Morpho-physiological Attributes Research Articles

Genetic Variability for Root and Shoot Morpho-physiological Traits Contributing to Seedling Drought Stress Tolerance in Parental Lines of Pearl Millet

Drought stress severely affects plant growth and development leading to substantial reduction in yield and biomass accumulation. Forty one Pearl millet parental lines were subjected to seedling drought stress and morpho–physiological attributes along with individual drought stress response indices were recorded. Significant genetic variability existed for all the traits and genotype ICMX 1410698-SB-11-1-1-2(B) ranked first based on combined drought stress response index. Principal component analysis indicated that first two PCs explained 86.4% of variation under drought conditions. GCV ranged from 13.84 to 23.47% under drought indicating genetic basis for variability. D2 statistics grouped the genotypes into seven clusters. The maximum inter-cluster distance was reported between the clusters III and VII while clusters III & I ranked second under drought stress. These are potential drought tolerant parental lines for hybrid breeding. Root/Shoot ratio has been the major contributor for genetic divergence under both control and drought stress.

Study of Physiological Growth Indices and Yield of Chickpea (Cicer arietinum L.) to Soil and Foliar Application Through Integrated Nutrient Management Practices

An investigation was conducted in Rabi season of 2023-24 at the instructional farm of Karunya Institute of Technology and Sciences, Coimbatore, to evaluate the performance of physiological indices on chickpeas under soil and foliar application. The experiment was established on a Factorial Randomized Block Design (FRBD). The treatments were soil application of NPK 100 percent (A1), NPK 100 percent + FYM 10 t ha-1 (A2), NPK 100 percent + Vermicompost 5 t ha-1 (A3), NPK 75 percent + FYM 10 t ha-1 (A4) and NPK 75 percent + Vermicompost 5 t ha-1 (A5) combined with foliar applications, viz., Nano-DAP (B1) and Nano-Urea (B2). The results of the study revealed that morpho-physiological attributes of chickpeas were statistically increased by the application of soil (NPK 75 percent + Vermicompost 5 t ha-1) combined with foliar (Nano-urea) nutrient management practices resulting in maximum grain yield of 15.64 q ha-1 and stover yield of 30.49 q ha-1. The results of this study underscore the importance of integrated nutrient management practices involving soil and foliar applications in enhancing the physiological indices of chickpeas.

Mitigation of cadmium-induced stress in maize via synergistic application of biochar and gibberellic acid to enhance morpho-physiological and biochemical traits

Cadmium (Cd), being a heavy metal, tends to accumulate in soils primarily through industrial activities, agricultural practices, and atmospheric deposition. Maize, being a staple crop for many regions, is particularly vulnerable to Cd contamination, leading to compromised growth, reduced yields, and potential health risks for consumers. Biochar (BC), a carbon-rich material derived from the pyrolysis of organic matter has been shown to improve soil structure, nutrient retention and microbial activity. The choice of biochar as an ameliorative agent stems from its well-documented capacity to enhance soil quality and mitigate heavy metal stress. The study aims to contribute to the understanding of the efficacy of biochar in combination with GA3, a plant growth regulator known for its role in promoting various physiological processes, in mitigating the adverse effects of Cd stress. The detailed investigation into morpho-physiological attributes and biochemical responses under controlled laboratory conditions provides valuable insights into the potential benefits of these interventions. The experimental design consisted of three replicates in a complete randomized design (CRD), wherein soil, each containing 10 kg was subjected to varying concentrations of cadmium (0, 8 and 16 mg/kg) and biochar (0.75% w/w base). Twelve different treatment combinations were applied, involving the cultivation of 36 maize plants in soil contaminated with Cd (T1: Control (No Cd stress; T2: Mild Cd stress (8 mg Cd/kg soil); T3: Severe Cd stress (16 mg Cd/kg soil); T4: 10 ppm GA3 (No Cd stress); T5: 10 ppm GA3 + Mild Cd stress; T6: 10 ppm GA3 + Severe Cd stress; T7: 0.75% Biochar (No Cd stress); T8: 0.75% Biochar + Mild Cd stress; T9: 0.75% Biochar + Severe Cd stress; T10: 10 ppm GA3 + 0.75% Biochar (No Cd stress); T11: 10 ppm GA3 + 0.75% Biochar + Mild Cd stress; T12: 10 ppm GA3 + 0.75% Biochar + Severe Cd stress). The combined application of GA3 and BC significantly enhanced multiple parameters including germination (27.83%), root length (59.53%), shoot length (20.49%), leaf protein (121.53%), root protein (99.93%), shoot protein (33.65%), leaf phenolics (47.90%), root phenolics (25.82%), shoot phenolics (25.85%), leaf chlorophyll a (57.03%), leaf chlorophyll b (23.19%), total chlorophyll (43.77%), leaf malondialdehyde (125.07%), root malondialdehyde (78.03%) and shoot malondialdehyde (131.16%) across various Cd levels compared to the control group. The synergistic effect of GA3 and BC manifested in optimal leaf protein and malondialdehyde levels indicating induced tolerance and mitigation of Cd detrimental impact on plant growth. The enriched soils showed resistance to heavy metal toxicity emphasizing the potential of BC and GA3 as viable strategy for enhancing maize growth. The application of biochar and gibberellic acid emerges as an effective means to mitigate cadmium-induced stress in maize, presenting a promising avenue for sustainable agricultural practices.

Mycorrhizal status of Guarianthe skinneri (Orchidaceae) in urban trees in Tapachula, Chiapas, Mexico

Objective: To isolate and classify morphologically and molecularly mycorrhizal fungi associated with adult plants of Guarianthe skinneri (Bateman) Dressler & W.E. Higgins (Orchidaceae), distributed in different phorophytes, exotic and native trees, in the City of Tapachula, Chiapas, Mexico. Design/Methodology/Approach: We sampled roots from adult plants growing in two native phorophytes, Byrsonima crassifolia (L.) KUNTH and Tabebuia rosea (BERTOL.) BERTERO EX A. DC. and two exotic phorophytes, Terminalia catappa L. and Ficus benjamina L. located in the city's road. By the isolation of mycorrhizal strains, we had diagnosed them by morpho-physiological attributes, and molecularly (Sanger sequencing of the ITS1-4 region). Results: Forty-three fungal strains of two anamorphic mycorrhizal genus Epulorhiza and Ceratorhiza were obtained: 50% of the isolates came from plants growing in the exotic tree T. catappa with undigested pelotons and the highest molecular diversity (three contigs of the genus Tulasnella). Ficus benjamina had one molecular species shared with the native B. crassifolia. Roots growing in the native T. rosea tree, even though few isolates could be purified. Study Limitations/Implications: Even if the research was exploratory, it was possible to highlight the diverse mycorrhizal partners that urban phorophytes of G. skinneri harbor, showing their potential in the ex situ conservation of this species. Findings/Conclusions: The large number of the anamorph Epulorhiza isolates obtained from all phorophytes, reinforces previous observations suggesting that candelaria is preferentially associated with species of the Family Tulasnellaceae.

Evaluating Impacts of Biosynthetic Silver Nanoparticles on Morphophysiological Responses in Barley (Hordeum vulgare L.)

In recent years, nanotechnology has shown promising potential to enhance sustainable agriculture. Besides their use as antifungal and antimicrobial agents, silver nanoparticles (AgNPs) are the most widespread nanomaterials and are found in a capacious range of agrocommercial products. This study was designed to investigate the responses of morphophysiological characteristics in barley (Hordeum vulgare L.) to biologically synthesized silver nanoparticles. Spherical shapes with 8–20 nm size AgNPs at different concentrations (0, 50, 100, 150, 200, and 250 mg/L) were applied to barley plants in a hydroponic system. Following 7 days of sowing, the growth performance, chlorophyll contents, oxidative damage, and the activity level of antioxidant enzymes were quantified in different parts of the plant. The results indicated a remarkable boost in the growth performance and chlorophyll contents of barley plants up to a concentration of 150 mg/L. Interestingly, the levels of proline, lipid peroxidation, enzymes; superoxide dismutase (SOD), catalase (CAT), (APX), and (GR) activities were enhanced significantly in response to all AgNPs treatments. In general, the application of AgNPs substantially improved the growth and related morphophysiological attributes in barley. Our results provide new insights with respect to the effects of AgNPs on barley growth and their potential applications in increasing the performance of other crop species.

Green synthesized nano silica: foliar and soil application provides drought endurance in Eleucine coracana

SiNPs mitigate drought stress in Eleucine coracana by improving its morpho-physiological attributes. SiNPs improved enzymatic and non-enzymatic potential of the plant by boosting its drought tolerance ability.

Rhizospheric nano-remediation salvages arsenic genotoxicity: Zinc-oxide nanoparticles articulate better oxidative stress management, reduce arsenic uptake, and increase yield in Pisum sativum (L.)

Pea (Pisum sativum L.), a legume, has a high nutritional content, but arsenic (As) in the agro-ecosystem poses a significant bottleneck to its yield, especially in South East Asia, by severely hampering ontogeny. The present study proposes a rhizospheric nano-remediation strategy to evade As-genotoxicity and improve crop yield using biogenic zinc-oxide nanoparticles (ZnONPs). Similar to any other source of environmental stress, As-toxicity caused rapid oxidative bursts with deterioration in morpho-physiological attributes (germination rate, shoot length, and root length decreased by 62 %, 16 %, and 14.9 % respectively in the negative control, over normal control). Reactive oxygen species (ROS) accumulation (12.8 and 9-fold increase in leaves and roots) overburdened antioxidative defense, and loss of cellular homeostasis resulted in membrane damage (82.75 % increase) and electrolyte-leakage (2.6-fold increase) in negative control. The study also reveals a significant increase in nuclear area, nuclear fragmentation, and micronuclei formation in root tip cells under As-stress, indicating severe genomic instability and increased programmed cell death (3.3-fold increase in early apoptotic cells) due to leaky plasma membrane and unrepaired DNA damage. Application of ZnONPs significantly reduced As-toxicity in peas due to its adsorption in the rhizosphere, causing diminished As-uptake and better antioxidant response. Improved phytochelatin synthesis enhanced vacuolar sequestration of arsenic, which reduced As-interference. Comparatively better flowering time (7.74–19.36 % reduction in flowering delay) with greater transcript abundance of GIGANTIA (GI), CONSTANS (CO), and FLOWERING LOCUS T (FT) genes; better photosynthetic activity (1.3–1.9-fold increased chlorophyll autofluorescence); increased pollen viability; lesser genotoxicity (decreased tail DNA in comet assay) was noticed. A maximum increase of 37.5 % in pod number and seed zinc content (1.67-fold) was observed while seed arsenic content decreased under ZnONPs treatment. However, the highest dose of ZnONPs (400 mg L−1) induced NP-toxicity in pea plants under our experimental conditions, while optimum stress-alleviation was observed up to 300 mg L−1.

Toxic effects of lead on plants: integrating multi-omics with bioinformatics to develop Pb-tolerant crops.

Lead disrupts plant metabolic homeostasis and key structural elements. Utilizing modern biotechnology tools, it's feasible to develop Pb-tolerant varieties by discovering biological players regulating plant metabolic pathways under stress. Lead (Pb) has been used for a variety of purposes since antiquity despite its toxic nature. After arsenic, lead is the most hazardous heavy metal without any known beneficial role in the biological system. It is a crucial inorganic pollutant that affects plant biochemical and morpho-physiological attributes. Lead toxicity harms plants throughout their life cycle and the extent of damage depends on the concentration and duration of exposure. Higher levels of lead exposure disrupt numerous key metabolic activities of plants including oxygen-evolving complex, organelles integrity, photosystem II connectivity, and electron transport chain. This review summarizes the detrimental effects of lead toxicity on seed germination, crop growth, and yield, oxidative and ultra-structural alterations, as well as nutrient absorption, transport, and assimilation. Further, it discusses the Pb-induced toxic modulation of stomatal conductance, photosynthesis, respiration, metabolic-enzymatic activity, osmolytes accumulation, and antioxidant activity. It is a comprehensive review that reports on omics-based studies along with morpho-physiological and biochemical modifications caused by lead stress. With advances in DNA sequencing technologies, genomics and transcriptomics are gradually becoming popular for studying Pb stress effects in plants. Proteomics and metabolomics are still underrated and there is a scarcity of published data, and this review highlights both their technical and research gaps. Besides, there is also a discussion on how the integration of omics with bioinformatics and the use of the latest biotechnological tools can aid in developing Pb-tolerant crops. The review concludes with core challenges and research directions that need to be addressed soon.

Modulation of morpho-physiological attributes and in situ analysis of secondary metabolites using Raman spectroscopy in response to red and blue light exposure in Artemisia annua

Differential light conditions, such as variations in photoperiod, light quality, and light intensity, play a crucial role as external factors that can influence plant morphogenesis and secondary metabolism. However, there is still a lack of understanding of how Artemisia annua responds to monochromatic and dichromatic light regimes in terms of the different physiological mechanisms that control plant growth and secondary metabolite production. Therefore, the primary aim of this study was to investigate and assess the various physiological parameters, biochemical analysis, and molecular aspects in detail. Therefore, the plantlets were exposed to LED lighting such as monochromatic red light (R), monochromatic blue light (B), white light (W), and a combination of red and blue light (RB, 1:1) at a PPFD (photosynthetic photon flux density) of 200 mol. m−2. s−1 for 10 days. Our results indicate that exposure to RB light resulted in an immense increase in ROS accumulation, flavonoids, lignin, and artemisinin by 4.7-fold, 44%, and 53.4%, respectively, in contrast to W light. Whereas blue light led to increments of 160.2% in phenolic and 107.9% in anthocyanin content. RB and B light also influence the parameters of chlorophyll fluorescence, as well as leaf area, stomatal density, trichome size, antioxidant enzyme activity, and the production of more secondary metabolites to combat oxidative stress. Real-time PCR analysis of biosynthetic pathway-associated genes HMGR, DXR, DXS, FPS, ADS, CYP71AVI, DBR2, ALDH1, and flavonoid key biosynthesis pathway genes PAL, C4H, 4CL, CHS, and F3′H showed the highest increment under RB, light followed by B and R light exposure. Further, RB LED light has significant potential for enhancing natural bio-active compounds as revealed by Raman spectroscopy, such as camphor, limonene, terpene-4-ol, α pinene, 1,8-cineole, β-caryophyllene, artemisinin, kaempferol, luteolin, rutin, and caffeic acid in A. annua. Taken together, red and blue LEDs can serve as significant elicitors for the production of commercially important metabolites.

Effect of melatonin foliar sprays on morphophysiological attributes, fruit yield and quality of Momordica charantia L. under salinity stress

Soil salinity is one of the increasing problems in agricultural fields in many parts of the world, adversely affecting the performance and health of the plants. As a pleiotropic signal and antioxidant molecule in both animals and plants, melatonin has been reported to possess significant roles in combating with stress factors, in general and salt stress, in particular. In this study, the interactive effects of melatonin (0, 75, and 150 μM) and salt stress (0, 50 and 100 mM NaCl) were investigated by assaying the some agronomic, physlogical and biochemical attributes and essential oil compounds of bitter melon (Momordica charantia). The results showed that exogenous melatonin could promote net photosynthetic rate (Pn) and PSII efficiency (Fv/Fm), increase K+ content and activity of antioxidant enzymes and decrease reactive oxygen species, malondialdehyde and Na+ content in stress-submitted seedlings, in comparison to the non-stressed seedlings (p < 0.05). Melatonin increased content of essential oils. Concerning the major compounds of fruits of bitter melon, charantin, momordicin and cucurbitacin were increased with the melatonin treatments, whereas they were critically decreased with the salt stress. In addition, melatonin increased the antioxidant capacity in fruits under non-saline and salinity conditions. Amid the concentrations of melatonin, plants treated with 150 μM of melatonin under either non-saline or saline conditions showed better performance and productivity. Therefore, application of 150 μM melatonin resulted in a significant improvement of salinity tolerance and essential oil compounds in bitter melon plant, suggesting this as an efficient ‘green’ strategy for sustainable crop production under salt stress conditions.

Alleviation of NaCl stress in tomato varieties by promoting morpho-physiological attributes and biochemical characters

Salinity is a significant abiotic stress, affecting plant growth and productivity during all plant developmental stages. Soil salinization due to climate change is increasing crop loss every year. Salinity is considered the most important abiotic stress limiting crop production and plants are known to be able to continue to survive under this stress by involving many mechanisms. Vegetable crops face huge yield losses due to abiotic stress. Salt stress creates physiological drought in plants affecting morphology and alters physiological functions that harm plants through various processes. Tomato is an essential annual crop providing human food worldwide. It is estimated that by the year 2050 > 50% of the arable land will become saline and, in this respect, in recent years, researchers have focused their attention on studying how tomato plants behave under various saline conditions. This study was conducted to observe the effects of NaCl salinity on four tomato (Lycopersicum esculentum L.) varieties in a pot experiment. Morphological and physio-biochemical properties of four tomato varieties (Rio Grande, Nadir, Bonita, and 19299) were exposed to NaCl-salinity (0, 100, 200, and 300 mM) through irrigation. All the varieties have differential responses to different levels of salt. Salinity stress reduced growth parameters in all varieties as compared to control plants. Plant Variety 4 (19299) showed significantly increased growth (root length, shoot length, number of roots, number of leaves, leaf area, plant fresh and dry weight) and physiological attributes (photosynthetic pigments, total soluble sugars, and total proteins) as compared to other varieties. Variety 4 (19299) has better protection against salt stress by increasing pigment content and enzymatic activity under salt stress. Antioxidants (peroxidase, catalase, and superoxide dismutase) were increased to maximum in variety 3 (Bonita) which is the most susceptible variety among all other varieties. Malondialdehyde (MDA) content, lycopene, anthocyanin, and H2O2 also increased in Variety 3 as compared to other varieties and control plants. Bonita variety showed maximum reduction in root length, shoot length, number of roots, fresh and dry matter content as well as in leaf area while comparing with other three varieties. The study revealed that the 19299 variety is salt tolerant, Rio Grande and Nadir are intermediates while the Bonita variety is susceptible to salt stress.

Kenaf and soybean intercropping affects morpho-physiological attributes, antioxidant capacity and copper uptake in contaminated soil

Kenaf and soybean intercropping affects morpho-physiological attributes, antioxidant capacity and copper uptake in contaminated soil

Silicon and Strigolecton Application Alleviates the Adversities of Cadmium Toxicity in Maize by Modulating Morpho-Physiological and Antioxidants Defense Mechanisms

Cadmium (Cd) toxicity is a serious threat to agronomic crop productivity worldwide. It raises severe concerns about the food and nutrient security required to meet the demands of a rapidly growing population, while also creating grave challenges for agriculture. Silicon (Si) and strigolecton (SL) are reported to impart multiple benefits to plants exposed to abiotic stress. Therefore, the current experiment was performed to evaluate the effects of silicon (4.0 mM) and strigolecton (20 µM) on the amelioration of cadmium (25 mg kg−1 soil) stress in maize seedlings via intervention in morphological attributes, photosynthetic pigments, enzymatic antioxidant mechanisms, and osmolyte accumulation. The results indicated that morphological attributes and photosynthetic pigments were significantly reduced in Cd-exposed seedlings. However, foliar application of Si and SL, both individually and in combination, significantly improved the growth attributes and photosynthetic pigments of maize seedlings under both control and Cd-stress conditions. Exposure of maize seedlings to Cd stress increased H2O2 levels, malondialdehyde content, and electrolyte leakage and reduced cell membrane stability. These effects were significantly negated by Si and SL supplementation, both individually and in combination. Moreover, enzymatic antioxidants, including catalase, superoxide dismutase, peroxidase, and ascorbate peroxidase, were activated after Cd stress, but their activity was further increased with foliar application of Si or SL. In Cd-contaminated seedlings, the combined application of Si and SL enhanced soluble proline, sugars, and total phenolic contents as compared to the control treatment. Furthermore, Si and SL applications increased Si accumulation in Cd-exposed seedlings and decreased Cd uptake. It was concluded that the combined application of Si and SL improved Cd tolerance in maize seedlings by modulating morpho-physiological attributes, photosynthetic pigments, and osmolytes accumulation, and by supporting the antioxidant defense system. The findings of this study suggest that Si and SL could be safe and effective strategies for reducing Cd toxicity in maize seedlings.

Multivariate analysis of the salinity-induced alterations in morphology, physiology, nodulation, and yield in two contrasting mungbean varieties

Changes were estimated in the morphology, physiology, photosynthesis, nodulation, and yield in two mungbean varieties ‘PKV AKM 12-28’ and ‘VBN (Gg)3’ under salt stress (0, 75, 100, and 125 mM NaCl) for 15, 30, and 45 days. Multivariate modelling was used to analyse results to explore complex data and to visualize time and concentration-dependent modulations. Principal component analysis showed modulations in morpho-physiological attributes such as shoot length, root length, the number of secondary branches, shoot fresh weight, root fresh weight, shoot dry weight, root dry weight and leaf area; photosynthetic attributes such as chlorophyll ‘a’, chlorophyll ‘b’, total chlorophyll, total carotene and total anthocyanine content; nodulation attributes such as nodules per plant, size of the nodule, and fresh weight per nodule, and yield attributes such as number of pods per plant, fresh weight per pod, and seed characteristics such as the number of seeds per pod and fresh weight per 1000 seeds are key traits affected by salt stress and can be used as indicators. Discriminant analysis identified modulations in morpho-physiological attributes such as root length, leaf area, root fresh weight, shoot fresh weight, shoot dry weight, shoot length and photosynthetic attributes such as chlorophyll-a content, and mean nodule weight as discriminating variables at different salt concentrations. Besides, it identified modulations in morpho-physiological attributes such as root length, root fresh weight, photosynthetic attributes such as total anthocyanin content and total chlorophyll content, nodulation attribute such nodule size and nodule weight, and yield attributes such as pod number and number of seeds per pod are discriminating variables at various durations of salt stress. Principal component analysis and discriminant analysis identified ‘PKV-AKM 12-28’ as salt-tolerant and ‘VBN (Gg)3’ as salt-susceptible varieties. Multiple correlation analysis identified significant correlations among morphological, physiological, photosynthetic, nodulation and yield parameters.

Effect of Biochar Application on Morpho-Physiological Traits, Yield, and Water Use Efficiency of Tomato Crop under Water Quality and Drought Stress.

The use of saline water under drought conditions is critical for sustainable agricultural development in arid regions. Biochar is used as a soil amendment to enhance soil properties such as water-holding capacity and the source of nutrition elements of plants. Therefore, the experiment was conducted to evaluate the effects of biochar application on the morpho-physiological traits and yield of tomatoes under combined salinity and drought stress in greenhouses. There were 16 treatments consist two water quality fresh and saline (0.9 and 2.3 dS m-1), three deficit irrigation levels (DI) 80, 60, and 40% addition 100% of Evapotranspiration (ETc), and biochar application by rate 5% (BC5%) (w/w) and untreated soil (BC0%). The results indicated that the salinity and water deficit negatively affected morphological, physiological, and yield traits. In contrast, the application of biochar improved all traits. The interaction between biochar and saline water leads to decreased vegetative growth indices, leaf gas exchange, the relative water content of leaves (LRWC), photosynthetic pigments, and yield, especially with the water supply deficit (60 and 40% ETc), where the yield decreased by 42.48% under the highest water deficit at 40% ETc compared to the control. The addition of biochar with freshwater led to a significantly increased vegetative growth, physiological traits, yield, water use efficiency (WUE), and less proline content under all various water treatments compared to untreated soil. In general, biochar combined with DI and freshwater could improve morpho-physiological attributes, sustain the growth of tomato plants, and increase productivity in arid and semi-arid regions.

Physiological Changes and Nutritional Value of Forage Clitoria Grown in Arid Agro-Ecosystem as Influenced by Plant Density and Water Deficit

Forage crop productivity has lately reduced in countries located in arid and semi-arid regions worldwide due to intensive consumption and the successive years of drought. This problem is exacerbated by the progress of water scarcity. Thus, the current study is aimed at improving the forage productivity and quality of clitoria as a leguminous fodder crop to be involved in crop rotations under low water supply conditions. As an attempt for facing the drought issue, a two-year (SI and SII) field experiment was conducted to evaluate the influence of irrigation pattern (IP) and plant density (PD) on clitoria morpho-physiological attributes, nutritive value, productivity, and irrigation water-use efficiency (IWUE) in two growth cycles (GCI and GCII). Based on the soil water depletion method, three irrigation patterns of 100% (IP0%, full irrigation), 80% (IP20%), and 60% (IP40%) were applied. The tested plant densities were 33 (PD33), 22 (PD22), and 17 (PD17) plants m−2. Findings revealed that IP0% × PD22 was the efficient treatment for enhancing the physio-biochemical attributes. However, in SI IP0% × PD22 statistically at par (p≥0.05) with IP0% × PD33, IP20% × PD22, and IP20% × PD17 (for chlorophyll content in GCI); IP0% × PD17 and IP20% × PD22 (for leaf relative water content in GCII); and IP0% × PD33, IP20% × PD33, and IP20% × PD22 (for cell membrane stability index in GCII). Along the two seasons, IP40% × PD33 was the potent practice for producing the highest leaf: stem ratio in both GCI (2.07 and 1.78) and GCII (1.18 and 0.96). Under IP40%, PD33 treatment recorded the greatest protein content in both GCI (24.1–27.0%) and GCII (21.7–19.5%) of SI and SII equaling PD22 in GCII (21.2–18.9%) of both seasons and PD17 in both GCI (24.0%) and GCII (21.5%) of SI and GCII (19.3%) of SII. The best aggregate protein yield for SI and SII was obtained under IP20% × PD33 interaction (1.36 and 1.40 t ha−1) without significant difference (p≥0.05) with IP0% × PD33 or IP40% × PD33 interactions. The greatest aggregate dry forage yield was observed in SI under IP0% or IP20% combined with PD33 (7.77 and 7.52 t ha−1) which did not differ significantly (p≥0.05). It could be concluded that irrigation by 80% water of full irrigation was found to be an efficient water-saving tactic coupled with adjusting the plant density of 33 plants m−2, which improved clitoria forage quantitative and qualitative properties, in addition to enhancing IWUE. Since leaf relative water content and cell membrane stability index decreased and proline increased in plant tissues under deficit water, clitoria is plant considered a moderately drought tolerant. Thus, clitoria is a promising plant could be successfully grown under arid agro-ecosystems.

Biocontrol Efficacy of Endophyte Pseudomonas poae to Alleviate Fusarium Seedling Blight by Refining the Morpho-Physiological Attributes of Wheat.

Some endophyte bacteria can improve plant growth and suppress plant diseases. However, little is known about the potential of endophytes bacteria to promote wheat growth and suppress the Fusarium seedling blight pathogen Fusarium graminearum. This study was conducted to isolate and identify endophytic bacteria and evaluate their efficacy for the plant growth promotion and disease suppression of Fusarium seedling blight (FSB) in wheat. The Pseudomonas poae strain CO showed strong antifungal activity in vitro and under greenhouse conditions against F. graminearum strain PH-1. The cell-free supernatants (CFSs) of P. poae strain CO were able to inhibit the mycelium growth, the number of colonies forming, spore germination, germ tube length, and the mycotoxin production of FSB with an inhibition rate of 87.00, 62.25, 51.33, 69.29, and 71.08%, respectively, with the highest concentration of CFSs. The results indicated that P. poae exhibited multifarious antifungal properties, such as the production of hydrolytic enzymes, siderophores, and lipopeptides. In addition, compared to untreated seeds, wheat plants treated with the strain showed significant growth rates, where root and shoot length increased by about 33% and the weight of fresh roots, fresh shoots, dry roots, and dry shoots by 50%. In addition, the strain produced high levels of indole-3-acetic acid, phosphate solubilization, and nitrogen fixation. Finally, the strain demonstrated strong antagonistic properties as well as a variety of plant growth-promoting properties. Thus, this result suggest that this strain could be used as an alternate to synthetic chemicals, which can serve as an effective method of protecting wheat from fungal infection.

Comparative Effects of Hydropriming and Iron Priming on Germination and Seedling Morphophysiological Attributes of Stay-Green Wheat.

Seed priming is considered to play an essential role in the overall improvement of agricultural crops. The current research work was carried out in order to investigate the comparative effects of hydropriming and iron priming on the germination behavior and morphophysiological attributes of wheat seedlings. The experimental materials consisted of three wheat genotypes including a synthetically derived wheat line (SD-194), stay-green wheat genotype (Chirya-7), and conventional wheat variety (Chakwal-50). The treatments included hydro (distilled and tap water)- and iron priming (10 and 50 mM) of wheat seeds for 12 h duration. Results indicated that both priming treatment and wheat genotypes exhibited highly different germination and seedling characteristics. These included germination percentage, root volume, root surface, root length, relative water content, chlorophyll content, membrane stability index, and chlorophyll fluorescence attributes. Furthermore, the synthetically derived line (SD-194) was the most promising in majority of the studied attributes by exhibiting a high germination index (2.21%), root fresh weight (7.76%), shoot dry weight (3.36%), relative water content (19.9%), chlorophyll content (7.58%), and photochemical quenching coefficient (2.58%) when compared with stay-green wheat (Chirya-7). The study also found that hydropriming with tap water and priming wheat seeds with low concentrations of iron yielded better results when a comparison was made with wheat seeds primed at high concentrations of iron. Therefore, wheat seed priming with tap water and iron solution for 12 h is recommended for optimum wheat improvement. Furthermore, current findings suggest that seed priming may have the prospect of an innovative and user-friendly approach for wheat biofortification with the aim of enhanced iron acquisition and accumulation in grains.

Waterlogging stress reduces cowpea (Vigna unguiculata L.) genotypes growth, seed yield, and quality at different growth stages: Implications for developing tolerant cultivars under field conditions

Waterlogging is a significant abiotic stress that reduces the oxygen supply to roots in the rhizosphere, impairing plant growth and development. Cowpea is highly sensitive to waterlogging, and their grain yield is affected by genotype and growth stage. Understanding the growth and physiological responses of cowpea to waterlogging stress is crucial for developing strategies to improve crop yield in waterlogged environments. In this two-year field trial, we quantified the impact of ten days of waterlogging on morpho-physiological attributes, seed yield components, and seed quality of two cowpea genotypes (UCR 369 and EpicSelect.4) at different growth stages. Waterlogging during the reproductive (R2) growth stage had the most substantial impact on cowpea, with an average reduction of leaf area by 65%, chlorophyll content by 39%, stomatal conductance (gs) by 93%, and photochemical efficiency by 32% compared to non-waterlogged plants. These effects were less pronounced during the vegetative (V4) and physiological maturity (R7) growth stages. Lower photosynthetic capacity resulted in reduction of biomass accumulation, pod dry weight, number of pods per plant, and seed weight under waterlogging. EpicSelect.4 was more sensitive to waterlogging at the R2 stage, showing a greater reduction in seed yield (58%) compared to UCR 369 (46%). Additionally, UCR 369 maintained seed protein content under waterlogging conditions, while it decreased by 8% in EpicSelect.4 seeds. Overall, UCR 369 was more tolerant to waterlogging stress than EpicSelect.4, with the most apparent effect of waterlogging on yields occurring at the R2 stage due to the high energy demands of the cowpea reproductive process. Our study highlights the importance of selecting cowpea genotypes with greater tolerance to waterlogging stress during the reproductive stage to mitigate the negative effects of waterlogging on seed yield in flood-prone environments. These results provide valuable insights into the mechanisms of cowpea's responses to waterlogging stress and can aid in developing strategies for improving cowpea yield in waterlogged environments, which are expected to become more frequent due to climate change.

Modulation of Antioxidant Defense Mechanisms and Morpho-Physiological Attributes of Wheat through Exogenous Application of Silicon and Melatonin under Water Deficit Conditions

Although the individual influences of silicon (Si) and melatonin (MT) have been widely studied under various abiotic stresses, little is known about their interaction under drought stress. In this study, an experiment in pots was carried out to investigate the potential of an individual or combined foliar application of silicon (Si) and melatonin (ML) (control (ck), water spray, 4.0 mM Si, 200 µM ML, and 4.0 mM Si + 200 µM ML) on wheat grown at two different water-holding capacity levels (80% well-water condition and 40% drought stress) in order to check of grain yield and some important physiological characteristics. Under drought stress conditions, grain yield and yield attributes, water content and photosynthetic efficiency of wheat crops were significantly decreased. Application of Si+ ML significantly improved leaf pigments (Chl a, Chl b and Chll a + b), leaf relative water content (RWC), proline, total soluble sugars, and total soluble protein. As well as, the activities of important antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD), peroxidase (POD) and ascorbate peroxidase (APX) were effectively boosted through the combined application of Si + ML. This improvement was correlated with an obvious decrease in the levels of MDA, H2O2, and electrolyte leakage and increased water use efficiency. Conclusively, the combination of Si + ML significantly enhanced the 20.21% yield and various morpho-physiological attributes of drought-stressed wheat plants and can be recommended as a promising treatment to enhance wheat productivity in drought-affected regions. Additionally, the results of this study may open up a whole new area of research opportunities at the transcriptional level to further understand the mechanisms underlying how Si + ML integrates and interacts with plants under drought stress.