Peanut Research Articles

Exogenous melatonin improves peanut field productivity and quality at reduced nitrogen application

ContextNitrogen (N) plays integral roles in plant growth and yield. Finding ways to increase plant yield with reduced N usage will promote both agricultural and environmental sustainability. Melatonin acts as a multifunctional regulatory molecule in numerous metabolic processes crucial for plant growth and development as well as response to environmental stresses. The effects of melatonin on the material accumulation and transport, source-sink dynamics, as well as its association with yield and quality formation of peanut (Arachis hypogaea L.) remain unclear, especially at different N levels. ObjectivesWe aim to investigate the response mechanism of melatonin in peanut plants subjected to reduced N application, in order to confirm the hypothesis that melatonin regulates carbon and N accumulation and transport, and coordinates source-sink relationships to increase production and improve quality. MethodsThis study examined the effects of two seed dressing treatments (with or without 0.5μM MT) and three N fertilizer levels (90, 135, and 180kg/ha) using a randomized complete block design with split plots and three biological replications over 2021 and 2022. The evaluation focused on photosynthetic physiology, enzyme activities related to carbon and N metabolism, accumulation and transport of dry matter and N, yield, and quality, while exploring the relationships among these variables. ResultsMelatonin-treated plants had more stable carbon and N metabolism than the untreated ones. This stability was linked to improved photosynthesis, sucrose production, and N assimilation, especially at the reduced N levels (90 and 135kg/ha). Across three N levels and two years of field tests, MT increased peanut dry matter by 23.49% from 455.63g/m2 to 562.66g/m2, enhanced the accumulation and mobilization of dry matter and N to grains by increasing peanut grain mass by 22.41-29.07% at different N levels. This process appears to subsequently elevate the effective pod rate, leading to an average increase in pod yield, fat and protein content by 12.63%, 7.95%, and 10.33%, respectively, over a two-year period and across three N application levels. ConclusionsPlants subjected to melatonin treatment exhibited a coordinated source-sink relationship, which is manifested in high photosynthetic capacity and a high proportion of assimilates transported to pods, thus promoting effective proportions and pod fullness to improve peanut yield and quality under reduced N application. SignificanceOur research provided insights into the response mechanism of melatonin on peanut carbon and N metabolism across various N treatments, contributing to a deeper understanding of how melatonin enhances crop yield and quality.

Cement Board Using Discarded Peanut Shell (Arachis Hypogaea)

This study investigates the use of powdered peanut shells as a sustainable alternative in cement board production. With the growing emphasis on eco-friendly construction materials, exploring alternative resources is essential. Cement boards were fabricated incorporating powdered peanut shells at varying percentages (5%, 10%, and 15% by weight) relative to the total weight of the cement mixture. The preparation involved calculating the sample volume, adjusting the mixture weight to account for the peanut shells, and setting the water-cement ratio to 0.46. The process included grinding the peanut shells, measuring all components, and thoroughly mixing them before molding. The mixtures were cured in a controlled environment to promote proper setting. The physical, mechanical, and thermal properties of the resulting boards were evaluated according to ASTM standards and analyzed using SPSS. Notably, the 5% mix achieved the highest density (1.60 g/cm³) and demonstrated excellent heat resistance, while the 15% mix exhibited the greatest thickness (1.24 cm) and lowest water absorption (10.99%). The 10% mix resulted in the highest compressive (11.28 MN/m²) and tensile strengths (0.24 N/cm²). The findings suggest that incorporating powdered peanut shells significantly improves the properties of cement boards, presenting a viable and sustainable construction option. Future studies should focus on optimizing these mixtures and assessing their long-term durability.

Molecular characterization of Pleiotropic Drug Resistance (PDR) genes involved in tolerance of cadmium in peanut (Arachis hypogaea L.).

Peanut (Arachis hypogaea L.) is one of the most important oil crops worldwide. Cadmium (Cd), a heavy metal that is nonessential and toxic, has the potential to significantly impacted the quality and safety of peanut. Despite the known importance of Pleiotropic Drug Resistance (PDR) genes in heavy metal accumulation and transport in plants, there is a lack of comprehensive research on the systematic identification and functional characterization of AhPDRs in peanut. In this study, a total of 38 AhPDR genes were discovered within the peanut genome. Among these, AhPDR24, AhPDR30, and AhPDR33 displayed notable variations in expression levels in response to Cd stress. Particularly noteworthy was the observation that AhPDR33, localized in the plasma membrane, exhibited a significant increase in expression (approximately 3.8-fold) and heightened promoter activity (approximately 4.1-fold) following exposure to Cd (75 μM CdCl2). Furthermore, the study found that the overexpression of AhPDR33 in Arabidopsis resulted in increased root elongation and decreased Cd accumulation (approximately 0.42-fold) compared to wild-type plants. This suggests that AhPDR33 may have a beneficial role in facilitating Cd efflux and tolerance in plants. Additionally, transient silencing of AhPDR33 in peanut demonstrated its positive regulation of Cd tolerance through the promotion of reactive oxygen species (ROS) scavenging and membrane permeability reduction. These findings contribute to the understanding of the molecular mechanisms involved in AhPDR33-mediated Cd tolerance and detoxification in peanut. Furthermore, this study provides comprehensive information to understand the AhPDR gene family, its features, and its expression, which will hold a promising utility as an excellent candidate in the genetic improvement of peanut Cd stress tolerance.

Modulatory responses of physiological and biochemical status are related to drought tolerance levels in peanut cultivars.

Peanut (Arachis hypogaea L.) is the fourth most cultivated oilseed in the world, but its cultivation is subject to fluctuations in water demand. Current studies of tolerance between cultivars and physiological mechanisms involved in plant recovery after drought are insufficient for selection of tolerant cultivars. We evaluated tolerance of different peanut cultivars to water deficit and subsequent rehydration, based on physiological and biochemical status. Gas exchange, photosynthetic pigments, Fv/Fm, MDA, H2O2 and antioxidant enzyme activity were analysed. Drought stress and rehydration triggered distinct changes in pigments, Fv/Fm, gas exchange, and H2O2 across genotypes, with increased MDA in all cultivars under stress. Based on multivariate analysis, 'IAC Sempre Verde' was identified as most drought sensitive, while 'IAC OL3', 'IAC 503', and 'IAC OL6' exhibited variations in physiological responses and antioxidant activity correlated to their respective tolerance levels. Notably, 'IAC OL3' had higher WUE and enhanced enzymatic defence and was classified as the most drought tolerant in this context. The above findings suggest that antioxidant metabolism is a important factor for plant recovery post-rehydration. Our study provides insights into antioxidant and physiological responses of peanut cultivars, which can support breeding programs for selection of drought-tolerant genotypes. Future field studies should be conducted for a better understanding of tolerance of these cultivars, particularly through correlation of these data with crop yield impact.

Integrative Analysis of Metabolome and Transcriptome Reveals Molecular Mechanisms Regulating Oil and Protein Content in Peanut (Arachis hypogaea L).

Peanut (Arachis hypogaea L.) is an important source of edible vegetable oils and plant proteins globally. However, the complex mechanisms regulating the oil and protein contents of peanut seeds remain unclear. Here, comparative broad-target metabolomics and quantitative lipidomics, together with transcriptome analysis, of peanut seeds at four developmental stages from the high-oil content variety "YH15" and high-protein content variety "KB008" were performed to search for oil and protein content control genes. A total of 984 differential metabolites, including 128 amino acids and derivatives and 310 differentially accumulated lipids, were identified between "YH15" and "KB008" in four seed developmental stages. The weighted gene coexpression network analysis and module-trait relationship analysis revealed that MEbrown, MEyellow, and MEturquoise modules were key contributors to the quality discrepancies observed between "YH15" and "KB008." Crucial genes potentially regulating the differences in oil and protein contents between "YH15" and "KB008" were identified within the aforementioned three modules, including genes involved in amino acid synthesis and degradation, nitrogen allocation, triglyceride synthesis and degradation, and fatty acid synthesis and degradation, as well as transcription factors. Overall, this study provides valuable insights into the molecular regulation of oil and protein contents in peanut seeds and may help cultivate specialized peanut varieties with enhanced nutritional and economic values.

Genome-wide analysis of the PLATZ gene family provides insights into the genome evolution of cultivated peanut (Arachis hypogaea, Leguminosae)

Genome-wide analysis of the PLATZ gene family provides insights into the genome evolution of cultivated peanut (Arachis hypogaea, Leguminosae)

Synthesis, characterization and photo catalytic activity of silver nano particle derived from Arachis hypogaea L. seed peel extracts

Abstract The study focuses on the green synthesis of silver nanoparticles (AgNPs) using Arachis hypogaea L. seed peel extract (AHSPE) and evaluates their photocatalytic activity against Rhodamine B and Congo Red dyes. The synthesis involved reducing aqueous silver metal ions with AHSPE, characterized by various techniques including UV–visible spectroscopy, X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), and FT-Raman spectroscopy. UV–visible spectroscopy indicated characteristic absorption peaks at 428 and 439 nm, confirming the formation of AgNPs. XRD analysis revealed an average particle size of 4.77–5.6 nm. FT-IR spectra identified biomolecules such as amines, peptides, amides, lactones, and polyphenols in the extract, acting as reducing and capping agents, thereby stabilizing the AgNPs. SEM analysis showed pristine silver nanoparticles with diameters ranging from 1 to 10 µm. The biosynthesized AgNPs demonstrated strong photocatalytic activity in degrading Rhodamine B and Congo Red dyes. This method did not use any synthetic reagents, making it an environmentally safe and cost-effective alternative for synthesizing silver nanoparticles. The process aligns with green chemistry principles, offering potential applications in photocatalysis and environmental cleanup. The study underscores the importance of biosynthesized nanoparticles due to their unique biological properties and the role of plant secondary metabolites in facilitating green synthesis.

Influence of tillage and rotation sequence on corn response and planting pattern

Plain Language SummaryCorn (Zea mays L.), cotton (Gossypium hirsutum L.), and peanut (Arachis hypogaea L.) are traditional crops grown in the southeast region of the United States. Row crop producers have adopted many strategies to reduce the presence of disease and parasitic nematodes among peanut. One management strategy that has not been considered is the potential use of twin‐row planting patterns compared to single‐row cropping systems under various tillage practices. The objective of this study is to determine if corn yield differs when comparing twin‐row and single‐row planting patterns when planted in various rotation sequences following corn, cotton, and peanut in continuous strip tillage or conventional tillage. Results indicated that corn yield increased as the length of rotation increased relative to peanut. Furthermore, the increase in the planting of cotton within the rotation also increased corn yield. The use of strip tillage increased corn yield compared to conventional. No significant yield increase was seen when comparing twin‐row to single‐row.

Genome-Wide Identification of Basic Helix–Loop–Helix (bHLH) Family in Peanut: Potential Regulatory Roles in Iron Homeostasis

The basic helix–loop–helix (bHLH) superfamily is the second-largest transcription factor family that participates in a wide range of biological processes in plants, including iron homeostasis. Although the family has been studied in several plant species, a comprehensive investigation is still needed for peanut (Arachis hypogaea). Here, a genome-wide analysis identified 373 AhbHLH genes in peanut, which were divided into 14 groups or subfamilies according to phylogenetic analysis. Clustered members generally share similar gene/protein structures, supporting the evolutionary relationships among AhbHLH proteins. Most AhbHLHs experienced whole-genome or segmental duplication. The majority of AhbHLH proteins had a typical bHLH domain, while several phylogenetic groups, including Group VI, X, XIII, and XIV, had the HLH domain. The expression of several AhbHLH genes, including AhbHLH001.3, AhbHLH029.1/.2, AhbHLH047.1/.2, AhbHLH115.1/.2, AhbHLH097.1/.2, AhbHLH109.4, and AhbHLH135.1, was induced by Fe deficiency for both cultivars, or at least in Silihong, suggesting an important role in the Fe deficiency response in peanut. Nine genes (AhbHLH001.3, AhbHLH029.1/.2, AhbHLH047.1/.2, AhbHLH097.1/.2, and AhbHLH115.1/.2) were specifically induced by Fe deficiency in Silihong, and their expression was higher in Silihong than that in Fenghua 1. These genes might be responsible for higher tolerance to Fe deficiency in Silihong. Our findings provide comprehensive information for further elucidating the regulatory mechanism of Fe homeostasis in peanut.

Response to oxalic acid: an important supplement screening against stem rot resistance in groundnut (Arachis hypogaea L.)

BackgroundStem rot, caused by the soil-borne pathogen Sclerotium rolfsii, pose a serious challenge in the groundnut (Arachis hypogaea L) cultivation. Although this disease is widespread globally but had most adverse impact in groundnut growing regions of United States, India, and Australia. The pathogen primarily targets the crown region of the plant, resulting in systemic collapse and potentially leading to yield losses up to 80%. Effective genetic control measures are essential to mitigate the impact of this disease on groundnut production. Realizing the time and resource-consuming complex field-based phenotyping, the availability of easy and repeatable phenotyping methods may fasten the process of donor and gene discovery efforts.ResultsMulti-season phenotyping was performed for stem rot on 184 minicore germplasm accessions, including checks, under two conditions: sick field screening and response to oxalic acid assay. This study demonstrated medium to high heritability (52–63% broad-sense heritability) and significant environmental influence (36%). The response to the oxalic acid assay showed a high proportion of similarity (approximately 80%) with the percent mortality observed in the sick field indicating an easy way of performing precise phenotyping. Notably, seven genotypes—ICG163, ICG721, ICG10479, ICG875, ICG11457, ICG111, and ICG2857—exhibited stable resistance, with less than 30% mortality against stem rot disease. Among these, ICG163, ICG875, and ICG111 displayed low mortality and consistent stability across multiple seasons in both the sick field and controlled conditions of the oxalic acid assay.ConclusionsThe oxalic acid assay developed in this study effectively complements field phenotyping, as a reliable method for assessing stem rot resistance. Seven resistant genotypes identified through this assay can be utilized for the introgression of stem rot resistance into elite genotypes. Given the significant influence of the environment on stem rot resistance, it is essential to implement multi-season phenotyping to obtain precise results. Furthermore, the response to oxalic acid serves as a valuable supplement to traditional field phenotyping, since maintaining uniform disease pressure during field screenings is often challenging.

How does parental diet affect offspring locomotor capacity in the bean bug, Riptortus pedestris?

AbstractParental environments have profound consequences for offspring fitness through transgenerational transmission of resources and epigenetic factors. Locomotor activity is a functional trait of considerable ecological importance, as it determines the ability of animals to find food and mates and to disperse to more favourable environments. Although there have been studies demonstrating that animals can plastically increase their locomotor capacity in response to nutritionally stressful environments, it remains largely unexplored whether and how parental diet can adjust offspring locomotor capacity and its related traits. In this study, we tested the hypothesis that the parental intake of a nutritionally suboptimal diet would induce hyperactivity in the offspring and that this transgenerational effect could lead to improved offspring performance in an insect herbivore, the bean bug (Riptortus pedestris Fabricius) (Hemiptera: Alydidae). We compared the locomotor activity, metabolic phenotype and performance traits of two groups of R. pedestris nymphs born to parents raised on soybeans [Glycine max (L.) Merr, Fabaceae; standard diet] or peanuts (Arachis hypogaea L., Fabaceae; high‐fat diet). Despite being smaller at birth, the offspring of peanut‐fed parents moved faster and more frequently than those of soybean‐fed parents during their early development. The newly hatched offspring born to peanut‐fed parents had higher relative energy reserves in somatic tissues than those born to soybean‐fed parents, indicating that differential parental provisioning could underpin this parental effect on offspring locomotor activity. Possibly through increased foraging activity, the hyperactive offspring of peanut‐fed parents grew faster into heavier adults than the offspring of soybean‐fed parents, implying that parentally induced increase in offspring locomotor activity is adaptive. This study provides experimental evidence for diet‐mediated transgenerational plasticity of locomotor activity in invertebrates and sheds novel insights into the role of parental diet history in shaping offspring phenotype.

Transcriptome-Based Spatiotemporal Analysis of Drought Response Mechanisms in Two Distinct Peanut Cultivars

Drought tolerance varies among different peanut (Arachis hypogaea L.) cultivars. Here, drought responses of two cultivars, Huayu 22 (HY22) with drought tolerance and Fuhua 18 (FH18) with drought sensitivity, were compared at the morphological, physiological, biochemical, photosynthetic, and transcriptional levels. Drought stress caused wilting and curling of leaves, bending of stems, and water loss in both cultivars. There was an increase in malondialdehyde (MDA) content under prolonged drought stress, more so in FH18. But the levels of reactive oxygen species (H2O2) and lipid peroxidation were low in HY22. The activities of superoxide dismutase (SOD), peroxidase (POD), and glutathione reductase (GR) were considerably elevated, corresponding with rapid increases in the accumulation of soluble proteins, soluble sugars, and proline. Transcriptional sequencing showed gene expression varied seriously in HY22, which was upregulated in both stems of two cultivars, though downregulation was less pronounced in HY22. KEGG pathway analysis revealed significant enrichment in four leaf and six stem pathways. Additionally, core genes relating to photosynthesis, carbon fixation, proline synthesis, and sucrose and starch synthesis pathways were identified by correlation analysis. Those gene expressions were variously upregulated in stems of two cultivars, especially in HY22, giving a novel view of the shoot as a whole participating in stress response.

Isolation, identification, characterization and in vitro assay of saline tolerant endophytes against groundnut root rot caused by Rhizoctonia bataticola (Taub.) Butler

Groundnut, known as Arachis hypogaea L., is India's significant oil seed crop. Dry root rot, caused by Rhizoctonia bataticola, poses a substantial challenge to cultivating groundnuts. During the roving survey, 60.50% dry root rot disease incidence was recorded in Namakkal district, Tamil Nadu. This study aims to acquire salt-tolerant endophytic bacteria residing in groundnuts with significant antagonistic activity against R. bataticola. A total of 27 bacterial strains were isolated from groundnuts. Among these strains, RMV 3 and RMV 2 are the most effective isolates, exhibiting 60.1% and 50% inhibition zones, respectively. The effective isolates were characterized through morphological, biochemical and phytostimulation activities and 16S rDNA sequencing. Among the isolates, RMV 3 and RMV 2 showed positive results for siderophore, indole acetic acid (IAA) and cellulase test. The strain RMV 3 was identified as Bacillus subtilis through 16S rDNA sequencing. GC-MS analysis identified twenty bioactive compounds produced by B. subtilis RMV 3, such as pyrrolo [12-a] pyrazine-14-dione hexahydro-3 (2-methylpropyl) and hexadecanoic acid methyl ester. The crude metabolite assay demonstrated a 96.6% inhibition of R. bataticola by RMV 3. This study demonstrated that Bacillus subtilis RMV 3, which exhibits a robust antagonistic effect on R. bataticola, can potentially be an effective biocontrol agent for groundnut dry root rot.

Groundnut (Arachis hypogaea L.) Response to Nitrogen Fertilizer and Earthing Up Practices in the Tigray Region of Ethiopia

To increase groundnut yields, integrated agronomic techniques must be implemented. The current study focuses on using starter nitrogen fertilizer in conjunction with earthing up for groundnut cultivation. Three replications and a factorial combination were used in the complete randomized block design of the experiment. Two types of earthing up (no earthing up and earthing up) and four levels of nitrogen fertilizer (0, 15, 30, and 45 kg ha-1) were used in the treatment combinations. For each of the Hamedo 1 and Hamedo 2 experimental sites, two undisturbed and two disturbed composite soil samples were collected at a depth of 20 cm before sowing. The data analysis showed that neither the combination application of N fertilizer and earthing up nor the individual independent applications of N fertilizer and earthing up had a significant effect on groundnut flowering and maturity. Groundnut plant height, number of branches per plant, number of pods per plant, number of seeds per plant, seed weight per plant, and haulm yields were not significantly affected by earthing up alone or by the co-application of nitrogen fertilizer and earthing up. On the other hand, the exclusive use of nitrogen fertilizer significantly affected groundnut plant height, the number of branches per plant, the number of pods per plant, the number of seeds per plant, seed weight per plant, and haulm yield. Applying 45 kg ha-1 of nitrogen fertilizer to the Hamedo 1 and Hamedo 2 trial sites enhanced the haulm yield by 70.53% and 78.76%, respectively, compared to the unfertilized plots. Individual applications of nitrogen fertilizer, earthing up, or a combination of both had a significant effect on groundnut pod and kernel yields. In comparison to plots that received a combined application of 45 kg ha-1 of nitrogen fertilizer and earthing up, the Hamedo 1 and Hamedo 2 trial sites exhibited increases in pod yields of 57.73% and 55.97%, respectively, when earthing up was combined with 15 kg ha-1 of nitrogen fertilizer. In the same way, applying 15 kg ha-1 of nitrogen fertilizer to the earthing-up soil in the Hamedo 1 and Hamedo 2 experimental sites boosted the kernel yields by 70.05% and 75.43%, respectively, in comparison to soil earthing-up plots that received 45 kg ha-1 nitrogen. The findings of the economic and agronomic analyses showed that applying nitrogen fertilizer and earthing up together greatly increases groundnut yields and revenues. Therefore, to increase groundnut yields and receive more financial advantages, farmers can consider the combined application of 15 kg ha-1 of nitrogen fertilizer and earthing-up.

Evaluation of Groundnut (Arachis hypogaea) Genetic Variability for High-Temperature Tolerance in Controlled and Field Conditions

Evaluation of Groundnut (Arachis hypogaea) Genetic Variability for High-Temperature Tolerance in Controlled and Field Conditions

Impact of foliar nutrition on growth, yield attributes, yield, quality parameters and economics of groundnut [Arachis hypogaea (L.)] under rainfed condition

Impact of foliar nutrition on growth, yield attributes, yield, quality parameters and economics of groundnut [Arachis hypogaea (L.)] under rainfed condition

Physicochemical, techno-functional, biochemical and structural characterization of a protein isolate from groundnut (Arachis hypogaea L.) paste treated with high-intensity ultrasound

The objective of this research was to evaluate the effect of ultrasound (HISound) (200, 400 and 600 W; 15–30 min) on the physicochemical, biochemical and structural techno-functional properties of a groundnut paste protein isolate (GPPI). HISound increased the contents of free sulfhydryls (552.22 %), total sulfhydryls (124.68 %) and α-helix (389.75 %), as well as molecular flexibility (50.91 %), hydrophobic surface (38.99 %), and particle size (171.45 %) of GPPI, which improved protein solubility by 8.05 %, oil holding capacity by 73.54 %, emulsifying stability index by 226.25 % and foaming capacity by 216.00 %, compared with non-sonicated GPPI. Also, the microstructure analysis revealed smooth structures, with molecular weights in the range of 13.88–67.07 kDa. Pearson analysis determined some highly significant correlations (r ≥ 0.90, p < 0.01) between some GPPI protein properties. The improvement of GPPI properties by HISound could contribute to its use as an ingredient for human consumption.

Determining the type of gene action(s) involved in the genetic control of drought-tolerance and yield-associated traits of groundnut (Arachis hypogaea L.) using generation mean and variance analysis of parental, F1 and the segregating populations (backcrosses and F2)

Determining the type of gene action(s) involved in the genetic control of drought-tolerance and yield-associated traits of groundnut (Arachis hypogaea L.) using generation mean and variance analysis of parental, F1 and the segregating populations (backcrosses and F2)

Response of groundnut (Arachis hypogaea L.) to foliar nutrition of urea phosphate

Response of groundnut (Arachis hypogaea L.) to foliar nutrition of urea phosphate

Assessment of Genetic Variability in Groundnut (Arachis hypogaea L.)

The present study was carried out with thirty advanced breeding lines of groundnut for estimation of genetic variability, heritability and genetic advance. Analysis of variance revealed highly significant differences among genotypes for all the studied characters indicating that there is substantial variability among the genotypes for these traits. High estimates of GCV and PCV was observed for pod yield per plant, kernel yield per plant, dry haulm yield per plant and number of mature pods per plant. High heritability coupled with high genetic advance as per cent of mean were recorded for number of mature pods per plant, pod yield per plant, kernel yield per plant, dry haulm yield per plant, number of immature pods per plant, plant height, harvest index and hundred kernel weight indicating the preponderance of additive gene action in expression of these traits and hence simple phenotypic selection would be effective for improvement of these characters.