ananga, TSC, AC, APC, and RS levels progressively increased from 3 to 23 DAA. Ananga showed 1.25-fold upregulation of granule-bound starch synthase I (GBSSI) at 18DAA. Higher expressions of SSI and SBEIIb were observed in NJ-72 at 13DAA. PUL2 was predominantly expressed followed by ISA1. GBSSI was positively correlated with both AC and RS while SS, SBE, and DBE were positively related to APC.Conclusion This research could lead to the development of rice varieties with improved nutritional qualities, such as higher RS content, which is beneficial for human health due to its role in lowering glycemic response and promoting gut health. Additionally, the study provides insights into how the modulation of key genes and enzymes can affect starch composition, offering strategies to breed rice varieties tailored for specific dietary needs or industrial applications.

Melatonin is a signalling molecule in plants which act as a growth regulator and stress buffering agent but little is known about its defensive role in heat stress tolerance in rice. In this study we analysed the acclimation response of two contrasting heat responsive rice genotypes NERICA-L-44 (NL-44, heat stress tolerant) and Pusa Basmati 1121 (PB-1121, heat stress susceptible) to exogenous melatonin treatment under heat stress. Heat stress induces melatonin biosynthesis in both the genotypes and maximum increase was observed in NL-44. Application of exogenous melatonin further increases melatonin biosynthesis and endogenous content significantly in PB-1121. To understand melatonin’s role in alleviating effects of heat stress, some of the heat stress associated traits such as membrane stability index, hydrogen peroxide content, malondialdehyde content, total antioxidant capacity and enzymatic antioxidants like superoxide dismutase, catalase, ascorbate peroxidase and peroxidase were analysed. We observed that melatonin significantly enhanced membrane stability by reducing hydrogen peroxide mediated membrane damage. Higher activity of antioxidative enzymes and increased total antioxidant capacity helped to maintain reactive oxygen species homeostasis by scavenging mechanism. Exogenous melatonin increased pollen viability, spikelet fertility and grain yield under heat stress treatment. The findings of this study indicates that heat stress induced increase in melatonin biosynthesis may be involved in heat stress tolerance in rice. Exogenous melatonin treatment can further improve heat stress tolerance in susceptible rice genotype (PB-1121) by activating antioxidative mechanism.

Introduction: Abiotic stresses significantly reduce crop yield by adversely affecting many physio-biochemical processes. Several physiological traits have been targeted and improved for yield enhancement in limiting environmental conditions. Amongst them, staygreen and stem reserve mobilisation are two important mutually exclusive traits contributing to grain filling under drought and heat stress in wheat. Henceforth, the present study was carried out to identify the QTLs governing these traits and to identify the superiors’ lines through multi-trait genotype-ideotype distance index (MGIDI)Methods: A mapping population consisting of 166 recombinant inbred lines (RILs) developed from a cross between HD3086 and HI1500 was utilized in this study. The experiment was laid down in alpha lattice design in four environmental conditions viz. Control, drought, heat and combined stress (heat and drought). Genotyping of parents and RILs was carried out with 35 K Axiom® array (Wheat breeder array).Results and Discussion: Medium to high heritability with a moderate to high correlation between traits was observed. Principal component analysis (PCA) was performed to derive latent variables in the original set of traits and the relationship of these traits with latent variables.From this study, 14 QTLs were identified, out of which 11, 2, and 1 for soil plant analysis development (SPAD) value, leaf senescence rate (LSR), and stem reserve mobilisation efficiency (SRE) respectively. Quantitative trait loci (QTLs) for SPAD value harbored various genes like Dirigent protein 6-like, Protein FATTY ACID EXPORT 3, glucan synthase-3 and Ubiquitin carboxyl-terminal hydrolase, whereas QTLs for LSR were found to contain various genes like aspartyl protease family protein, potassium transporter, inositol-tetrakisphosphate 1-kinase, and DNA polymerase epsilon subunit D-like. Furthermore, the chromosomal region for SRE was found to be associated with serine-threonine protein kinase. Serine-threonine protein kinases are involved in many signaling networks such as ABA mediated ROS signaling and acclimation to environmental stimuli. After the validation of QTLs in multilocation trials, these QTLs can be used for marker-assisted selection (MAS) in breeding programs.

Wheat productivity is severely affected by drought and heat stress conditions worldwide. Currently, stem reserve mobilization (SRM) is receiving increased attention as a trait that can sustain wheat yields under adverse environments. However, the significance of SRM in sustaining wheat yields under drought and heat stress conditions remains uncertain in the tropical climate of Indo-Gangetic Plain region. Therefore, this study aimed to investigate genotypic variations in SRM in wheat and their influence on yield sustainability under drought and heat stress environments. The experiment was designed in an alpha-lattice layout, accommodating 43 genotypes under four simulated environments [timely sown and well irrigated (non-stress); timely sown and water-deficit/drought stress; late-sown and well-irrigated crop facing terminally high temperature; and late-sown and water-deficit stress (both water-deficit and heat stress)]. The water-deficit stress significantly increased SRM (16%–68%, p < 0.01) compared to the non-stress environment, while the heat stress conditions reduced SRM (12%–18%). Both SRM and stem reserve mobilization efficiency exhibited positive correlations with grain weight (grain weight spike−1) under all three different stress treatments (p < 0.05). Strong positive correlations between stem weight (at 12 days after anthesis) and grain weight were observed across the environments (p < 0.001); however, a significant positive correlation between stem weight and SRM was observed only with stress treatments. Results revealed that the SRM trait could effectively alleviate the impacts of water-deficit stress on yields. However, the SRM-mediated yield protection was uncertain under heat stress and combined water-deficit and heat stress treatments, possibly due to sink inefficiencies caused by high temperature during the reproductive period. Defoliated plants exhibited higher SRM than non-defoliated plants, with the highest increment observed in the non-stress treatment compared to all the stress treatments. Results revealed that wider genetic variability exists for the SRM trait, which could be used to improve wheat yield under drought stress conditions.

High temperature causes several morphological, physiological, and biochemical changes in crop plants, and garden pea is highly sensitive to a higher temperature than other legume crops. This study assessed garden pea genotypes' physiological and biochemical responses during a reproductive stage in regular and heat stress season at the Division of Vegetable Science, Indian Agricultural Research Institute, New Delhi (India). Forty-five garden pea genotypes, including 15 tolerant, 15 moderately tolerant, and 15 susceptible genotypes, were analyzed for three physiological, six biochemical, and 11 quantitative morphological traits under regular and heat stress seasons. Our results showed a considerable decrease in leaf water content, greenness index, and membrane stability index in heat stress season and a substantial increase in malondialdehyde, hydrogen peroxide, and antioxidant enzymes in heat stress season compared to the regular season. The 15 heat-tolerant genotypes showed a significant increase in antioxidant enzymes compared to the 15 heat-susceptible genotypes, which impart thermotolerance by scavenging reactive oxygen species generated in high-temperature stress conditions. Further, correlation and biplot analysis of morpho-physiological and biochemical traits indicated that physiological and biochemical traits were important in determining yield and related traits under heat stress conditions in garden pea genotypes. Thus, estimating critical physiological and biochemical traits could facilitate in differentiating thermotolerant genotypes from susceptible genotypes in garden peas and aid in heat-tolerant breeding programs of similar cool-season legume crops.

An experiment was conducted during winter (rabi) seasons of 2020–21 and 2021–22 at the research farm of ICAR-Indian Agricultural Research Institute, New Delhi to assess the impacts of heat and drought stresses, both individually and combined, on wheat (Triticum aestivum L.) plants during the reproductive stage. Four wheat genotypes (C306, HD2967, Raj3765 and WL711) were subjected to heat stress (H), drought stress (D) and combined heat, and drought stress (HD) conditions at the anthesis stage. The research investigated various physiological, biochemical and grain yield parameters, as well as the relative expression of genes involved in the proline and abscisic acid (ABA) metabolic pathways. Among the tested genotypes, Raj3765 exhibited decreased ABA levels and increased proline accumulation during the anthesis stage under both individual and combined stress conditions. Notably, Raj3765 also displayed highergrain yield compared to the other 3 genotypes under all stress conditions, indicating that elevated proline levels and reduced ABA levels likely contributed to its resilience. Furthermore, the study revealed that the combination of heat and drought stresses had a more severe detrimental effect on wheat plants compared to individual stress treatments. These findings underscore the significance of comprehensively studying combined stress conditions, as they can result in substantial yield losses in wheat crop development and productivity.