The unpredicted rise in temperature is severely affecting plant growth and productivity. To avoid future food shortages, crop yield protection is probably the greatest challenge being faced by modern agriculture. In the present study, we assessed the response of 19 wheat cultivars to high temperature and subsequent developmental stages during three successive field trials following a Randomized Block Design (RBD) with three replications. In one of the growing seasons, wheat leaf samples at different developmental stages (booting, anthesis and milking) were analyzed for membrane stability, relative leaf water content and antioxidative enzyme activity. After harvesting, the crop was analyzed for yield-related parameters. The rise in temperature dramatically affected membrane stability at different stages of development. Distinct yield parameters recorded indicated variation in the yield potential of wheat cultivars. Principal Component Analysis showed that the PBW and KRL cultivars were positively correlated to yield parameters and negatively correlated to height and biomass. Membrane damage was more prominent during the milking (grain filling) stage and positively correlated with antioxidant enzyme activity. These outcomes suggest that wheat cultivars have the varied potential for thermotolerance, and it depends upon water status which could be further useful to develop heat tolerant varieties in breeding programs.

Chickpea is an important food legume grown all over the world. However, it experiences various environmental stresses throughout the life cycle resulting in productivity loss. The Lipoxygenase (LOX) pathway followed by Jasmonic acid (JA) biosynthesis is a key metabolic pathway activated in responses to various environmental cues. But there is lack of such studies in chickpea about LOX-JA biosynthetic pathway and its role in heat stress. In the present study, a comprehensive integration of these pathways was analysed in Desi and Kabuli chickpea. Initially a genome-wide analysis was performed to identify and characterize the genes involved in the LOX-JA biosynthetic pathway. A total of 128 novel genes were identified related to LOX-JA biosynthetic pathway. These include 37 LOX, 59 HPL, 12 AOS, 4 AOC and 16 OPR genes in Desi and Kabuli. The identified gene sequences were used for in-silico characterization and analysis. The cis regulatory elements were also identified to know about their functional diversity. The subcellular localization in the cytoplasm and other cell organelles suggests their involvement in development, stress response, and signal transduction. There is structural diversity among the members of the LOX and JA biosynthetic gene families. The phylogenetic and synteny analysis indicated common evolutionary history and similar functional roles. Later, gene expression and biochemical analysis revealed that with upregulation of JA-Biosynthetic pathway heat stress tolerance also improved in chickpea. Overall, these findings suggested that MeJA alleviates the high temperature stress by upregulating LOX-JA pathway and maintaining membrane integrity, water status and solutes at seedling stage. The MeJA alleviates the high temperature stress by upregulating LOX-JA pathway genes and maintaining membrane integrity, water status and key solutes in chickpea seedlings.

The effects of irrigation scheduling and biofertiliser application on growth, yield and water-use dynamics of late-sown wheat (Triticum aestivum L.) were evaluated through a field experiment conducted during the rabi season of 2019–20 at Chandra Shekhar Azad University of Agriculture and Technology, Kanpur, Uttar Pradesh. The experiment was laid out in a split-plot design with 3 irrigation schedules in main plots: crown root initiation (CRI) stage only (IR1), CRI + late jointing (IR2) and CRI + tillering + milking (IR3) and 4 seed-inoculated biofertiliser treatments in sub-plots: Azotobacter (F1), phosphate-solubilising bacteria (PSB) (F2), Azotobacter + PSB (F3) and liquid phosphate (F4). Irrigation at (IR3 significantly enhanced growth parameters, yield attributes and grain yield compared to limited irrigation schedules. Among biofertilisers, combined inoculation with (F3 resulted in superior growth, yield, water-use efficiency and water productivity over individual applications. Therefore, scheduling irrigation at critical growth stages combined with dual biofertiliser inoculation optimises yield and water use efficiency of late-sown wheat under the agro-climatic conditions of central Uttar Pradesh.

Chickpea is highly sensitive to cold stress during its reproductive stages, leading to significant reductions in potential pod formation due to decreased reproductive success. This study aimed to investigate the specific responses of anthers and ovules to cold stress, explore the role of oxidative stress and antioxidant mechanisms, and understand the relationship between oxidative stress and reproductive function to enhance our understanding of chickpea responses to cold stress. Chickpea seeds of contrasting genotypes—cold-tolerant (ICC 17258, ICC 16349) and cold-sensitive (ICC 15567, GPF 2)—were sown outdoors in early November under optimal conditions (25.5/15.4°C mean day/night temperatures). At 50 days after sowing, plants were subjected to 13/7°C cold stress (12 h light/dark in walk-in growth chambers. Cold stress significantly increased membrane damage and reduced cellular viability in anthers and ovules, particularly in cold-sensitive (CS) genotypes. Oxidative damage was more pronounced in anthers, particularly at anthesis (stage 2), as indicated by elevated malondialdehyde and hydrogen peroxide levels. Cold-tolerant (CT) genotypes exhibited increased antioxidant activity under stress, especially at pre-anthesis (stage 1), followed by declines at later stage, although responses varied by genotype. Anthers exhibited higher overall antioxidants activity than ovules, while ovules demonstrated notably high catalase activity. Among the antioxidants studied, ascorbate peroxidase and glutathione reductase were most prominent in the CT genotype, along with higher levels of ascorbate (AsA) and glutathione (GSH), highlighting the critical role of the AsA–GSH cycle in conferring cold tolerance to chickpea. Exogenous supplementation with 1 mM ascorbate (AsA) and glutathione (GSH) significantly stimulated pollen germination in cold-stressed plants under in vitro conditions, with a greater effect observed in CS genotypes. Furthermore, antioxidant activity strongly correlated with key reproductive traits such as pollen germination and ovule viability. This study revealed that the anthers and ovules exhibited distinct responses to cold stress, with significant genotypic differences across key reproductive stages. These insights provide a deeper understanding of cold tolerance mechanisms in chickpea and provide vital clues for breeding strategies to enhance resilience and reproductive success under cold stress.

Chickpea, a vital legume crop, is highly susceptible to cold stress, especially during its reproductive phase, resulting in significant flower and pod abortions and reduced seed yield. Our previous study demonstrated that cold acclimation is effective in enhancing cold tolerance but benefits only cold-tolerant (CT) genotypes, while cold-sensitive (CS) genotypes remain unaffected. In this extended study aimed at probing the detailed mechanisms of this differential response, we further examined the expression profiles of enzymes involved in the synthesis and breakdown of osmolytes (pyrroline-5-carboxylate synthase, proline dehydrogenase (PDH), betaine aldehyde dehydrogenase) and sugars (sucrose synthase, acid invertase, trehalose-6-phosphate synthase, trehalose-6-phosphate phosphatase, and trehalase activity), along with the expression of various antioxidants (superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase) in both CT and CS genotypes. Seeds of two contrasting chickpea genotypes, cold-tolerant ICC 17258 and cold-sensitive ICC 15567, were planted in pots during the first week of November in an outdoor field environment. After 40 days, the plants were transferred to walk-in growth chambers for cold acclimation at specific temperatures. Initially, the plants were exposed the plants to 25/18℃ (pre-acclimation stage; PAS) for 2 days, followed by a 21-day cold acclimation period with progressively decreasing temperatures over seven days for each cold acclimation stage (CAS): CAS1 (21/13℃), CAS2 (18/10℃), and CAS3 (15/8℃). Subsequently, the plants were subjected to cold stress at 13/7℃ for 15 days and then exposed to 30/23℃ (12 h day/night) until maturity. Our findings demonstrated that the expression of various enzymes involved in the synthesis of osmolytes and sugars in leaves, anthers, and ovules was significantly upregulated during the cold acclimation process in the CT chickpea genotypes but not in the CS genotypes. This enhanced metabolic activity, coupled with elevated levels of enzymatic antioxidants during the acclimation process, contributed to improved leaf water status, photosynthetic efficiency, and ultimately, superior reproductive performance (pollen germination, pollen viability, stigma receptivity, and ovule viability) under cold stress conditions compared to CS genotypes. The enhanced cold tolerance observed in the CT genotypes is likely attributable to their genetic predisposition and efficient stress defense mechanisms facilitated by the upregulated expression of cold-responsive enzymes.

Chickpeas are particularly sensitive to cold stress during the reproductive phase, which can significantly impair pod set and yield. This study examined the role of sodium nitroprusside (SNP), a nitric oxide (NO) donor, in mitigating cold-induced reproductive damage in cold-tolerant (CT) and cold-sensitive (CS) chickpea genotypes. After 100 days of outdoor growth, plants were subjected to cold stress (15/8°C day/night; 12 h photoperiod) for 21 days in walk-in growth chambers during the reproductive stage of development. Control plants were maintained at 25/15°C day/night temperature. SNP treatment (1 mM) was applied exogenously each time, first two days prior to stress onset and then at seven-day intervals (three applications total). Cold stress significantly lowered endogenous NO levels in leaves, anthers, and ovules, particularly in CS genotypes, thereby leading to reduced pollen viability and germination. SNP treatment restored NO and improved reproductive performance, with stronger responses in the CS than the CT genotype. For instance, pollen germination increased by 57.9% in CS versus 17.6% in CT, and pollen viability increased by 28.0% and 13.1%, respectively. Enhanced anther function resulted in a 157.2% increase in pod set and 62.0% higher seed yield in CS. SNP also improved physiological traits, including a 43.9% increase in cellular viability, 18.6% in stomatal conductance, and 41.9% in chlorophyll content in CS genotypes. Cryoprotectants (proline, trehalose, and sucrose) accumulated in anthers, reinforcing cold resilience, while oxidative stress was simultaneously alleviated through reduced malondialdehyde, hydrogen peroxide, and electrolyte leakage, together with the upregulation of both enzymatic (superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APx), and glutathione reductase (GR)) and non-enzymatic (ascorbic acid (ASC) and reduced glutathione (GSH)) components. Notably, CS genotypes showed more pronounced improvements from SNP application than CT genotypes, particularly in terms of reproductive success and yield-related traits. These findings highlight the potential of NO donors, such as SNP, to enhance cold tolerance in chickpeas, with promising implications for safeguarding productivity under low-temperature stress, especially in sensitive cultivars.

Growing chickpea (Cicer arietinum L.) faces significant challenges due to rising temperatures and drought stress, particularly during the reproductive and seed-filling phases. This study investigated the single and joint impacts of drought and heat stress on seed development, focusing on the responses of drought-tolerant (DT) and drought-sensitive (DS) chickpea genotypes. Initially raised in an outdoor environment (mean day and night temperature of 27 and 16±1 °C, respectively, light intensity of 1230–1440 µmol m−2 s−1, relative humidity of 70/43 %) until seed filling (around 110–113 days after sowing) commenced. The plants were subsequently exposed to single or combined heat and drought stress under controlled conditions until maturity. Control pots were maintained at day and night temperature of 25 and 15 °C, respectively with 500 µmol m−2 s−1 light, 60–65 % RH, and regular irrigation, and drought-stressed pots were kept at 50 % field capacity under the same conditions of light and humidity. Heat stress in pots was gradually increased to 32(day)/20 °C (night) under regular irrigation, while combined stress pots experienced both drought (50 % field capacity) and heat stress conditions 32(day)/20 °C (night) under the same light and humidity conditions with irrigation. All stress treatments adversely affected cell membranes, photosynthesis, and water regulation, with more pronounced effects under combined stress. While heat stress increased stomatal conductance, drought and combined stress significantly reduced it. Seed filling rate and duration decreased under all stress conditions, especially combined stress. The stresses in combination severely reduced seed weight and pod numbers compared to individual stresses. Enzyme activities involved in starch and sucrose synthesis and hydrolysis substantially decreased under the combined stress. Seed composition elements (starch, storage proteins, sugars, fat, crude fiber, and ash) exhibited significant reductions across all stress treatments, particularly for the combined stress. Thus, under combined stresses, starch, proteins, and soulube sugars were markedly decreased to 13–20 %, 6.4–12.4 %, and 3–5 % in seeds, compared to 37–39 %, 21–24 %, and 6 % in control seeds. The DT genotype outperformed the DS genotype for all traits under individual and combined stress conditions. Principal component analysis revealed a complex interplay among various physiological responses (membrane damage, chlorophyll, chlorophyll fluorescence, relative leaf water content, and stomatal conductance), seed yield, and seed composition under the combined stress. This study highlighted that combined heat and drought stress severely impacted chickpea yield and nutritional traits, such as seed starch and protein content, compared to individual stresses underscoring the need to develop cultivars tolerant to this stress combination.

Multi-parent advanced generation inter-cross (MAGIC) populations have been developed and utilized in crop improvement programs in several economically important crops. In the current study, soybean (Glycine max L.) MAGIC population was evaluated at four locations to identify stable and high-yielding MAGIC RILs (recombinant inbred lines) and to understand the genotype and environmental interaction for grain yield and attributing traits. For different traits under study, pooled analysis of variance indicated the significant genotype x environmental interactions at p < 0.01. RILs such as G236, G455, G159, G493, and G488 found ideal for grain yield across the four environments. Through multi-trait genotype-ideotype distance index ideotype-MAGIC RILs have been identified for each location. Significant positive correlation of grain yield with pods per plant, 100-seed weight, plant height, number of nodes per plant, and branches per plant has been identified. Under field conditions, screening of F-2:3 generation of MAGIC population revealed that only 59 progenies exhibited adult plant resistance for charcoal rot disease (caused by Macrophomina phaseolina). Although under controlled conditions parental genotypes EC 572136 and EC 572109 found to be partially resistant with least mean necrosis length, MAGIC RILs (F-2:8) showed variable reaction. Thus, the study established diverse genetic resources useful for both mapping and varietal development program.

In wheat (Triticum aestivum L.), terminal heat stress obstructs reproductive functioning eventually leading to yield loss. Drought priming during the vegetative stage can trigger a quicker and effective defense response against impending high temperature stress and improve crop production. In the present study, two contrasting wheat cultivars (PBW670 and C306) were subjected to moderate drought stress of 50-55% field capacity for eight days during the jointing stage to generate drought priming (DP) response. Fifteen days after anthesis heat stress (36 °C) was imposed for three days and physiological response of primed, and non-primed plants was assessed by analyzing membrane damage, water status and antioxidative enzymes. Heat shock transcription factors (14 TaHSFs), calmodulin (TaCaM5), antioxidative genes (TaSOD, TaPOX), polyamine biosynthesis genes and glutathione biosynthesis genes were analyzed. GC-MS based untargeted metabolite profiling was carried out to underpin the associated metabolic changes. Yield related parameters were recorded at maturity to finally assess the priming response. Heat stress response was visible from day one of exposure in terms of membrane damage and elevated antioxidative enzymes activity. DP reduced the impact of heat stress by lowering the membrane damage (ELI, MDA & LOX) and enhancing antioxidative enzyme activity except APX in both the cultivars. Drought priming upregulated the expression of HSFs, calmodulin, antioxidative genes, polyamines, and the glutathione biosynthesis genes. Drought priming altered key amino acids, carbohydrate, and fatty acid metabolism in PBW670 but also promoted thermotolerance in C306. Overall, DP provided a multifaceted approach against heat stress and positive association with yield.

Chickpea (Cicer arietinum L.) suffers from chilling stress at the reproductive stage (<15 °C) which leads to significant yield loss. This study presents a comprehensive plant response to drought priming and its effect on chilling tolerance during the reproductive stage in two chickpea cultivars PBG1 and PBG5. Lipidome profiling (Fatty acid methyl esters analysis), metabolome profiling (GC-MS based untargeted analysis), fatty acid desaturases and antioxidative gene expression (qRT-PCR) were analyzed to monitor physiological and biochemical events after priming during flowering, podding and seed filling stages. Drought priming alleviated membrane damage and chlorophyll degradation by increasing membrane unsaturated fatty acids (18:3) along with up-regulation of various fatty acid desaturases (CaFADs) genes and antioxidative machinery during flowering and improved seed yield in PBG5. PCA, HCA, and KEGG pathway analysis of 87 identified metabolites showed that metabolites were regulated differently in both cultivars under non-primed and primed conditions. The plant response was more apparent at flowering and podding stages which coincided with chilling temperature (<15 °C). Drought priming stimulated many important genes, especially FADs, antioxidative proteins and accumulation of key metabolites (proline and TCA intermediates) required for defense especially in PBG5. This explains that plant's response to drought priming not only depends on developmental stage, and temperature regime (<15 °C) but also on the genotypic-specificity.

Drought and high temperature stress may occur concomitantly or individually in succession causing cellular dysfunctions. Abscisic acid (ABA) is a key stress regulator, and its responsive genes are controlled by ABRE (Abscisic acid Responsive Element)-binding factors (ABFs)and G-Box Regulatory factors (GRFs). Here, we identify ABFs, GRFs and targeting miRNAs in desi and kabuli chickpea. To validate their role after drought priming and subsequent high temperature stress, two contrasting chickpea varieties (PBG1 and PBG5) were primed and exposed to 32 °C, 35 °C and 38 °C for 12, 6 and 2 h respectively and analyzed for Physio-biochemical, expression of ABFs, GRFs and MiRNAs, and GC-MS based metabolite analysis. To ascertain the ABF-GRF protein-protein interactions, docking studies were carried out between the ABF3 and GRF14. Genome-wide analysis identified total 9 & 11 ABFs, and 11 GRFsin desi and kabuli respectively. Their gene structure, and motif composition were conserved in all subfamilies and only 10 and 12 genes have undergone duplication in both desi and kabuli chickpea respectively. These genes were differentially expressed in-silico. MiR172 and miR396 were identified to target ABFs and GRFs respectively. Protein-protein interaction (ABF3 and GRF14) might be successful only when the ABF3 was phosphorylated. Drought priming downregulated miR172 and miR396 and eventually upregulated targeting ABFs, and GRFs. Metabolite profiling (GC-MS) revealed the accumulation of 87 metabolites in Primed (P) and Non-Primed (NP) Chickpea plants. Tolerant cultivar (PBG5) responded better in all respects however both severity of stress and exposure are important factors and can produce broadly similar cellular response.

Optimum temperature is crucial for plant's survival. During high temperature stress, heat shock proteins (Hsps) are expressed many folds essentially controlled by explicit heat shock factors (Hsfs).We have narrowed key HSPs, related HSFs and miRNAs regulated after priming with drought stress and consequent heat stress in chickpea. Firstly, we identified Hsf and Hsp gene families in desi and kabuli chickpea using Genome-wide analysis. Thereafter, selected Hsfs, Hsps and related miRNAs were analyzed using qRT-PCR in contrasting chickpea varieties (PBG1 and PBG5) after drought priming and exposing at 32 °C 24 hrs, 35 °C 12 hrs, and 38 °C 6 hrs. An interaction network between Hsfs and Hsps was generated. 18 & 17 Hsfs and 42 & 34 Hsps were identified in the desi and kabuli, respectively. The gene structure and motif composition of the genes were found to be conserved in all subfamilies. A total of 32 heat shock genes were found to have undergone duplication. Most of the CaHsf and CaHsp genes were differentially expressed on exposure to a combination of drought priming and heat stress in both in-silico and qPCR analysis. Targeted miRNAs expression was coordinated with the respective genes. miR156, miR166, miR319, miR171, and miR5213 were identified to be targets of sHsps, Hsfs, and Hsps. The protein-protein interaction revealed that CaHsp18.2 and CaHsp70 might be controlled by CaHsfsA1. Drought priming strongly correlated with less membrane damage and better leaf water content. Higher harvest index and root shoot ratio significantly indicated effectiveness of priming and essential role of Hsf and Hsp and related miRNAs in heat stress tolerance.

Priming alleviates membrane damage, chlorophyll degradation along with cryoprotectants accumulation during chilling stress that leads to improved reproductive functioning and increased seed yield. Chilling temperatures below 15 °C have severe implications on the reproductive growth and development of chickpea. The abnormal reproductive development and subsequent reproductive failure lead to substantial yield loss. We exposed five chickpea cultivars (PBG1, GPF2, PDG3, PDG4, and PBG5) to drought stress (Priming) during the vegetative stage and analyzed for chilling tolerance during the reproductive stage. These varieties were raised in the fields in two sets: one set of plants were subjected to drought stress at the vegetative stage for 30 days (priming) and the second set of plants were irrigated regularly (non-primed). The leaf samples were harvested at the flowering, podding, and seed filling stage and analyzed for membrane damage, water status, chlorophyll content, cellular respiration, and certain cryoprotective solutes. The reproductive development was analyzed by accessing pollen viability, in vivo and in vitro germination, pollen load, and in vivo pollen tube growth. Principal component analysis (PCA) revealed that priming improved membrane damage, chlorophyll b degradation, and accumulation of cryoprotectants in GPF2, PDG3, and PBG5 at the flowering stage (< 15 °C). Pearson's correlation analysis showed a negative correlation with the accumulation of proline and carbohydrates with flower, pod, and seed abortion. Only, PBG5 responded best to priming while PBG1 was worst. In PBG5, priming resulted in reduced membrane damage and lipid peroxidation, improved water content, reduced chlorophyll degradation, and enhanced cryoprotective solutes accumulation, which led to increased reproductive functioning and finally improved seed yield and harvest index. Lastly, the priming response is variable and cultivar-specific but overall improve plant tolerance.

Arsenic is a hazardous metalloid that causes detrimental effects on plant growth and metabolism. Plants accumulate arsenic in edible parts that consequently enter the food chain leading to many health problems. Metal tolerant plant growth-promoting bacteria (PGPB) ameliorate heavy metal toxicity. In this study, the effect of arsenic (As5+) and the role of PGPB Pseudomonas citronellolis (PC) in mitigating As5+ toxicity and associated metabolic alterations in chickpea were assessed. Five chickpea varieties (PBG1, GPF2, PDG3, PDG4 and PBG5) were evaluated for arsenic accumulation, translocation, and its interference with metabolic and defense processes. As5+ (40 mg kg-1) interfered with plant metabolism and enhanced the antioxidative and carbohydrate metabolizing enzyme's activity but PC treatment maintained the activity at par with control. PC also facilitated the accumulation of As5+ in the root system and restricted its translocation to the shoot. Further, to map the metabolic changes, Gas chromatography Mass Spectroscopy (GC-MS) based metabolite profiling and gene expression analysis (qRT-PCR) were performed in the best and worst-performing chickpea varieties (PBG1 and PBG5). 48 metabolites of various metabolic pathways (amino acid, carbohydrate, and fatty acid) were altered in As5+ and PC treatment. Gene expressions showed correlation with biochemical analysis of the antioxidative enzymes and carbohydrate metabolizing enzymes while PC treatment improved chlorophyll biosynthesis enzyme CaDALA expression in As5+ treated plants. Therefore, PC mitigates As5+ toxicity by restricting it in the roots thereby maintaining the cellular homeostasis under As5+ stress in chickpeas.

Drought and high temperature stress affect chickpea growth and productivity. Often these stresses occur simultaneously in the field and lead to a wide range of molecular and metabolic adaptations. Two chickpea varieties; GPF2 (heat sensitive) and PDG4 variety (heat tolerant) were exposed to 35 °C for 24 h individually and along with drought stress. Five heat responsive signalling genes and 11 structural genes were analyzed using qPCR along with untargeted metabolites analysis using GC MS. Expression of antioxidant genes (CaSOD and CaGPX, CaAPX and CaCAT), transcription factors (CaHSFB2, CaHSFB2A, CaHSFB2B, CaHSP17.5 and CaHSP22.7) and signalling genes (CaCAM, CaGAD, and CaMAPK) were upregulated in GPF2 as compared to PDG4 variety. Principal component analysis (PCA), partial least-square discriminant analysis (PLS-DA), and heat map analysis were applied to the metabolomics data to identify the differential response of metabolites in two chickpea varieties. GC-MS analysis identified 107 and 83 metabolites in PDG4 and GPF2 varieties respectively. PDG4 variety accumulated more sugars, amino acids, sugar alcohols, TCA cycle intermediates which provided heat resistance. Additionally, the differential metabolic pathways involved in heat tolerance were alanine, aspartate, and glutamate metabolism, pantothenate CoA biosynthesis, fructose and mannose metabolism and pentose phosphate pathway in PDG4 variety. There was less accumulation of metabolites in the primed plants of both varieties as compared to the non-primed plants indicating less damage due to heat stress. The present study gives an overview of the molecular changes occurring in response to heat stress in sensitive and tolerant chickpea.

The rising temperatures are seriously impacting the food crops, including urdbean; hence efforts are needed to identify the sources of heat tolerance in such crops to ensure global food security. In the present study, urdbean genotypes were evaluated for heat tolerance under natural outdoor for two consecutive years (2018, 2019) and subsequently in the controlled environment of the growth chamber to identify high temperature tolerant lines. The genotypes were assessed involving few physiological traits (membrane damage, chlorophyll, photosynthetic efficiency, stomatal conductance, lipid peroxidation), reproductive traits (pollen germination % and pollen viability %) and yield related traits (total number of pods plant-1, total seeds plant-1, single seed weight and seed yield plant-1). Based upon these tested traits, PantU31, Mash114, UTTARA and IPU18-04 genotypes were identified as promising genotypes for both years under heat stress condition. Further confirming heat tolerance, all these four tolerant and four sensitive genotypes were tested under controlled environment under growth chamber condition. All these four genotypes PantU31, Mash114, UTTARA and IPU18-04 showed high chlorophyll content, photosynthetic efficiency, stomatal conductance, leaf area, pods plant-1, total seeds plant-1 and low reduction in pollen germination % and pollen viability under stress heat stress condition. Moreover, yield and yield related traits viz., pods plant-1, seeds plant-1, single seed weight and seed yield plant-1 showed very strong positive correlation with pollen germination and pollen viability except electrolyte leakage and malondialdehyde content. Thus, these genotypes could be potentially used as donors for transferring heat tolerance trait to the elite yet heat-sensitive urdbean cultivars.

Aims The aim of the study is to analyse the effect of microbial consortia for wheat biofortification, growth, yield and soil fertility as part of a 2-year field study and compare it with the use of chemical fertilizers. Methods and Results A field trial (second year) was conducted with various combinations of plant growth-promoting bacteria (PGPB) and arbuscular mycorrhizal fungi (AMF) treatments, ranging from a single inoculant to multiple combinations. The microbial consortia used were Bacillus sp. and AMF based on first-year field trial results. The consortia based on native (CP4) and non-native (AHP3) PGPB (Bacillus sp.) and AMF performed better in terms of nutrients content in wheat grain tissue and yield-related traits compared with chemical fertilizer treated and untreated control. Dual treatment of PGPB (CP4+AHP3) combined with AMF resulted in a significant increase in antioxidants. The spatial colonization of AMF in roots indicated that both the isolates CP4 and AHP3 were able to enhance the AMF colonization in root tissue. Furthermore, soil enzymes' activities were higher with the PGPB and AMF combination giving the best results. A positive correlation was recorded between plant growth, grain yield and soil physicochemical parameters. Conclusions Our findings confirm that the combined treatment of CP4 and AHP3 and AMF functions as an effective microbial consortium with excellent application prospects for wheat biofortification, grain yield and soil fertility compared with chemical fertilizers. Significance and Impact of Study The extensive application of chemical fertilizers on low-yielding field sites is a severe concern for cereal crops, especially wheat in the Asian continent. This study serves as a primer for implementing site-specific sustainable agricultural-management practices using a green technology leading to significant gains in agriculture.

In northern India, chickpea experiences abrupt heat and drought stress during the late developmental stage and entails significant production loss. In the present study, the effect of heat stress and combined stress (heat and drought) was assessed in five varieties of chickpea along with the underlying mechanism of cross-tolerance by priming. Healthy seedlings (24 days old) were primed with mild drought stress and exposed to three different temperatures, i.e., 38 °C, 35 °C, and 32 °C for 12, 24, and 36 h respectively, and also in combination with drought. The damage and tolerance were evaluated based on biochemical and physiological indicators. Results indicate that significant response was observed at 35 °C as compared to 32 and 38 °C in terms of decrease in leaf water content, increased electrolyte leakage and lipid peroxidation, decreased chlorophyll content, increased accumulation of proline and total sugars, and increased antioxidative activity of superoxide dismutase, catalase, guaiacol peroxidase, ascorbate peroxidase, and glutathione reductase. The consequence of combined stress was more distinct than the individual heat stress and cannot be extrapolated from the synergistic effect of the two stresses. In addition, priming induced cross-tolerance at 35 °C by improving the membrane damage, photorespiration, photosynthetic pigment, osmolyte accumulation, and some antioxidative enzymes. On the basis of all the above parameters, PDG4 was identified as the best performing variety and tolerant to heat stress while GPF2 was the worst performing and sensitive to heat stress. It can be inferred that both severity and duration of stress are important and priming can be considered as an important tool to induce cross-tolerance in crop plants.