Induced Water Stress Research Articles

Impact of Fire Recurrence and Induced Water Stress on Seed Germination and Root Mitotic Cell Cycle of Pinus pinaster Aiton

Climate change will increase the frequency of drought, heat waves, and wildfires. We intended to analyse how fire recurrence and/or induced water stress can affect seed germination and root cell division in Pinus pinaster Aiton. Seeds from stands with no prior fire history and from post-fire regeneration (in areas burnt once, twice, and thrice) in northern Portugal were germinated in distilled water (control) and polyethylene glycol (PEG) to simulate water stress for four weeks, followed by a recovery period. Roots were analysed cytogenetically. The germination index of the Pinus pinaster seeds was not statistically influenced by the induction of osmotic stress, nor by the fire recurrence of the stands. The mean germination time (MGT) was 10–29 days and 1–36 days for the stress and recovery periods, respectively, and increased with PEG concentration. The 20% PEG treatment inhibited root growth after germination. The 10% PEG treatment induced a high frequency of cytogenetic anomalies, mostly in the sites which experienced fire exposure. While fire recurrence did not affect the germination rate, it seemed to reduce the water stress response, negatively impacting cell division and impair root growth.

Bunyaviruses Affect Growth, Sporulation, and Elicitin Production in Phytophthora cactorum.

Phytophthora cactorum is an important oomycetous plant pathogen with numerous host plant species, including garden strawberry (Fragaria × ananassa) and silver birch (Betula pendula). P. cactorum also hosts mycoviruses, but their phenotypic effects on the host oomycete have not been studied earlier. In the present study, we tested polyethylene glycol (PEG)-induced water stress for virus curing and created an isogenic virus-free isolate for testing viral effects in pair with the original isolate. Phytophthora cactorum bunya-like viruses 1 and 2 (PcBV1 & 2) significantly reduced hyphal growth of the P. cactorum host isolate, as well as sporangia production and size. Transcriptomic and proteomic analyses revealed an increase in the production of elicitins due to bunyavirus infection. However, the presence of bunyaviruses did not seem to alter the pathogenicity of P. cactorum. Virus transmission through anastomosis was unsuccessful in vitro.

Modeling the upshots of induced temperature and water stress on germination and seedlings length of radish (Raphanus sativus L.) via hydrothermal time model

Radish (Raphanus sativus L.), a representative of the Brassicaceae family, is an extensively cultivated root vegetable across the world. Thermal time (TT), hydro time (HT), and hydrothermal time (HTT) models can be used to characterize the response of seed germination rate to temperature (T) and water potential (ψ). The germination behavior of radish was investigated throughout a range of constant temperatures and water potentials to evaluate the effectiveness of hydro-thermal time model and offer a data set of germination thresholds and parameters. The study was intended to simultaneously inspect the radish seed germination (SG) pattern, base water potentials (ψb(50)) and cardinal temperatures across varying temperatures (Ts) and PEG-6000 water potentials (Ψs) via the hydrothermal time (HTT) model. In a laboratory experiment Raphanus sativus L. seeds were germinated at four constant Ts of 15, 20, 30 and 40 °C under four different water potentials (ψs) of 0, − 0.2, − 0.4 and − 0.6 MPa. Germination decreased significantly at (p ≤ 0.01) from 40% at 15 °C in − 0.2 MPa to 13% in − 0.8 MPa at 40 °C. The results also revealed that radish was more sensitive to ψ than T (p ≤ 0.01). As per the significance level of the model attributes (R2: 0.527), the average cardinal temperatures were 15, 20 and 40 °C for the base (Tb), optimal (To) and ceiling (Tc) temperatures respectively. Germination energy (GE), germination rate index (GRI), germination percentage (G%), germination index (GI), mean moisture content (MMC), seed vigor index 1 and 2 (SVI-1 and SVI-2), were recorded maximum in control condition at 15 and 20 °C and minimum at − 0.8 MPa at 40 °C. The model applied here, and its attributes, may be used as a prediction tool in different SG simulation studies, each with its own set of strengths and drawbacks. The hydrothermal constant investigates the interaction influence of T and ψ on germination under diverse ecological settings using germination data, cardinal temperatures, and statistical analysis.

Tracheid buckling buys time, foliar water uptake pays it back: Coordination of leaf structure and function in tall redwood trees.

Tracheid buckling may protect leaves in the dynamic environments of forest canopies, where rapid intensifications of evaporative demand, such as those brought on by changes in light availability, can result in sudden increases in transpiration rate. While treetop leaves function in reliably direct light, leaves below the upper crown must tolerate rapid, thermally driven increases in evaporative demand. Using synchrotron-based X-ray microtomography, we visualized impacts of experimentally induced water stress and subsequent fogging on living cells in redwood leaves, adding ecological and functional context through crown-wide explorations of variation in leaf physiology and microclimate. Under drought, leaf transfusion tracheids buckle, releasing water that supplies sufficient temporal reserves for leaves to reduce stomatal conductance safely while stopping the further rise of tension. Tracheid buckling fraction decreases with height and is closely coordinated with transfusion tissue capacity and stomatal conductance to provide temporal reserves optimized for local variation in microclimate. Foliar water uptake fully restores collapsed and air-filled transfusion tracheids in leaves on excised shoots, suggesting that trees may use aerial water sources for recovery. In the intensely variable deep-crown environment, foliar water uptake can allow for repetitive cycles of tracheid buckling and unbuckling, protecting the tree from damaging levels of hydraulic tension and supporting leaf survival.

The response of the laboratory cultivated Quercus coccifera plants to an artificial water stress

Seedlings of Quercus coccifera were planted to grow in a series of liquid culture–mediums of gradually increasing PolyEthylene Glycol (PEG) concentration. The induced water stress strongly affected plant growth. As the PEG concertation raised the growth of the stems and roots was retarded, roots appeared to rely on the distribution of the phenolic containing cells for retaining a water flow, phenolic synthesis dramatically increased in the leaves and shifted to the production of condensed forms, oxidative stress appeared, thus, Reactive Oxygen Species (ROS) steeply increased, pigment absorption weakened and a remarkable rate of L-Dopa DeCarboxylase (DDC) expression was triggered. Phytochemical investigation via Liquid Chromatography – High Resolution Mass Spectrometry (LC-HRMS) contributed to the detailed identification of the phenolic compounds in leaf extracts, and confirmed their profiles and metabolism both via biochemical detection and anatomical distribution the microscopic findings. Totally 25 compounds were identified showing qualitative and quantitative alternations in different PEG treatments.

Influence of Meteorological Conditions on Artificial Ice Reservoir (Icestupa) Evolution

Since 2014, mountain communities in Ladakh, India have been constructing dozens of Artificial Ice Reservoirs (AIRs) by spraying water through fountain systems every winter. The meltwater from these structures is crucial to meet irrigation water demands during spring. However, there is a large variability associated with this water supply due to the local weather influences at the chosen location. This study compared the ice volume evolution of an AIR built in Ladakh, India with two others built in Guttannen, Switzerland using a surface energy balance model. Model input consisted of meteorological data in conjunction with fountain discharge rate (mass input of an AIR). Model calibration and validation were completed using ice volume and surface area measurements taken from several drone surveys. The model was successful in estimating the observed ice volume evolution with a root mean square error within 18% of the maximum ice volume for all the AIRs. The location in Ladakh had a maximum ice volume four times larger compared to the Guttannen site. However, the corresponding water losses for all the AIRs were more than three-quarters of the total fountain discharge due to high fountain wastewater. Drier and colder locations in relatively cloud-free regions are expected to produce long-lasting AIRs with higher maximum ice volumes. This is a promising result for dry mountain regions, where AIR technology could provide a relatively affordable and sustainable strategy to mitigate climate change induced water stress.

Characterisation and Effects of Different Levels of Water Stress at Different Growth Stages in Malt Barley under Water-Limited Conditions.

Malt barley is typically grown in dryland conditions in South Africa. It is an important grain after wheat, but little is known about its water requirements and, most importantly, how it responds to water stress. Determining when water stress sets in and how malt barley responds to water deficit during its growing season is crucial for improved management of crop water requirements. The objectives of this study were to evaluate the response of transpiration (T), stomatal conductance (SC), and leaf water potential (LWP) to water stress for different growth stages of malt barley and to characterise water stress to different levels (mild, moderate, and severe). This was achieved by monitoring the water stress indicators (soil- and plant based) under greenhouse conditions in well-watered and water-stressed lysimeters over two seasons. Water stress was characterised into different levels with the aid of soil water content ‘breaking points’ procedure. During the first season, at the end of tillering, flag leaf, and milk/dough growth stages, which represent severe water stress, plant available water (PAW) was below 35%, 56%, 14%, and 36%, respectively. LWP responded in accordance to depletion of soil water during the growing season, with the lowest recorded value to −5.5 MPa at the end of the milk/dough growth stage in the first season. Results also show that inducing water stress resulted in high variability of T and SC for both seasons. In the second season, plants severely stressed during the anthesis growth stage recorded the least total grains per pot (TGPP), with 29.86 g of grains. The study suggests that malt barley should be prevented from experiencing severe water stress during the anthesis and milk/dough stages for optimum malt barley production. Quantification of stress into different levels will enable the evaluation of the impact of different levels of stress on the development, growth, and yield of barley.

Polyethylene Gycol (PEG) Induced Water Stress in Four Different Genotypes of Pea Seedlings and Evaluation of The Induced Defense Mechanism

The present work was undertaken on artificially induced water stress on pea seedlings under in vitro conditions in order to select the drought tolerant line. Artificial water stress was induced with PEG-6000 on 15-day old seedlings of four varieties for 4, 8 and 12 days. The activities of antioxidative enzymes like peroxidase, catalase, ascorbate peroxidase, glutathione reductase and superoxide dismutase were assayed in the stressed and control plants. POX activity was increased in the initial stages of stress, but its activity was decreased significantly on the 12th day in all the varieties. APOX also showed a similar trend but the maximum activity was noted in Var 3 on the 8th day. CAT activity decreased in var 1 and var 2 when compared with the control, which, however, increased significantly in var 3 and var 4. A slight increase in the GR activity was observed in var 1 and var 2 at the initial stages of the drought stress but its activity decreased significantly on the 12th day in both these varieties when compared with control plants. However, its activity also increased steadily in var 3 and var 4. Maximum SOD activities were noted on the 4th day of drought stress in all four varieties but its activities decreased steadily on the subsequent 8th and 12th days when compared with control. When antioxidative activities were compared among the four varieties, var 3 and var 4 showed maximum increase in antioxidant activity during the period of drought stress. Among the four varieties, var 3 and var 4 showed greater accumulation of H2O2 during the stress days and were maximum at 12th day. Lipid peroxidation also increased in the same varieties. Maximum proline content was noted in both the root and leaf of var 3, followed by var 4. It was further noted that the chlorophyll content decreased significantly in all four varieties in subsequent longer drought stresses. The accumulation of proline content was steadily higher with an increase in the stress length in all the four varieties. During the drought stress, all the varieties showed an increase in ascorbate content but, it was maximum in var 4 followed by var 3 and the least ascorbate was noted in var 1. The present findings indicate that water stress induces oxidative stress in all the four varieties. However, antioxidative mechanisms were found to be more pronounced in var 4 which, therefore, may be considered as the most tolerant to drought stress.

Effects of irrigation systems on yield and physical characteristics of date (Phoenix dactylifera .L) cv. ‘Medjool’

The shortage of irrigation water pooled with the effect of climate change and inadequate management in oases; affects the sustainability of the oasis ecosystem. Irrigation, as practiced in these oases, is not conducted according to the real water requirements of the crops, this management can induce water stress which affects the physical characteristics of the dates cultivated and consequently yield production, or on the contrary a significant water intake and a waste of the resource. This study investigated two irrigation systems; drip-irrigation, which is currently applied under date palms in the Moroccan oases, and the newly introduced underground irrigation (Micro-porous irrigation) .The aim of this work, was to assess the effects of different types of irrigation system on yield and physical quality parameters of ‘Medjool’ dates. Fruit quality assessment including fruit weight, length, breadth, pulp thickness, stone weight, length, breadth, number and average weight of bunches fruit per tree were evaluated, to identify the most effective irrigation system for date palm.

Comparative analysis of iron oxide nanoparticles synthesized from ginger (Zingiber officinale) and cumin seeds (Cuminum cyminum) to induce resistance in wheat against drought stress

In the present study, iron oxide nanoparticles (Fe3O2-NPs) synthesized from ginger (Zingiber officinale) and cumin seeds (Cuminum Cyminum L.) extracts were investigated to reveal their potential to enhance the growth and drought resistance of wheat plants under drought stress. In an In Vitro experiment, four different concentrations for Fe3O2-NPs (0.3 mM, 0.6 mM, 0.9 mM, and 1.2 mM) of ginger and cumin seeds were tested. Among all the concentrations tested, ginger Fe3O2-NPs (0.6 mM) and cumin seeds Fe3O2-NPs (1.2 mM) were more effective to enhance wheat germination, biomass, and survival percentage under drought stress and irrigated conditions than the non-treated control plant. In a pot experiment, wheat plants under induced water stress showed marked up-regulation in the biochemical resistance mechanisms when treated with ginger Fe3O2-NPs (0.6 mM) and cumin seeds Fe3O2-NPs (1.2 mM) than the non-treated control. Cumin seeds Fe3O2-NPs (1.2 mM) were more effective than ginger Fe3O2-NPs (0.6 mM) in ameliorating adverse effects of drought stress in wheat. Results demonstrated that cumin seeds Fe3O2-NPs (1.2 mM) exhibited a higher increase in chlorophyll a, b and carotenoids (72%, 265% and 96% respectively), proline (127%), superoxide dismutase (115%), peroxidase (43.8%), ascorbate peroxidase (44.6%). This also showed higher reduction in lipid peroxidation, electrolyte leakage and increased soluble sugars and total Fe content in the roots and shoots than non-treated plants under drought. Hence, nano-priming can be considered an effective strategy for sustainable food production in marginal soils.

Rapid Screening of Small Millet Varieties for Seedling Stage Drought Stress Tolerance

Aim: Drought is one of the most important abiotic stresses that affect the yield of crops globally. The present investigation was conducted to identify small millet genotypes tolerant to seedling stage drought stress.
 Study Design: The experiment was laid out in Completely Randomized Design (CRD) with three replications with genotypes and stress treatments as factors.
 Place and Duration of Study: It was carried out at Department of millets, Centre for plant breeding and genetics, Tamil Nadu Agricultural University, Coimbatore, during 2019.
 Methodology: Ten varieties of various small millets, CO 7 (foxtail millet), CO 4 and ATL 1 (little millet), CO 15 and CO 9 (finger millet), ATL 1 and CO (PV) 5 (proso millet), MDU 1 and CO 2 (barnyard millet) and CO 3 (kodo millet), were used for the study. In vitro screening of the seedlings in Polyethylene Glycol (PEG)-induced water stress at four levels (0, -3, -5 and -7 bars) were carried out based on germination percent, shoot and root length, plant height stress tolerance index (PHSI), root length stress tolerance index (RLSI) and seedling vigour index (SVI).
 Results: Analysis of variance of the genotypes and PEG treatments revealed significant variation for genotypes, treatments and genotype x treatment interactions at P< 0.001. A declining trend for germination percent, shoot length and root length was observed as the stress levels were increased. However, at mild and moderate stress root length was slightly increased. Under mild (-3 bars) and high stress (-7 bars), CO 7 (foxtail millet) recorded the highest SVI percent over control values (165% and 65% respectively). Under moderate stress CO 4 (little millet) recorded the highest SVI (191%). The lowest SVI values under high stress, 4% and 8%, were recorded for ATL 1 (little millet) and CO 3 (kodo millet) respectively.
 Conclusion: Based on invitro screening of small millet varieties for seedling stage water stress, foxtail millet variety CO 7 and kodo millet variety CO 3 can be concluded as the tolerant and susceptible varieties respectively. Further a controlled field experiment may be carried out to understand the field level tolerance of the varieties and their growth stages to drought.

Seed priming with Mg(NO3)2 and ZnSO4 salts triggers physio-biochemical and antioxidant defense to induce water stress adaptation in wheat (Triticum aestivum L.)

Wheat is a widely grown cereal crop that provides >20% daily protein intake and calories worldwide. Drought stress drastically affects the crucial physiological (relative water content; RWC), biochemical (proline content), and molecular attributes in wheat plants from germination to maturity stage and ultimately reduces the yield and quality traits. Given this, the present work was conducted to know the effect of salt seed priming on wheat crop. For this, we have used two wheat variety HUW-468 (V1), and HUW-510 (V2) primed with water (T2), Mg(NO3)2 (T3), ZnSO4 (T4), and combinations of Mg(NO3)2 and ZnSO4 salt (T5) with non-primed seed (T1) under water stress (W1) and control (W0) conditions. We have observed significant differences in plant height (84 to 90 cm), leaf number, total leaf area (431.82 to 505.46 cm2 plant−1), relative water content, chlorophyll content (4.78 to 5.86 mg g−1fresh weight), membrane stability index (MSI) (56.25 to 61.42%), superoxide dismutase (SOD) activity (133.47 to 150.10), MDA content, proline content (101.64 to 100.46), nitrate reductase activity (NRA), and nutrient (N, Zn, and Fe) contents under control and stress conditions. These results concluded that seed priming with a combination of Mg(NO3)2 and ZnSO4 salt is best for improved wheat crop traits under drought stress compared to individual salt and non-priming treatments. Overall, this analysis elucidated that seed priming strengthens the antioxidant capacity under drought conditions by enhancing antioxidant enzymes and alleviating oxidative stress.

Crop Regulation in Pomegranate (Punica granatum L.) through Induced Water Stress and Ethrel Application

The present investigation was carried out at ICAR-CIAH, Bikaner, Rajasthan, India during 2017 to 2019 to regulate crop production in pomegranate at the desired period with higher number of bisexual flower for higher quality fruit yield and to minimize fruit splitting through water stress, pruning and ethrel application. Pooled data analysis revealed that horticultural interventions, chemical treatments and their interactions significantly improved plant volume, bisexual flower number, maturity index, fruit yield with significant reduction in fruit splitting, mite and fungal spot incidence. Among different treatment combinations, maximum canopy volume, number of bisexual flowers, maturity index, fruit yield and lower fruit splitting were recorded (8.56 m3, 85.11 plant-1, 47.81, 124.01 q ha-1 and 1.87 kg plant-1) in withholding irrigation during June+pruning+thinning+ethrel 2 ml l-1 as compared to absolute control (3.41 m3, 75.62 plant-1, 33.35, 85.66 q ha-1 and 2.41 kg plant-1), respectively. The mite and fungal spot incidence were recorded minimum (4.72 and 8.50%) in withholding irrigation during June+pruning+thinning+ethrel 3 ml l-1 application in comparison to maximum recorded in absolute control (29.73 and 33.68%), respectively. Therefore, it can be concluded that withholding irrigation during June+pruning+thinning with ethrel 2 ml l-1 treatment significantly improved quality fruit yield with higher number of bisexual flowers and reduced fruit splitting through induction of flowering and fruit growth during optimal climatic conditions.

Detecting drought regulators using stochastic inference in Bayesian networks

Drought is a natural hazard that affects crops by inducing water stress. Water stress, induced by drought accounts for more loss in crop yield than all the other causes combined. With the increasing frequency and intensity of droughts worldwide, it is essential to develop drought-resistant crops to ensure food security. In this paper, we model multiple drought signaling pathways in Arabidopsis using Bayesian networks to identify potential regulators of drought-responsive reporter genes. Genetically intervening at these regulators can help develop drought-resistant crops. We create the Bayesian network model from the biological literature and determine its parameters from publicly available data. We conduct inference on this model using a stochastic simulation technique known as likelihood weighting to determine the best regulators of drought-responsive reporter genes. Our analysis reveals that activating MYC2 or inhibiting ATAF1 are the best single node intervention strategies to regulate the drought-responsive reporter genes. Additionally, we observe simultaneously activating MYC2 and inhibiting ATAF1 is a better strategy. The Bayesian network model indicated that MYC2 and ATAF1 are possible regulators of the drought response. Validation experiments showed that ATAF1 negatively regulated the drought response. Thus intervening at ATAF1 has the potential to create drought-resistant crops.

↵​Impact of A Selected Mycorrhizal Complex and A Rhizobacterial Species on Tomato Plants’ Growth under Water Stress Conditions

Background: Plant strategies for adapting to drought could be improved by associations between plant roots and soil microorganisms, including arbuscular mycorrhizal fungi (AMF) and plant growth promoting rhizobacteria (PGPR). In this study, the impact of a selected AMF complex and a selected PGPR species on the growth of tomato (Lycopersicum esculentum Mill.) under induced water stress was evaluated. Methods: Three different inoculation treatments were applied to tomato seedlings (a complex of AMF composed mainly of Glomus genus a Bacillus sp. PGPR treatment and a combination of both) and three different water levels (75%, 50% and 25% of field capacity). Result: A significant damaging impact of drought on tomato growth parameters and root mycorrhizal colonization, although the presence of microbes stimulated tomato plants growth and decreased the impact ofdrought stress. Indeed inoculated plants presented greater heights, fresh and dry weights, leaves number and area; greater water status; and greater proteins, sugars and chlorophylls contents either with the AMF complex or the Bacillus sp. in normal and drought stress conditions compared to the non-inoculated plants. However dual inoculation recorded the highest values under all water levels treatments.

Soil compaction in a new light: Know the cost of doing nothing – A cotton case study

Increased size of farm machinery has improved farm efficiency but at the risk of soil compaction. Here we present a novel approach investigating the effect of compaction due to in-field traffic by continuously monitoring crop canopy temperature and soil profile moisture and measuring crop yield in individual crop rows to determine the economic impact on cotton farming systems. Traffic by a tractor weighing 19.2 Mg either side of the plant row reduced lint yield by 27 % due to lower crop height, leaf area, biomass and fruit number. Elevated canopy temperature (Tc) in the compacted plots resulted in 30 % higher stress time (i.e. cumulative time when Tc is higher than the optimum Tc for cotton growth) compared with the non-compacted plots. Higher stress time in compacted plots was correlated with a 72 % and 27 % reduction in crop water use (estimated from change in soil water) at 0.3−0.5 m and 0.5 – 0.7 m depths, respectively. Water recharge in the soil profile from irrigation and rainfall was reduced by 16 % due to compaction with the highest reduction being 86 % at 0.3 – 0.5 m depth. These results demonstrate that compaction likely reduced root access to water below 0.3 m inducing water stress resulting in yield reduction. Tractors used for farm operations only compact one side of the bed, however, both sides are compacted in the absence of permanent wheel tracks. By comparison a dual tyre round module cotton picker weighing ∼32 Mg compacts 67 % of the rows on both sides and 33 % on one side suggesting greater economic loss in the following season compared to that estimated from the current study. Reductions in soil water recharge following irrigation and rainfall events due to compaction will further decrease farm efficiency and profitability. To our knowledge this is the first study related to soil compaction in any crop to show the direct relationship between yield, plant stress time and soil water dynamics at specific depths in profile. It is suggested that short term agronomic decisions (eg irrigation scheduling) need to be considered differently where compaction has been identified as limiting productivity. We recommend case studies be conducted to monitor the effect of compaction on commercial farm productivity and to demonstrate the cost of compaction across agricultural industries to drive practice change. Demonstrating the potential economic consequences of soil compaction by the integrated approach used in this study may encourage practice change to minimize compaction on farms.

Screening of Pearl Millet Genotypes Suitable for Drought Tolerance at Early Seedling Stage

Background: Pearl millet [Pennisetum glaucum (L.) Br.] is the most widely grown staple food of majority of poor and small land holders in Asia and Africa. It is also consumed as feed and fodder for livestock. It is the sixth most important cereal crop in the world next to maize, rice wheat, barley and sorghum. The temperature is one of the key climatic factors and has profound effect on the growth and development of the pearl millet. It can only be managed through developing hybrid varieties which can tolerate high temperature during germination and early seedling stages.The present study aimed to identify drought tolerant genotypes of pearl millet at seedling stage. Methods: This experiment was carried out at Mandor during kharif 2018 with five selected pearl millet advanced hybrids MH 2192, MH 2224, MH 2228, MH 2354 and MH 2359 along with three checks RHB 177, MPMH 17 and 86M86 which were tested under polyethylene glycol (PEG) (5% and 10%) induced osmotic stress. Various physiological parameters were recorded 15 days after sowing and statistical analysis made using Windostat software. Result: The results revealed that shoot length, seedling dry weight, relative water content, membrane stability index and chlorophyll content decreased significantly with PEG induced water stress in all the hybrids while root length and catalase activity increased significantly under water stress. Among 5 hybrids, two hybrids viz. MH 2359 and MH 2354 performed better and found to be superior under PEG induced water stress. Thus, various drought tolerance indices may further be studied for these two hybrids and can be used in development of drought tolerant genotypes which may prove helpful for crop improvement programs of pearl millet.

Effects of Induced Water Stress at the Flowering Stage of Bambara Groundnut (<i>Vigna subterranea</i> L. Verdc) on Its Yield

Bambara groundnut (<i>Vigna subterranea </i>L. Verdc), a neglected and underutilized legume is one of the main source of plant protein for poor families in tropical Africa, and is capable of contributing to increasing food production in Africa. This present study aimed to see how bambara groundnut respond to induced water stress during the flowering stage. The research was carried out at the Teaching and Research Farm of The Federal College of Agriculture, Akure (FECA), Ondo State, south west zone in Nigeria. The experiment was a split-plot experiment laid out in a Completely Randomized Design (CRD) with three replications during the late planting season of 2020. Data were collected on Plant height, Number of branches, Number of Leaves, Terminal Leaf Length, Terminal Leaf Width (cm), Biomass, Wet Pod Weight/Plant, Dry Pod Weight/Plant, Pod Length, Pod Width, Number of Pods/Plant, Seed Length, Seed Width, Number of Seeds/Plant, and Seed Weight/Plant. Result showed that among the growth parameters evaluated, Number of leaves and branches were significantly influenced by the various induced stress conditions and the control plot recorded the most significant difference. Among the accessions; accession B₈ recorded significantly higher number of leaves across the weeks, while accession B₁ recorded significantly higher number of branches in week 4 and 12 whereas, B₆ recorded against week 8. The interaction C*B₈ recorded significantly higher number of leaves and branches at week 4, whereas at week 8 and 12, the interaction DRT*B₁ recorded significantly higher number of leaves for both weeks, while C*B₆ with at week 8 and at week 12 recorded significantly higher number of branches. For the yield, the result obtained showed that the control significantly (p ≤ 0.05) improved dry seed weight and other yield components (number of pods/plant, number of seeds/plant) of bambara groundnut. The bambara groundnut accessions exhibited differential yield potential. The highest wet and dry seed weight/plant was obtained in the B₄ followed by the B₇ and lowest is the B₁₀. The B₄ out-yielded the other accessions, indicating its high adaptability and suitability to the various induced stress conditions at the flowering stage of the bambara plant.

Study of drought stress using PEG-6000 on germination stage of sesame germplasm (Sesamum indicum L.) under laboratory conditions

Sesame is a drought tolerant oilseed crop, but it is sensitive to drought at germination stage. This study was conducted to determine the effect of drought stress on germination of Eight hundred twenty nine sesame germplasm. The experiment was conducted in the laboratory of the Project Co-ordinating Unit, All India Coordinated Research Project on Sesame and Niger (Indian Council of Agricultural Research), JNKVV Campus, Jabalpur (MP). Eight hundred twenty nine sesame germplasm and two levels of drought (0.0 (control) and -4.9 bar) were the treatment tested in the experiment. Study of boxplot analysis results which is used to visually summarize and compare groups of data. On considering the values of germination percent were found maximum in SI-1116, followed by IS-158-3-84, PCU-130, PCU134, NIC-17257, NIC-8399-I, S-0534, RJS-194, JLT-8, IS-130, NIC-17868, NIC-7795-A, ES-10-A and EC-138836-A at -4.9 bar and being identified as the most tolerant germplasm among those tested in this experiment. Distinction of significant difference in germination of germplasm in induced water stress suggested that this parameter could be used as criteria in to screen germplasm to identify those most drought stress at germination stage.

Capparis Decidua Edgew (Forssk.) Stem Extract Alleviates the Water Stress Perturbations in Wheat (Triticum Aestivum L.) at Early Growth Stage

Water shortage is one of the major limiting factors of crop productivity worldwide. This study was planned to explore the impact of Capparis decidua stem extract on wheat varieties (FSD-2008, 12066 and 13348) under water stress condition. Water deficit condition negatively impacted the seedling germination, growth, photosynthetic pigments and ions uptake capacity. Water limited condition significantly (p≤0.05) increased time to attain 50% germination, lipid peroxidation, H2O2 and enhanced the antioxidant mechanism to overcome the oxidative stress. Different concentrations of C. decidua extract i.e. Not Soaking (NS), 10%, 20%, 30% and 40% were used for seed priming. It improved the negative effects of water stress and amended plant germination and growth by enhancing photosynthesis and reactive oxygen species (ROS) scavenging mechanism. The 20% and 30% C. decidua stem extract remained effective in mitigating the induced water stress effects in the tested cultivars. It was found that C. decidua stem extract significantly (p≤0.05) improved germination, growth Mg+2 and Fe+2 uptake in the wheat varieties under study. It is concluded that C. decidua phytoextract is an influential agent to ameliorate water stress effects in wheat at early growth stage.