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Peanut (Arachis hypogaea L.) holds significant commercial and dietary importance as a major source of edible oil and protein in Turkey. Stem, collar or root rot, caused by several fungal disease agent, are serious soil-borne diseases of peanut. Accurate and precise identification of the disease agent provides fundamental and precise information for integrated plant management. During the period from June to September 2021, symptoms consistent with collar rot disease, including dark-brown stem rot, chlorotic leaves, wilting, and eventual whole plant death, were observed on peanut plants cultivated in the different districts of Osmaniye Province of Turkey. The disease incidence ranged from 8.0 to 45.0% in the inspected fields with an average of 3.4% overall. Twenty-four single-spore representative isolates were obtained from surface-disinfected symptomatic tissues. Morphological characteristics of fungal mycelium, conidial and pycnidial structures on potato sucrose agar (PSA) and water agar (WA) closely resembled those described for Lasiodiplodia spp. All isolates caused typical collar rot symptoms upon artificial inoculation of peanut seedlings. Morphological identification of Lasiodiplodia spp. isolates was corroborated by MALDI-TOF and molecular analyses utilizing sequences from the internal transcribed spacer (ITS), β-tubulin 2 (tub2) and translation elongation factor-1 alpha (TEF1-α) loci. Phylogenetic analysis confirmed that the representative fungal isolates (MKUBK-B1 and MKUBK-K22) belong to Lasiodiplodia pseudotheobromae. To the best of our knowledge, this is the first report of L. pseudotheobromae infecting peanut plants in Turkey. This work is expected to contribute to previously limited knowledge regarding the host range, incidence and prevalence of L. pseudotheobromae as a soilborne pathogen of peanuts. Due to the potential destructiveness and broad host range of this pathogen, it is essential to develop new strategies to establish more reliable, environmentally sustainable, and cost-effective management approaches for this disease. [ABSTRACT FROM AUTHOR]

This study aimed to assess the growth and development of 42 kDa chitinase-transgenic peanut lines in the T1 progeny and their phytopathogenic fungus resistance. Line S1A-12 contains the syncodChi42-1 gene, line S2A-11 contains the syncodChi42-2 gene, and lines WTA-3 and WTA-5 contain the Chi42 gene. The Chi42 gene is derived from Trichoderma asperellum SH16. SyncodChi42-1 and syncodChi42-2 are sequences of the Chi42 gene optimized for codon usage in plant expression. The study results showed that all four transgenic peanut lines maintained fungal resistance in T1 progeny. However, only three lines, S1A-12, WTA-3, and WTA-5, were segregated in the Mendelian ratio (3:1). T1 transgenic peanut lines grew more vigorously and produced higher numbers of mature pods, 100-pod weight, and 100-seed weight than the non-transgenic control. In which the S2A-11 line exhibited the strongest growth and development ability. The four transgenic lines had a higher protein content than the control, but their lipid and reducing sugar contents were similar. These findings suggest that transgenic peanuts containing one of two optimized chitinase genes may be promising candidates for the production of peanut cultivars resistant to phytopathogenic fungi. [ABSTRACT FROM AUTHOR]

In the present study, the thermal conversion of Arachis hypogaea (groundnut) husk into biochar and its subsequent application in the adsorptive removal of Cr(VI) from an aqueous solution has been studied. The SEM–EDX and LIBS analyses showed that the adsorbent material incorporates both magnesium (Mg) and chromium (Cr) on its surface. The FTIR spectra revealed the involvement of several functional groups in the Cr(VI) adsorption, including –OH, Mg–O–Mg, –CH, –NH, and –COO. Specific surface area (SSA) is determined using BET (Brunauer–Emmett–Teller) analysis and the SSA of adsorbent material was 35.83 m2 g−1. Data from batch adsorption experiments demonstrated that magnesium-supported biochar increased the binding capacity of the adsorbent to the Cr(VI) ions. Adsorption experiment data at equilibrium conditions showed that the Langmuir model provided a best suited to the nMgO@GHBC than the Freundlich and Temkin models with a maximum adsorption capacity of 93.86 mg g−1. The kinetic-second-order model with the highest R2 value of 0.993 and the lowest values for root mean square error and chi-square (χ2) can reasonably explain the hexavalent chromium adsorption data. This study suggested that the mechanism of Cr(VI) adsorption onto both adsorbents might be chemisorption or ion exchange processes as adsorption data effectively fitted the PSO model. The outcomes of thermodynamic parameters like ΔG° indicated that Cr(VI) adsorption on pGHBC and nMgO@GHBC was spontaneous. Fixed-bed-column studies were conducted at different experimental conditions, such as inlet flow rate and bed height. The outcomes of the experimental data showed that the adsorption capacity of adsorbent for Cr(VI) adsorption in a fixed bed continuous flow was 50 mg g−1. The adsorbent was recycled ten times using NaOH, HNO3, H2SO4, and EDTA. The continuous adsorption and desorption of Cr ions for up to 10 cycles showed the reusability of spent biochar. [ABSTRACT FROM AUTHOR]

Insoluble phosphorous compounds solubilization by soil bacteria is of great relevance since it puts available the phosphorus to be used by plants. The production of organic acids is the main microbiological mechanism by which insoluble inorganic phosphorus compounds are solubilized. In Gram negative bacteria, gluconic acid is synthesized by the activity of the holoenzyme glucose dehydrogenase-pyrroloquinoline quinine named GDH-PQQ. The use of marker genes is a very useful tool to evaluate the persistence of the introduced bacteria and allow to follow-up the effect of biotic and abiotic factors on these beneficial microorganisms in the soil. In previous studies we detected the presence of the pqqE gene in a great percentage of both non-culturable and culturable native soil bacteria. The objective of this study was to analyze the phylogeny of the sequence of pqqE gene and its potential for the study of phosphate solubilizing bacteria from pure and mixed bacterial cultures and rhizospheric soil samples. For this, the presence of the pqqE gene in the genome of phosphate solubilizing bacteria that belong to several bacteria was determined by PCR. Also, this gene was analyzed from mixed bacterial cultures and rhizospheric soil associated to peanut plants inoculated or not with phosphate solubilizing bacteria. For this, degenerate primers designed from several bacterial genera and specific primers for the genus Pseudomonas spp., designed in this study, were used. DNA template used from simple or mixed bacterial cultures and from rhizospheric soil samples was obtained using two different DNA extraction techniques. Results indicated that pqqE gene amplification product was found in the genome of all Gram negative phosphate solubilizing bacteria analyzed. It was possible to detect this gene in the DNA obtained from mixed cultures where these bacteria grew in interaction with other microorganisms and in that obtained from rhizospheric soil samples inoculated or not with these bacteria. The phylogenetic analysis indicated that pqqE gene is a conserved gene within related genera. In conclusion, pqqE gene could be a potential marker for the study of phosphate solubilizing bacterial populations. [ABSTRACT FROM AUTHOR]

Peanut stem rot disease, caused by the necrotrophic soil-borne fungus Sclerotium rolfsii, has a significant negative impact on crop yields. Chemical fungicides can mitigate the loss incurred by fungus, however, their usage raises environmental and human health concern. Seaweeds extracts are getting importance as bio-stimulant for improving growth and disease resistance in different plants. In the present study, we investigated the potential of Sargassum tenerrimum extract (S-extract) in controlling stem rot disease in peanuts. The foliar application of S-extract was applied at vegetative and reproductive stages on peanut plants to study plant growth and reduction of S. rolfsii-induced disease. Plant height, number of branches and branch length increased in S-extract treated plants (S) as compared to S-extract + S. rolfsii treated plants (S + F). Similarly, the activity of anti-oxidative enzymes such as catalase (CAT), guaiacol peroxidase (GPOX), polyphenol oxidase (PPO), and superoxide dismutase (SOD) increased by application of S-extract. Pigments such as chlorophyll a, chlorophyll b, and carotenoids showed higher accumulation in S-extract treated plants. The increased membrane stability index and reduced electrolyte leakage in S and S + F plants, positively affected the health and biotic stress tolerance of the plants. S-extract reduced the reactive oxygen species (ROS) such as O2•− and H2O2. Total phenol, soluble sugars and total amino acid accumulation were higher in S and S + F plants compared to C and F at vegetative stage. The mitigation of disease can be attributed to the application of S-extract leading to the elevated activity of antioxidant enzymes and the accumulation of non-enzymatic antioxidants, osmolytes, and pigments. Therefore, S-extract represents an environmentally friendly resource that can be employed in sustainable agriculture practices to boost plant growth and enhance disease tolerance. [ABSTRACT FROM AUTHOR]

The ratio of oleic acid to linoleic acid (O/L) is crucial for determining the shelf life of peanut oil. In peanuts, the expression of the Fatty Acid Desaturase 2 (FAD2) enzyme, which converts oleic acid to linoleic acid, is regulated by two homeologous genes called AhFAD2A and AhFAD2B. It has been observed that the Indian peanut cultivar GG20 does not possess natural mutations in the AhFAD2B gene. We successfully introduced a construct called CRISPR_GG20_AhFAD2B into the de-embryonated cotyledon of the GG20 plant. The purpose of this construct was to utilize the CRISPR-Cas9 gene editing technology to modify the AhFAD2B gene. Genotyping analysis of the plants that were potentially transformed with the construct confirmed that the target-specific editing had occurred in the AhFAD2B gene. Subsequently, the edited GG20 plants were phenotypically evaluated to assess the fatty acid composition in the peanut kernels. The results showed a notable increase in the O/L ratio, which rose from 3.1 in the control to 7.3 in the edited GG20 plants. This implies that the gene editing technique successfully enhanced the oleic acid to linoleic acid ratio in the peanuts, potentially improving the shelf life of the resulting peanut oil. [ABSTRACT FROM AUTHOR]

The potential production and productivity of groundnuts are limited due to severe drought stress associated with climate change. The current study aimed to identify genomic regions and candidate genes associated with drought tolerance and component traits for gene introgression and to guide marker-assisted breeding of groundnut varieties. Ninety-nine genetically diverse groundnut genotypes were phenotyped under drought-stressed and non-stressed field conditions in 2018/19 and 2019/20, and using the LeasyScan platform under non-stressed conditions in 2019/20 at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT)/India. The samples were genotyped using 48 K single nucleotide polymorphisms (SNPs) markers at the University of Georgia/USA. Phenotypic data was collected on 17 agronomic traits and subjected to statistical analyses. The SNP data were computed, and population structure was inferred using a Bayesian clustering method in Structure version 2.3.4, while linkage disequilibrium was calculated using the GAPIT program in R software. Marker-trait associations were deduced using Tassel 5.2.86. Significant phenotypic variations were recorded for drought tolerance and the assessed agronomic traits. GWAS analysis using PCA+K and Q+K models identified significant SNPs associated with leaf area (1 SNP), leaf area Index (1 SNP), specific leaf area (1 SNP), leaf relative water content (43 SNPs), number of primary branches (1 SNP) and hundred seed weight (1 SNP). Forty-seven and one marker-trait associations were detected under drought-stressed and non-stressed conditions, respectively. The candidate genes and markers identified in the current study are useful for accelerated groundnut breeding targeting drought tolerance and market-preferred traits. [ABSTRACT FROM AUTHOR]

The effects of inhibitor concentration on the corrosion rate and inhibition efficiency of AISI 1020 steel in an acidic and alkaline environment were investigated by means of weight loss measurement at an interval of 7 days and 14 days. To carry out this investigation, the Arachis hypogaea hull was extracted and concentrated in various weight percentages. The inhibition efficiency increased with the increased concentrations of AISI 1020 steel that were immersed in acidic and alkaline solution in the absence and presence of varying inhibitor concentrations of Arachis hypogaea hull extracts. The corrosion behavior, including the corrosion rate, is meticulously characterized through the corrosion rate analysis. The results showed that there is an increase in inhibition efficiency with an increase in inhibitor concentration and that there is a decrease in inhibition efficiency with an increase in immersion time. The organic inhibitor (Arachis hypogaea hull) produced the best inhibition efficiency of 96.4% at a 30% concentration. From the result obtained, Arachis hypogaea hull extracts revealed that it is best suited for inhibition of corrosion of mild steel in both acidic and alkaline environments. The goal of this research paper is to develop a comprehensive understanding of the corrosion inhibition and adsorption mechanisms associated with the implementation of the Arachis hypogaea hull as a natural corrosion inhibitor. [ABSTRACT FROM AUTHOR]

The quantity and quality of spray deposition are fundamental for improving pesticide performance in plant pests. This study evaluated how spray droplet size (1) and spray nozzle type (2) affect the quantity and quality of spray deposition on peanut plants at the vegetative and reproductive growth stages. Two greenhouse experiments were performed on peanut plants at the V1 and R1 growth stages. Experiment 1 treatments included three droplet sizes: medium (flat fan XR 11002), very coarse (TT 11002), and extremely coarse (AIXR 11002). Experiment 2 treatments were five spray nozzles: hollow cone (TXA 8002 VK), twin flat fan (TTJ60 11002), air induction flat fan (AIXR 110025), drift guard twin flat fan (DGTJ60 11002), and extended range flat fan (XR 11003). Spray deposition values were determined using a solution of brilliant blue dye sprayed by a CO2-pressurized backpack sprayer. The medium droplet size provided higher spray deposition on peanut plants at the V1 and R1 growth stages. Increasing the droplet size from medium to extremely coarse reduces spray deposition at the V1 growth stage. Spray deposition uniformity increased as droplet size increased at the V1 growth stage. The spray uniformity decreased at the R1 growth stage as the droplet size increased. The flat fan XR 11003 (medium droplet) and hollow cone nozzle TXA 8002 VK (fine droplet) provided a higher spray deposition on peanut plants at both growth stages. The spray nozzles that provide a higher spray deposition did not perform well on spray uniformity. [ABSTRACT FROM AUTHOR]

A large seed mutant, TG 89 having a 76.7% increment in hundred kernel weight in comparison to its parent TG 26, was isolated from an electron beam-induced mutagenized population. Studies based on environmental scanning electron microscopy of both parent and mutant revealed that the mutant seed cotyledon had significantly bigger cell size than parent. A mapping population with 122 F2 plants derived from the mutant and a distant normal seed genotype (ICGV 15007) was utilized to map the QTL associated with higher HKW. Bulk segregant analysis revealed putative association of three markers with this mutant large seed trait. Further, genotyping of F2 individuals with polymorphic markers detected 14 linkage groups with a map distance of 1053 cM. QTL analysis revealed a significant additive major QTL for the mutant large seed trait on linkage group A05 explaining 12.7% phenotypic variation for the seed size. This QTL was located between flanking markers AhTE333 and AhTE810 having a map interval of 4.7 cM which corresponds to 90.65 to 107.24 Mbp in A05 chromosome, respectively. Within this genomic fragment, an ortholog of the BIG SEEDS 1 gene was found at 102,476,137 bp. Real-time PCR revealed down-regulation of this BIG SEEDS 1 gene in the mutant indicating a loss of function mutation giving rise to a large seed phenotype. This QTL was validated in 11 advanced breeding lines having large seed size from this mutant but with varied genetic backgrounds. This validation showcased a highly promising selection accuracy of 90.9% for the marker-assisted selection. [ABSTRACT FROM AUTHOR]

This study reports the utilization of raw agricultural biowaste groundnut shell (GS) as a potential immobilization matrix for an isolated bacterial consortium as a sustainable means to remove 4-nitrophenol (4-NP). Optimization of five parameters such as immobilization matrix size, matrix dosage, pH, temperature, and agitation and their three levels was done through Taguchi Orthogonal Array approach by Qualitek-4 software. Taguchi methodology indicated the optimum reaction conditions to be (in order of their significance) agitation speed (100 rpm), immobilization matrix dosage (4 g), matrix size (800 µm), pH (9), and temperature (32 °C), resulting in an overall enhancement of 57.30% 4-NP removal efficiency under the optimized conditions. GS-immobilized cells exhibited an improved substrate removal efficiency and high substrate tolerance over free cells, indicating the synergistic effects of adsorption and biodegradation on the removal process. The GS immobilized cells could remove 1000 mg l−1 of 4-NP as opposed to only 700 mg l−1 by the free cells. Biodegradation kinetics were analyzed using various substrate inhibition models, and Haldane model fitted the experimental data reasonably well. GS immobilized cells retained a stable activity of 85.5 ± 3.48% for 45 days when stored at 4 °C and could be efficiently reused for 4 consecutive cycles. Thus, utilizing untreated agricultural wastes like GS will be a cost-effective alternative to conventional immobilization matrices in small-scale industries and can be a step towards sustainable agro-waste management and contaminated wastewater treatment. [ABSTRACT FROM AUTHOR]

Two species of thrips, Rhipiphorothrips concoloratus Zhang and Tong and Trichromothrips antidesmae Li, Li and Zhang, under the family Thripidae are recorded new to India. The diagnostic characters of both the species are discussed. In addition, Euphysothrips minozzii Bagnall of the family Thripidae is redescribed with illustrations based on the specimens collected on an agriculturally important new host plant, Groundnut. The hypothesis of E. minozzii being associated with fungus is discussed. The partial sequence data of mitochondrial cytochrome c oxidase (mtCOI) for E. minozzii is generated and submitted to the Barcode of Life Data System (BOLD). The generated barcode sequence of the species is a novel contribution in global database. [ABSTRACT FROM AUTHOR]

The worldwide economic crop groundnut is infected by aflatoxigenic Aspergillus species (AAS), for which the soil is the main inoculum reservoir. Thus, to assess the spatiotemporal dynamics and association of AAS populations with biophysical factors, a total of 300 soil samples were collected (pre-planting, flowering, and physiological maturity) from five groundnut-growing districts in three zones of Ethiopia in 2019. AAS were isolated by dilution plating and their aflatoxin-producing potential determined using special media and UV light. Logistic regression models were used to analyze the effect of biophysical factors on AAS population dynamics. AAS populations varied across groundnut-growing districts and over time. In the Fedis district, the highest relative density of A. flavus non-sclerotia producer (NSP) strain (30.1%) and small sclerotia (S-strain) producers (26.1%) were recorded at pre-planting and maturity, whereas large sclerotia (L-strain) producers (4.1%) and A. parasiticus (11.6%) were recovered from the Kucha district at flowering and maturity, respectively. From Humbo and Kucha districts, the highest populations of A. flavus (10.3 × 104 cfu/g soil) and A. parasiticus (5.5 × 104 cfu/g soil), respectively, were recorded at maturity. The smallest population of AAS had a strong association with altitudes > 1640 m a.s.l., higher pH (> 7), low organic matter (0.572–1.378), and sand-sandy loam soil, factors which can be considered as management options. A. flavus S-strain prevalence had a positive relationship with increased soil temperature > 30 °C, which highlights the need for mitigation strategies as the climate warms. [ABSTRACT FROM AUTHOR]

Late leaf spot (LLS) is the most important foliar disease of peanuts in Argentina and in other peanut production areas, causing defoliation and yield losses. In this study, six isolates obtained from symptomatic leaflets collected in Córdoba, Argentina, were characterized based on the morphology of the colony and conidia, as well as molecularly using a combination of the 28S nrRNA gene (LSU), the internal transcribed spacer regions and the intervening 5.8S nrRNA gene (ITS) of the rDNA operon, and the second largest subunit of RNA polymerase II (RPB2). Pathogenicity was confirmed using the detached leaf method, inoculating a spore suspension. Mycelial growth was evaluated on four culture media: peanut oatmeal agar (POA), potato dextrose agar (PDA), peanut leaflet extract agar (PLA) and peanut seed extract agar (PSA), with PSA and PDA showing the greatest radial growth. This is the first study of N. personata obtained in the peanut-producing region of Argentina. [ABSTRACT FROM AUTHOR]

Sclerotium rolfsii, causal agent of stem rot of groundnut, can cause yield losses up to 80%. Using environmentally friendly control practices is a plausible approach for the management of the pathogen. The aims of the study were (i) to determine biological control potential of 16 native isolates of Trichoderma harzianum and T. aggressivum f. aggressivum against S. rolfsii in vitro (ii) to select Trichoderma isolates showing significant antagonism and (iii) to establish their biocontrol potentials by comparing several plant growth parameters in vivo. Dual culture tests were used for in vitro experiments. In vivo experiments were as follows: 1- Negative control (only groundnut seedlings); 2- Positive control (groundnut seedlings + S. rolfsii); 3- Treatment A (groundnut seedlings + Trichoderma isolate); and 4- Treatment B (groundnut seedlings + S. rolfsii + Trichoderma isolate). No lesion developed on plants in the negative control and majority of the treated plots. Significant (P˂0.01) differences in pod yield, root dry weight, biomass and lesion length in the treated plots were detected. There were significant (P˂0.01) differences among the treatments. The highest values of pod yield, root dry weight and biomass were found in treated plots in which only isolates of T. harzianum and T. aggressivum f. aggressivum were applied. However, no significant (P˂0.01) difference between the treatment B and the negative control was determined in terms of growth parameters. The selected native isolates of the Trichoderma species not only suppressed S. rolfsii but also enhanced growth parameters of groundnut, indicating their biocontrol potential and plant growth promoting features. [ABSTRACT FROM AUTHOR]

Plant-specific TIFY transcription factor family is characterized by a highly conserved TIFY domain. Four sub-families ZML, PPD, TIFY, and JAZ (Jasmonate ZIM domain), participate in a wide diversity of developmental and stress-responsive processes. Here, 29 Arachis hypogaea (peanut) TIFY family genes are identified and characterized by conserved domain distribution, exon–intron pattern, and phylogenetic clustering. 6 ZMLs, 2 TIFYs, 1 PPD, and 20 JAZ sub-family genes are confirmed in AhTIFY family. Since allotetraploid peanut contains two progenitor sub-genomes, 14 homeologous gene pairs are obtained, also showing positional or functional homeology, based on comparative chromosomal localization and comparative tissue expression, respectively. Transcriptomic studies of Peanutbase show tissue-specific expression, drought, and nematode-responsiveness of AhJAZs. It reveals contribution of JA-signaling pathway in the development and stress management of a globally important oil-crop peanut, finally to enhance its agricultural production. In connection to AhJAZs, this study has scrutinized legume JAZs as a whole, to find out few interesting features of the legume JAZs, viz., (a) the absence of JAZ5, 10, 11 and (b) the presence of Jas intron in the JAZ1s, subjected to alternative splicing, contrasted with Arabidopsis. Most intriguingly, in 13 legume JAZ12s, predicted peptides from the in-frame coding sequence containing three-nucleotide periodicity and termination codon within the Jas intron/3′-intron show sequence similarity to rhizobial ABC transporter-type proteins. Predicted peptides appear to be encoded by these intronic sORFs to modulate rhizobial transporter proteins and thereby to influence the symbiotic relation of the legume crops through a unique way of JAZ utilization in the legumes. [ABSTRACT FROM AUTHOR]

Peanut (Arachis hypogaea L.) is a geocarpic plant, which absorbs nutrients not only through roots but also through pods. However, the effect of nitrogen fertilizer application in pod area on pod gene expression and peanut yield is unknown. In this study, we determined the pod yield, dry matter accumulation, nitrogen accumulation in different organs under different nitrogen treatment in root zone and pod zone. The results showed that pod area application of nitrogen led to significantly higher pod yield to compare with the control. The application of 60 kg/hm2 nitrogen at the pod area led to the highest pod yield, full fruit rate and plant nitrogen content. 15N directly absorbed by pods was mainly accumulated in the shell at early stage of pods development, and then transferred to seeds at later period. However, the ratio of 15N absorbed directly by pods from soil was low, only about 10%. To understand the underlying molecular mechanisms, immature pods of different developmental stages were collected for gene expression analysis. The expression levels of several genes encoding ABC type transporter family, nitrate reductase, nitrite reductase and glutamine synthetase increased in different stages of pod development upon pod area nitrogen application. These results indicated that the efficiency of N assimilation and glutamate metabolic cycle in pods was increased under pod nitrogen application. The expression levels of several genes in gibberellin and brassinolide biosynthesis pathways were also up-regulated, suggesting that these two hormones were involved in the promoting effect of pod nitrogen application on pod growth. [ABSTRACT FROM AUTHOR]

The peanut rich in oleic acid in seed oil, also known as high oleic peanut, renders its products superior in human healthy diet, long shelf life and high oxidative stability in food and oil processing. High oleic peanut varieties in China are derived from a handful of high oleic donors with limited genetic background. Improvement of high oleic peanut cultivars by integrating key target traits is crucial for both food security and germplasm enhancement. Several superior high oleic peanut lines have been developed by marker assisted backcrossing in our breeding program. The objective of present study is to characterize bacterial wilt disease resistance and yield related traits in these novel peanut lines. The two-year disease nursery survival rates were used as an indicator for bacterial wilt resistance, and the diagnostic markers identified by QTL mapping were used for molecular verification. Genetic background of high oleic peanut lines was estimated by 40 K genotyping by target sequencing (GBTS) SNP panel. Preliminary and regional yield tests were performed for selected breeding lines in 2021. As a result, an elite high oleic peanut accession Yuhua183 was identified, inheriting the superior characteristics of its recurrent parent such as resistance to bacterial wilt, high shelling percentage and early maturity. The development of Yuhua183 broadened the genetic background of high oleic peanut germplasm, providing valuable genetic resources for peanut breeding and further utilization. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of replacing soybean meal with peanut meal on milk production, chemical and fatty acid composition, nutritional quality indicators of the lipid fraction, and the economic viability of the diets. Twelve crossbred cows in the initial lactation third, with a bodyweight of 545 ± 37 kg and average milk production of 28 kg/day of milk were distributed in a 4 × 4, triple Latin square design. The treatments consisted of diets with substitution levels of soybean meal for peanut meal (0; 330; 670; and 1000 g/kg in DM). The peanut meal inclusion to replace soybean meal in the diets provided a decreasing linear effect for the protein (P = 0.02) and casein (P = 0.01) concentration in milk. Milk production, total solids concentration, feed efficiency, fatty acid composition, and nutritional quality indicators of the milk lipid fraction were not influenced by the substitution levels. The diet cost per kg DM decreased due to the peanut meal inclusion as a protein source. The partial or total substitution of soybean meal for peanut meal in the feedlot cows diet reduces the cost of feed, without affecting milk production and total solids yield. [ABSTRACT FROM AUTHOR]

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Thrips (Thysanoptera: Thripidae) are major pests of peanut (Arachis hypogaea L.). They cause feeding damage and indirect injuries transmitting plant viruses. In Argentina, peanut is commonly affected by thrips. The crop also is infected by groundnut ringspot orthotospovirus, a virus transmitted by thrips vectors. However, in the country, information about thrips in peanut is very scarce. A 3-yr study was conducted to characterize the species composition and thrips population dynamics in the main peanut-producing area in Argentina. Frankliniella schultzei (Trybom), followed by Caliothrips phaseoli (Hood) were the most abundant species. Together the two species accounted for ~ 95-99 % of the total adult thrips captured in each season. Significant different abundances were observed among these two thrips species throughout each peanut growing season. Nevertheless, the temporal dynamics of F. schultzei and C. phaseoli showed a similar trend in the three study years. In general, the colonization by F. schultzei started in late December and their population increased from the second half of January peaking around the first half of February. The highest densities of F. schultzei occurred simultaneously in foliage and flowers during the warmer months of the year. The C. phaseoli population inhabited on foliage and peaked in late February or mid-March. Other species collected were Frankliniella occidentalis (Pergande), Frankliniella gemina Bagnall, and Thrips tabaci (Lindeman). This study mentions F. gemina in peanut for the first time. Results show that F. schultzei and C. phaseoli are common thrips pests in peanut in Argentina and provide new information about the population dynamics of these thrips species in peanut crops. [ABSTRACT FROM AUTHOR]

Genetic advancement and gains in yield and related traits are dependent on the selection of best combiner parents and progenies under the prevailing growing conditions. This study was conducted to determine the combining ability effects of eight selected drought-tolerant groundnut parental lines and their F2 progenies under drought-stressed (DS) and non-stressed (NS) conditions to determine the gene actions involved in the inheritance of the studied traits and identify the best parents and progenies for further improvement of the crop for moisture stress tolerance. Experiments were conducted at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) in India during 2020 cropping season. Data on some of the important physiological, yield and yield component traits were collected. The general combining ability (GCA) effects of parents were significant (P < 0.05) for all assessed traits under all testing conditions, except for PB under DS and NS conditions in the glasshouse. The specific combining ability (SCA) effects of progenies were significant (P < 0.05) for all traits, except for PH across all testing environments and PB under field conditions. The genotype ICGV 10178 was the best general combiner with positive contribution and significance to SCMR, PY, SHP, KY, TBM and HI and reduced SLA. Crosses ICGV 10178 × ICGV 11369, ICGV 10373 × ICGV 15083, ICGV 98412 × ICGV 15094 and ICGV 10178 × ICGV 98412 were the best specific combiners for enhanced pod yield and drought tolerance. The GCA was found predominant over the SCA effect for the inheritance of PY, KY and TBM. Higher GCA: SCA rations were recorded for PY and KY under both DS and NS conditions, and SCMR, SLA and TBM under DS condition suggesting the predominant role of additive genes conditioning the inheritance of these traits. Therefore, the above new progenies are useful populations for developing improved pure line groundnut varieties with high pod yield and drought tolerance. [ABSTRACT FROM AUTHOR]

In this work, peanut (Arachis hypogaea) skin, a by-product generated by the agricultural production of its seeds, was employed as a precursor in the preparation of an adsorbent for the 2,4-D removal in water. The skins were treated with sulfuric acid and characterized by different techniques. The adsorption was favored at acid pH = 2 with pHpzc = 6. The dosage of 0.9 g L−1 was considered ideal, obtaining satisfactory indications of removal and capacity. The kinetic curves were well represented by the general order model, with the equilibrium reached quickly in the first 30 min for all concentrations. Adsorption isotherm studies showed that the increase in temperature negatively affected the herbicide adsorption, obtaining a maximum capacity of 246.72 mg g−1, by the Langmuir isotherm at 298 K. The remarkable adsorption efficiency presented by the adsorbent can be associated with the presence of new functional groups on the adsorbent surface generated after the acid treatment. Thermodynamic parameters confirmed the exothermic nature of the adsorptive system. In the treatment of synthetic wastewater consisting of a mixture of herbicides and salts, a high removal efficiency (72%) of herbicides was obtained. Therefore, the development of an adsorbent derived from peanut (Arachis hypogaea) skin treated with sulfuric acid is an excellent alternative, generating remarkable removal results towards 2,4-D herbicide. [ABSTRACT FROM AUTHOR]

Seedlings of groundnut (Arachis hypogaea L.) 'TG-51' were raised in sand culture in presence of three different concentrations of cadmium (100, 300 and 500 µM) and two concentrations of zinc (50 and 150 µM) along with their combinations. In general, the root accumulated several times higher content of both the metals than leaf. It was noted that uptake of Cd by root decreased in combined treatment in comparison with the sole application of cadmium. The dry weight of root, stem, leaf as well as the whole seedling significantly decreased under cadmium stress compared to unstressed control. Zinc supplementation in the growing medium minimized the adverse effects of cadmium on seedling growth to some extent but could not completely override it. Presence of zinc in combination with cadmium could further the enhancement of proline accumulation under heavy metal stress at 100 and 300 µM Cd but not at the highest concentration. Zinc supplementation in combination with cadmium also lowered the damaging effect of cadmium on leaf membrane to some extent.Higher supplement of Zn was able to enhance dismutation of Cd-triggered superoxide radical by superoxide dismutase enzyme, facilitating its subsequent detoxification through the involvement of peroxidase and catalase enzymes, thereby highlighting its protective role against oxidative damage under heavy metal stress. The results of PCA indicated that strong positive loadings of dry weight of root, leaves as well as whole seedling at PC 1 (55.7%) while the activities of SOD, GPOX and catalase enzymes at PC 2 (16%) mostly contributed towards discrimination among different treatments. [ABSTRACT FROM AUTHOR]

During gene transformation, selection makers are important for efficient screening of the transgenic lines. The commonly used selection marker genes in plants such as neo, bar and hpt confer antibiotics resistance or herbicide resistance to the transgenic lines, which may have uncertain effects on environment and biosafety. Other selection marker genes with non-toxic products such as xylose isomerase, phosphomannose isomerase and β-glucuronidase are exogenous genes and may also have side effects on transgenic plants. Hence, endogenous and safe marker genes are desirable. Here, a new vector designated pCAMBIA2300-35S-OCS-AhFAD2B was constructed, in which the NeoR gene was replaced by AhFAD2B gene as a reporter gene. FAD2B catalyzes the formation of linoleic acid from oleic acid. High oleic acid peanut (Arachis hypogaea L.) (oleic acid content is >70% of the total fatty acids) variety Kainong1715 was used for transformation by Agrobacteriumtumefaciens injection through peanut calyx tube. A total of 688 seeds were harvested, and the oleic acid content of each seed was measured using near infrared reflectance spectroscopy (NIRS). The oleic acid content of 93 seeds was found to be less than 70% indicating that these seeds had been transformed. Further validation by PCR amplification demonstrated that these seeds were true transgenic seeds. AhFAD2B as a reporter gene in peanut could greatly improve screening efficiency of transgenic seeds using NIRS. In addition, linoleic acid, the catalytic product of AhFAD2B, is the essential fatty acid for human health. This is the first report on the development of marker using endogenous gene in peanut. [ABSTRACT FROM AUTHOR]

Peanuts are grown in both developed and developing countries, and their cultivation has been considerably expanded to semiarid and arid regions. In this study, we investigated the ROS-scavenging activity and bioactive composition of hydric stress-tolerant (BR1, Senegal 55,437, L7 Bege, F.M424B) and -susceptible peanut genotypes (LViPE-06, LGoPE-06 and Tatu). Peanut grains were examined for their fatty acid profile by GC-FID, tocopherol content by HPLC-FLD, phenolic composition by LC–ESI-LTQ-Orbitrap-MS, and for their ability to deactivate ROS (ROO·, HOCl, O2·− and OH·). All genotypes had the same fatty acid profile. The highest total tocopherol content was found in the drought-tolerant genotype BR1 (80.38 mg·100 g−1), which corresponded to nearly twofold that found in most peanut genotypes. BR1 grains showed the greatest capacity to deactivate ROO•, whilst LGoPE-06, F.M424B, BR1 and LViPE-06 grains were the most active against HOCl. The greatest OH• scavenging capacity was observed for Senegal 55,437 genotype (drought tolerant). LC–ESI-LTQ-Orbitrap-MS analysis detected a total of 26 polyphenols, including 2,6-dihydrobenzoic acid, 2,5-dihydroxybenzoic acid, protocatechuic acid-O-hexoside and catechin-O-hexoside, which were identified for the first time in unpeeled peanuts. To conclude, both drought-tolerant and -susceptible peanut genotypes did not have any significant influence on the content of fatty acids and tocopherols and ROS scavenging, although the drought-tolerant genotype BR1 stood out significantly from the others. [ABSTRACT FROM AUTHOR]

Jasmonate ZIM domain (JAZ) proteins are the key negative regulators of jasmonate signaling, an important integrator of plant–microbe relationships. Versatility of jasmonate signaling outcomes are maintained through the multiplicity of JAZ proteins and their definitive functionalities. How jasmonate signaling influences the legume-Rhizobium symbiotic relationship is still unclear. In Arachis hypogaea (peanut), a legume plant, one JAZ sub-family (JAZ1) gene and one TIFY sequence containing protein family member (TIFY8) gene show enhanced expression in the early stage and late stage of root nodule symbiosis (RNS) respectively. In plants, JAZ sub-family proteins belong to a larger TIFY family. Here, this study denotes the first attempt to reveal in planta interactions of downstream jasmonate signaling regulators through proteomics and mass spectrometry to find out the mode of jasmonate signaling participation in the RNS process of A. hypogaea. From 4-day old Bradyrhizobium-infected peanut roots, the JAZ1-protein complex shows its contribution towards the rhizobial entry, nodule development, autoregulation of nodulation and photo-morphogenesis during the early stage of symbiosis. From 30-day old Bradyrhizobium infected roots, the TIFY8-protein complex reveals repressor functionality of TIFY8, suppression of root jasmonate signaling, modulation of root circadian rhythm and nodule development. Cellular localization and expression level of the interaction partners during the nodulation process further substantiate the in planta interaction pairs. This study provides a comprehensive insight into the jasmonate functionality in RNS through modulation of nodule number and development, during the early stage and root circadian rhythm during the late stage of nodulation, through the protein complexes of JAZ1 and TIFY8 respectively in A. hypogaea. [ABSTRACT FROM AUTHOR]

Argentina is one of the main peanut (Arachis hypogaea L.) exporting countries with the major peanut-growing area located in the province of Córdoba. During the 2015–2016 growing season, severe outbreaks of an orthotospovirus-like disease occurred in a number of commercial peanut fields. The aim of this work was to determine the prevalence of orthotospoviruses and their incidence in peanut. In DAS-ELISA, all samples collected from symptomatic plants reacted with antisera to groundnut ringspot virus/tomato chlorotic spot virus (GRSV/TCSV) and tomato spotted wilt virus (TSWV). RT-PCR was performed with a single pair of primers for conserved regions of the GRSV, TCSV and TSWV nucleoprotein (N) genes, and digestion with restriction enzymes, allowed the identification of the pathogen as GRSV. The results were confirmed by sequencing of the N gene. Diseased peanut plants were observed in 30 out of 81 surveyed fields located in the north-central region of the peanut-growing area. In that region, the disease incidence was evaluated in four commercial fields, recorded values from 3% to 47.25% with a mean disease incidence of 18.69%. Our study reported for the first time a significant outbreak of GRSV in peanut in Argentina and provide information on the occurrence and distribution of some Orthotospovirus species. [ABSTRACT FROM AUTHOR]

Severe little leaf and excessive shoot proliferation symptoms typical of the peanut little leaf (PnLL) disease were observed in different peanut (Arachis hypogaea) fields, variety K-6, at Kadiriand Gooty regions, of Andhra Pradesh, India, during the monsoon season of 2018–19. Disease incidence was 2–3%. The phytoplasma etiology of the recorded disease was confirmed by amplifying ~1.25 kb DNA products of 16S rRNA gene from symptomatic plants using nested polymerase chain reaction with phytoplasma specific primers, P1/P7 and R16F2n/R16R2, respectively. A further confirmation of the phytoplasma etiology was obtained by amplification of 840 bp, 1094 bp and 465 bp DNA fragments using phytoplasma specific primers targeting secA, tuf and SAP11 genes, respectively. Sequence and phylogenetic analyses of the amplified 16S rRNA, secA, tuf and SAP11 genes revealed that the detected phytoplasma is a member of the peanut witches'-broom phytoplasma group or 16SrII group ('Candidatus Phytoplasma australasia'). Also, on the basis of computer-simulated RFLP (= in silico RFLP) analysis of amplified 16S rRNA gene, the detected phytoplasma was assigned to subgroup D (16SrII-D). Parthenium hysterophorus plants showing witches' broom and Cleome viscosa plants with little leaf symptoms, both collected in the mentioned peanut fields were also infected by similar strain of phytoplasma which proved to be identical with each of the molecular marker employed to the peanut-infecting agent in India. This is the first report on the association of 'Ca. P. australasia' (16SrII-D subgroup phytoplasma) with PnLL disease in India. [ABSTRACT FROM AUTHOR]

Yield losses due to Groundnut ringspot virus – GRSV (genus Orthotospovirus) infection have been observed across major peanut (Arachis hypogaea L.) growing areas in Brazil. However, effective management systems capable of minimizing GRSV damage are not yet available. The aim of the present study was to verify the effectiveness of the pyraclostrobin (a strobilurin fungicide reported as a potential activator of natural, large–spectrum plant defense mechanisms) in the management of GRSV in peanuts. Two independent field experiments were carried out in commercial peanut areas with a natural occurrence of GRSV. A completely randomized block design was used with a 5 × 2 factorial scheme, including four replicates, five peanut cultivars ('Runner IAC 886', 'IAC OL4', 'IAC 503', 'IAC 505', and 'Granoleico') and two treatments (with and without pyraclostrobin application). At 80 and 100 days after sowing, visual disease severity scores and the number of infected plants were evaluated, followed by virus quantification in the leaf tissues and yield. The cultivars 'Granoleico' and 'IAC 503' displayed the highest levels of GRSV susceptibility. Pyraclostrobin was found to be effective in reducing the number of GRSV–infected plants, as well as in attenuating disease severity. In addition, pyraclostrobin was able to promote significant yield increase. Even though the mechanism(s) of pyraclostrobin action against GRSV remain elusive, this fungicide can be regarded as a potential component for viral disease management programs in peanuts. [ABSTRACT FROM AUTHOR]

Peanut red spider mite, Tetranychus ogmophallos, exhibits a peculiar dispersal behavior using silk balls, which involves clustering of mites and spinning of webs at the top of plants. Such a dispersal mechanism has not been studied for this species yet. Therefore, this study aimed at using mathematical models to describe aerial dispersal and silk ball formation of peanut red spider mite on peanut plants. The influence of wind speed, generated by a wind tunnel, on the dispersal of mites was studied in two experiments, one with 500 mites per plant and one with 1000 mites per plant, and six wind speeds (5, 10, 15, 20, 25, and 30 km h−1) for each mite density. The proportion of displaced mites and the distance they were blown were measured. Another series of experiments considered the formation of silk balls to assess how fast balls were formed as a function of time and the number of mites present on a peanut plant. Data from the wind tunnel experiments were analyzed by logistic regression and multiple regression to assess the proportion of displaced mites and the distance moved, respectively, as functions of wind speed and the initial density of mites on the donor plant. The distribution of dispersal distances from the donor plant was fitted by a mathematical model proposed by Ricker (J Fish Res Board Can 11:559–623, 1954). The number of mites moving upwards on a plant to be involved in silk ball formation was modeled as a function of time based on the initial number of spider mites and their estimated birth, death and movement rates per capita. Logistic regression was used to analyze the presence of balls as a function of time elapsed since a plant was infested with spider mites. Finally, non-linear regression was applied to link ball size to the total number of mites occupying the ball. The data analyses revealed that wind speed had a significant positive effect on take-off probability and distance moved by individual mites, whereas mite density had little influence. Ricker's model adequately described the distribution of dispersal distances. The models describing silk ball formation also described data very well. Ball size was found to increase almost linearly with the number of mites found in the ball. We expect that the knowledge provided by the present study will help to develop efficient management strategies against T. ogmophallos in peanut crops as dispersal seems to be a key factor in the species' capability to become a serious pest. [ABSTRACT FROM AUTHOR]

We detected and compared the mRNA and protein expression levels of immunity-associated and symbiosis-associated genes in peanut (Arachis hypogaea) roots inoculated with entomopathogenic fungus M. anisopliae or the phytopathogenic fungus Fusarium oxysporum, by RT-qPCR and parallel reaction monitoring (PRM). The selected genes were mainly associated with plant–fungus interactions, signal transduction, regulation of cell death, nitrogen or iron metabolism, nutrient acquisition or transport, and compound synthesis based on previous transcriptome analysis. The results showed that the host basal defense responses were significantly inhibited by both M. anisopliae and F. oxysporum, which suggests that both fungi actively suppress the host immunity for successful colonization and infection. However, only F. oxysporum induced a strong host hypersensitivity, which indicates that the host is strongly resisting F. oxysporum but potentially allowing M. anisopliae. Additionally, the genes (SYMRK, CaM, CCaMK, FRI2, ABCC2, F6H1, SCT, NRT24 and LTP1) related to symbiosis and growth were distinctively observed with an up-regulated expression following M. anisopliae treatment, which implies that the host was actively initiating the establishment of symbiosis with the fungus. This study revealed a synergistic relationship between host immunosuppression and the promotion of symbiosis during interactions with M. anisopliae. It suggested that M. anisopliae benefited plant for symbiotic relationship, in addition to controlling herbivorous insects as an entomopathogen. [ABSTRACT FROM AUTHOR]

Cold stress is one major threats to field crops. The cold tolerant ability is a key limiting factor for the popularization of peanut (Arachis hypogaea L.) in cold areas. Our previous research showed three key metabolic change time points of peanut buds in response to low temperature. The present study applied iTRAQ proteomic to further quantify differentially expressed proteins in three key metabolic change time points. A total of 2684 non-redundant proteins and 333 differentially expressed proteins across the three cold stress treatment points were identified. The results enrich the cold stress regulation network and provide useful information for further improving the ability of peanut under cold stress. [ABSTRACT FROM AUTHOR]

Breeding drought tolerance in groundnuts cultivars would reduce yield losses due to drought stress in rain-fed growing areas. The mode of gene action governing the inheritance of drought tolerance and secondary traits was investigated by mating 30 lines according to North Carolina design II scheme. The parents and resulting 75 F2 progenies were grown in a split plot arrangement using an alpha lattice design, with two replications under drought and non-stressed environments for two seasons. The trials were conducted over two seasons, in 2017 A and 2017 B at the National Semi-Arid Resources Research Institute, located 27 km west of Soroti town in eastern Uganda. The results showed highly significant differences between families and parents for drought tolerance and agronomic traits. Traits including BIO, DTI(PY), DTI (BIO) and HI had the highest correlations with PY. HI was positively associated with no. of pods per plant under drought stressed and non-stressed environments. Under drought stressed environment, GCA was more important than SCA for traits such as SCMR2, and HI. However, SCA was more important than GCA for traits such as SCMR2, PY, BIO, DTI(PY), and DTI (BIO). The study identified parents with best GCA and combinations with best SCA effects for both agronomic and drought tolerance traits. The new population is shown to be a valuable genetic resource for variety selection and improvement of groundnut for adaptation to the drought prone areas of Uganda. [ABSTRACT FROM AUTHOR]

The study involved purification of trypsin inhibitor from the seeds of Indian peanuts (Arachis hypogaea), a member of leguminosae family. The inhibitor was purified to homogeneity via three sequential step procedure i.e., salt precipitation to anion-exchange chromatography. The purity and molecular mass was detected using SDS PAGE analysis i.e. ~ 16 kDa. The purified inhibitor termed as Peanut Trypsin Inhibitor (PTI) which inhibits trypsin belonging to serpins family. Anti- neoplastic potential on breast cancer cells (MCF-7) and normal Human Embryonic Kidney cells (HEK) was determined using MTT assay. PTI exhibited IC50 value of ~ 18.412 µg/mL in HEK cells compared to ~ 9.635 µg/mL in MCF-7 cells. The values were quite comparable to curcumin, the standard anticancer drug demonstrating IC50 values of ~ 21.581 µg/mL and ~ 7.135 µg/mL in HEK and MCF-7 respectively. Therefore, we conclude that PTI may be used as supplement along with the conventional drugs for increased efficacy in the treatment of cancer. [ABSTRACT FROM AUTHOR]

The objective of the work is to evaluate whether Bradyrhizobium sp. SEMIA6144 and Azospirillum brasilense Az39 can be used for inoculation to mitigate the negative effect of water restriction on growth of Arachis hypogaea. In this study, nitrogenase activity was determined by measuring the H2 evolution in an open-flow system, and N and C concentration in plants were determined by Elemental Analyzer. Lipid peroxidation and polyamines (PA) levels were analyzed by HPLC. The results showed that the restrictive water condition (RWC) caused an 80% inhibition of the N fixation rate. Although both single and double inoculation favored peanut growth under RWC, the inoculation with SEMIA6144 was better. Peanut plants have higher numbers of nodules in the roots when inoculated with SEMIA6144 in the absence of Az39, although it was observed that the inoculation with Az39 favored root development thus allowing the appearance of more infection sites in peanut roots. In double inoculation, the demand for N in the peanut was met with greater effectiveness. PAs found in leaves were putrescine, spermidine, and spermine. The results show that SEMIA6144 inoculation reversed the negative effects of RWC on growth and nodulation peanut parameters. Simultaneous application of SEMIA6144 and Az39 improved early nodulation, efficiency in N fixation and total N, thus increasing the tolerance of A. hypogaea to RWC. Our findings provide new insights in the context of mixed inoculation and improvement of peanut production in a limited water environment. [ABSTRACT FROM AUTHOR]

Photocatalysts are a boon to the emerging pollution and environmental hazards posed due to the use of dyes in industries. Existing conventional methods are sometimes expensive and might release toxic by-products. A much greener approach to the challenge is the usage of nanoparticles which is a much safer and an environment friendly method to degrade the harmful and toxic chemicals. Hence, in the present study we have come up with a greener way of synthesizing spherical shaped tin oxide nanoparticles (SnO2 NPs) as a photocatalyst, utilizing Arachis hypogaea (A. hypogaea). The methanolic extract of A. hypogaea shell was used for preparation of SnO2 NPs having an average particle size of 60 nm, which was then used as the catalyst for Congo red dye degradation. The effect of dye concentration, catalyst concentration and irradiation time on the percentage of degradation and the optimization of the process was studied by Response Surface Methodology (RSM) based on Box–Behnken design. The obtained RSM model with R2 = 98.60% showed a satisfactory correlation between the predicted and experimental values of dye removal. 89% degradation was achieved under the optimum condition (1 mg photocatalyst concentration, 1 mM dye concentration) after 50 min time. In addition, the antifungal activity of the prepared nanoparticles was also carried out and revealed better results against Aspergillus niger (A. niger) than Aspergillus flavus (A. flavus), at higher concentration of SnO2 NPs. Thus we were able to synthesize a photocatalyst using an agricultural waste which can degrade an azo dye and also exhibits antifungal activity. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the changes in leaf physiological parameters to abiotic stress induced by different levels of cement dust. On day 15, Arachis hypogaea L. plants (sowing day was considered as day 0) were divided into six groups, and cement was sprinkled over plants with the help of hand pump, twice a week at T1 (5 g pot−1), T2 (8 g pot−1), T3 (10 g pot−1), T4 (15 g pot−1), T5 (20 g pot−1), and T0/control (0 g pot−1), until fruit maturity. Morphometric parameters such as root and shoot length, leaf area, and seed weight were significantly higher in T0, while the minimum was recorded in T5. Physiological analyses of leaves and roots revealed a remarkable reduction (p < 0.05) in sugar, amino acid, and protein contents, while the concentration of enzymatic antioxidants was increased in cement-treated plants. The concentration of abscisic acid in leaves was significantly higher in treatment groups as compared with control, while gibberellic acid concentration was low. Strikingly, cement dust decreases the level of leaf photosynthetic pigments, reduces stomatal conductance, and adversely affects photosynthesis. Leaf histological analysis revealed confirmatory evidence of stomatal closure, cell damage, reduced cell area, and abridged leaf thickness. Salient features of the present study provide useful evidence to estimate cement dust as a critical abiotic stress factor, which has adverse effects on photosynthesis, leaf anatomical features, stomatal functioning, and productivity. Our work opens new avenues for a deep portfolio of cement-based stress mediating pathophysiology in Arachis hypogaea. [ABSTRACT FROM AUTHOR]

The peanut red spider mite, Tetranychus ogmophallos Ferreira and Flechtmann (Acari: Tetranychidae), is an important pest of peanut in Brazil and is considered a quarantine pest in other countries. This study investigates the development, reproduction, survival and life table parameters of T. ogmophallos on five peanut cultivars—three with high levels of oleic acid [high oleic] and recently released: Granoleico, IAC OL 3 and IAC 503; and two regular and previously used by farmers: Runner IAC 886, IAC Tatu ST 3—and two breeding lines (L. 8008 and L. 322) in the growth chamber. There were differences between the developmental times of all immature stages, the oviposition period, fecundity and adult longevity of T. ogmophallos reared on the peanut cultivars and breeding lines. The longest duration of the immature stage and lowest fecundity occurred on cultivars Granoleico and Runner IAC 886, and breeding line L. 322, which also displayed the lowest intrinsic rate of increase (r), finite rate of increase (λ) and net reproductive rate (R0) and the shortest mean generation time (T). The highest fitness occurred on the IAC Tatu ST, IAC OL 3, IAC 503 and L. 8008. Our study shows that peanut cultivars belonging to the group with high oleic trait and recently released (IAC OL 3 and IAC 503) are susceptible to T. ogmophallos, except Granoleico, which is resistant. The regular and previously used cultivar Runner IAC 886 and breeding line L. 322 are resistant to the peanut red spider mite. [ABSTRACT FROM AUTHOR]

Plant parasitic root-knot nematodes (RKN) have evolved sophisticated strategies for exploiting plants, and they cause devastating yield losses in many susceptible crops. The RKN Meloidogyne arenaria is the most predominant pathogenic nematode affecting cultivated peanut (Arachis hypogaea L.). Resistance against the M. arenaria has been identified in the wild peanut relative, Arachis stenosperma. Transcriptome studies on A. stenosperma–M. arenaria interaction revealed candidate genes potentially involved in the first stages of this resistance response, including a temperature-induced lipocalin (TIL) protein. Plant TILs have a protective role against harmful molecules produced in response to a number of stresses. In this study, the characterization of the RKN-responsive TIL from A. stenosperma (AsTIL) provides new insights into the role of plant lipocalins in nematode resistance. The AsTIL gene has a 2-exon/1-intron structure and encodes a 21.4 kDa polypeptide. It contains three structurally conserved regions, which are a signature for plant lipocalins. Overexpression of AsTIL in transgenic hairy roots from a susceptible peanut cultivar led to the reduction of M. arenaria galls and egg masses 60 days after inoculation. This is the first report of a possible involvement of plant lipocalins in RKN resistance. It also reveals a promising candidate gene for peanut breeding to produce cultivars resistant to M. arenaria. [ABSTRACT FROM AUTHOR]

More than forty plant proteins have been associated with symbiotic N fixation, a process important for legume crop production. In peanut, rhizobia enter by more primitive root crack entry rather than through root hairs. To survey global changes in this system before nodule maturation, a whole-root proteome analysis was performed using 17-day-old wild-type and non-nodulating Arachis hypogaea. Tandem mass tag (TMT) six-plex labeling enabled simultaneous, LC-MS/MS comparison of triplicate samples, with and without Bradyrhizobium sp. inoculation. Using sequence from A. hypogaea diploid progenitors as a reference, >2000 protein families were identified per assay. Significant differences included a patatin-like protein with 2.62 and 14.52 fold higher abundance in uninoculated and inoculated roots of wild-type genotype E6+ compared to non-nodulating genotype E7-, respectively. A peroxidase and thaumatin-like protein recently identified by RNA-seq to have >2X transcript abundance in E6+ vs. E7- post-inoculation were similarly found in lower abundance in E7-. Conversely, aspartic proteinase and apoptosis-inducing factor family members were among proteins with higher abundance in uninoculated and inoculated E7-. Bradyrhizobium sp. peptides were generally in higher abundance in inoculated E6+, suggesting that early host-rhizobia interaction may be compromised in inoculated, non-nodulating E7-. Interestingly, many proteins with putative symbiotic roles identified in uninoculated wild-type and non-nodulating pairs (E4−/E5+ and E6+/E7-) were absent from 17-day-old, inoculated E6+ and E7-. The differentially represented proteins identified provide insight into the early stages of peanut nodulation. [ABSTRACT FROM AUTHOR]

NAC is one of the most abundant plant-specific groups of transcription factors, which play important roles in plant growth and development regulation, as well as in biotic and abiotic stress responses. In the present study, a stress-responsive NAC gene, AhNAC4, was isolated from a cDNA library of peanut ( Arachis hypogaea L.) immature seeds, and characterized for its role in drought tolerance. AhNAC4 shared high amino acid similarity with NAC proteins belonging to the ATAF subfamily. The expression analysis indicated that AhNAC4 was highly induced by drought, salinity and ABA treatments. Transient expression analysis showed the AhNAC4-GFP fusion protein was exclusively localized in the nucleus of onion epidermal cells. Transactivation assays in yeast cells demonstrated that AhNAC4 functioned as a transcription activator and its C-terminus contained the activation domain. Overexpression of AhNAC4 confers enhanced drought tolerance in transgenic tobacco plants. The improved drought tolerance was associated with more stomatal closure and higher water use efficiency. Collectively, our results indicated that AhNAC4 functions as an important regulator in response to drought stress. [ABSTRACT FROM AUTHOR]

Phosphoenolpyruvate carboxylase (PEPC) is a tightly controlled enzyme located at the core of plant carbohydrate metabolism. Plant PEPCs belong to a small multigene family encoding several plant-type PEPC genes, along with at least one distantly related bacterial-type PEPC gene. The PEPC genes have been intensively studied in Arabidopsis, but not in peanut (Arachis hypogaea L.). Previously, we isolated five PEPC genes ( AhPEPC1, AhPEPC2, AhPEPC3, AhPEPC4 and AhPEPC5) from peanut. Here, due to the sequencing of the peanut genome, we analyzed the complexity of its PEPC gene family, including phylogenetic relationships, gene structure and chromosome mapping. The results showed that AhPEPC1, AhPEPC2, AhPEPC3 and AhPEPC4 encoded typical plant-type enzymes, while AhPEPC5 was a bacterial-type PEPC. The recombinant proteins of these genes were expressed in Escherichia coli, and the calculated molecular weights of the recombinant proteins were 110.8 kD (AhPEPC1), 110.7 kD (AhPEPC2), 110.3 kD (AhPEPC3), 110.8 kD (AhPEPC4), and 116.4 kD (AhPEPC5). The expression patterns of AhPEPC1-5 were analyzed under cold, salt and drought conditions. Our results indicated that the expression of AhPEPC3 was rapidly and substantially enhanced under abiotic stress, whereas the expression of AhPEPC1 and AhPEPC2 was slightly enhanced under certain stress conditions. Some genes were down-regulated in leaves under stress: AhPEPC1, AhPEPC4 and AhPEPC5 under salt stress and AhPEPC4 and AhPEPC5 under drought stress. These results suggest that peanut PEPC proteins may differ in their functions during acclimation to abiotic stresses. [ABSTRACT FROM AUTHOR]

The effects of two water regimes (well-watered condition or drought stress) on root length, root surface area and root volume were tested on two peanut genotypes (the drought-resistant variety HuaYu 22 (HY22) and the drought-sensitive variety HuaYu 23 (HY23)), measured 101 days after sowing. The roots were sampled from the upper (0-40 cm) and deeper (40-100 cm) soil layers. Root diameter was measured to the nearest 0.5 mm in describing its distribution. Total dry weight and pod yield were measured at harvest. The drought tolerance index of pod yield and the harvest index in HY22 were higher than those in HY23. The total root length density (RLD), total root surface area and volume were significantly higher for HY22 than HY23. The RLD in the deeper soil layer was lower for HY23 than HY22. Under drought stress, the percent RLD in the deeper layers increased in both genotypes. Compared to well-watered condition, the total root surface area and root volume in the upper soil layer were lower under drought stress and root traits in deeper soil layers were higher. Drought stress had no impact on very fine roots (diameter < 0.5 mm) of HY22 in the deeper soil layer but lowered their share in HY23 markedly. The RLD and root surface area in the deeper soil layer were related to the pod yield of peanut. This finding could be useful in growing peanut under drought conditions. [ABSTRACT FROM AUTHOR]

Drought stress occurring at the seedling stage of peanut ( Arachis hypogaea L.) plants is a limiting factor resulting in considerable reductions in production. Plants can improve their resistance to subsequent stresses after experiencing an initial stress. The aim of this study was to explore the possible role of drought priming by hypocotyl exposure in alleviating subsequent severe drought stress in peanut. Hypocotyl exposure in peanut seedlings as a drought stimulus induced xerophytophysiological regulation, shown by induced osmotic adjustment, activated antioxidant enzymes, anthocyanin accumulation, up-regulation of Gdi- 15 and fewer amyloplasts. The seedlings primed by hypocotyl exposure showed improved leaf water retention and reduced proline content when exposed to subsequent drought stress. The alleviated oxidative damage and lower antioxidant enzyme activities indicated rapid acclimation following past hypocotyl exposure and further defenses against subsequent drought stress by retaining 'memories' to enable more rapid or stronger physiological responses. The improved leaf photosynthesis and low photosynthetic hysteresis as drought ended indicated a positive effect of drought priming in peanut seedlings. The peanut seedlings 'remembered' the xerophytophysiological responses caused by the prior drought stimulation from hypocotyl exposure and displayed quicker and more potent physiological responses to following drought stress. The results showed that hypocotyl exposure could help peanut seedlings survive the severe environments that occurred in the later growth stages. [ABSTRACT FROM AUTHOR]

Peanut seed oil is an important commodity worldwide and breeding efforts have been to improve both the quality and quantity of oil produced. Identifying sources of variation and elucidating the genetics of oil concentration and quality in peanut is essential to advancing the development of improved genotypes. The objective of this study was to discover QTLs for oil traits in an advanced backcross population derived from a cross between a wild-species derived amphidiploid, TxAG-6, and a cultivated genotype, Florunner. A BCF population was developed for genetic mapping and an advanced backcross BCF population was phenotyped in three environments and genotyped using SSR markers. Composite interval mapping results identified three genomic regions associated with oil concentration in a combined analysis. Marker PM36, associated with oil concentration and multiple fatty acids in this study, mapped directly to a HD-ZIP transcription factor in diploid Arachis genome sequences. For fatty acid concentrations, results suggested 17 QTLs identified in two or more environments, 15 of which were present across environments. Fourteen genomic regions on 13 linkage groups contained significant QTLs for more than one trait, suggesting that same genes or gene families are responsible for multiple phenotypes. QTLs and the genes identified in this study could be effective tools in marker-assisted breeding targeted at pyramiding seed oil alleles from wild-species while minimizing introgression of non-target chromatin. [ABSTRACT FROM AUTHOR]

Efficient and genotype-independent in vitro regeneration is an essential prerequisite for incremental trait improvement in peanut ( Arachis hypogaea L.) via genetic transformation. We have optimized a facile and rapid method to obtain direct shoot organogenesis from cotyledonary node (CN) explants excised from peanut seedlings germinated on cytokinin-supplemented Murashige and Skoog (MS) basal salt medium. Starting with mature embryos, shoot induction occurred in approximately 7 weeks, followed by 4 weeks for rooting of excised shoots and 3 weeks of acclimatization of regenerated plantlets in soil. The regeneration and transformation system described here is time-efficient, yielding greenhouse-acclimatized plantlets within 14 weeks, in contrast to 12-14 months required for initiating and regenerating somatic embryogenic cultures, currently the most tractable method available for peanut transformation. The highest shoot induction frequency and shoot quality was obtained with 6.66 μM 6-benzylaminopurine, followed by adequate root induction at 5.37 μM α-Naphthaleneacetic acid. New Mexican Valencia A was chosen for Agrobacterium-mediated transformation. Stable GUS expression from pWBvec10a was obtained at a transformation rate of 1.25 %. Furthermore, results from genomic PCR and Southern blot analyses showed that 14 out of 576 putative transgenic regenerants contained transgene pSag12::IPT, therefore yielding a total transformation rate of 2.43 %. The cotyledonary node-based direct regeneration system described here is time-efficient and amenable to Agrobacterium-mediated transformation, and therefore should be further explored for peanut transgenic improvement. [ABSTRACT FROM AUTHOR]

The feasibility of controlling peanut stem necrosis disease caused by Tobacco streak virus (TSV) in groundnut ( Arachis hypogaea L.) was explored by expressing double-stranded RNA of the replicase (Rep) gene of TSV in groundnut through genetic engineering. A hairpin (hp) RNAi construct containing 535-bp sense and antisense TSV- Rep sequences flanking a 742-bp spacer sequence (Pdk intron) under the control of the constitutive Cauliflower mosaic virus 35S promoter was made in the binary vector pART27. This chimeric gene construct was then mobilized into Agrobacterium tumefaciens strain LBA4404 via triparental mating using pRK2013 as a helper. Cotyledon explants of groundnut cultivar TMV-7 were transformed with A. tumefaciens harboring the hpRNA cassette. The presence of the transgene in the transgenic plants was confirmed up to T generation by PCR amplification of the 535-bp fragment of TSV- Rep gene. The bioassay results indicated that necrotic lesions were observed on the leaves of the wild-type plants 7-9 days after inoculation with TSV and stem necrosis appeared 16-20 days after inoculation, whereas the transgenic plants did not develop symptoms until harvest. ELISA results indicated that the wild-type plants inoculated with TSV recorded the highest virus concentration as compared to the transgenic lines. [ABSTRACT FROM AUTHOR]

The ability of inoculated rhizobial strains to increase root nodulation of host legumes often depends on their competitiveness with existing native soil strains. Results of studies to date on rhizobial inoculation for improvement of peanut ( Arachis hypogaea L.) production in Argentina have been inconsistent and controversial. In many cases, nodulation and yield of peanut crops have been increased by inoculation of specific rhizobial strains. Native peanut-nodulating strains are generally present in soils of agricultural areas, but their growth-promoting effect is often lower than that of inoculated strains. Many species of the genus Bradyrhizobium interact in a host-specific manner with legume species and form nitrogen-fixing root nodules. Other free-living rhizobacteria such as species of the genus Azospirillum are facultatively capable of interacting with legume roots and promoting plant growth. We evaluated and compared the effects of various single inoculation and co-inoculation treatments on peanut growth parameters in greenhouse and field experiments. In the greenhouse studies, co-inoculation with various Bradyrhizobium strains (native 15A and PC34, and recommended peanut inoculant C145), and Azospirillum brasilense strain Az39 generally resulted in increases in the measured parameters. The growth-promoting effect of 15A was similar to or higher than that of C145. In the field studies, 15A-Az39 co-inoculation had a greater promoting effect on measured growth parameters than did C145-Az39 co-inoculation. Our findings indicate that careful selection of native rhizobacterial strains adapted to peanut soils is useful in strategies for growth promotion, and that 15A in particular is a promising candidate for future inoculant formulation. [ABSTRACT FROM AUTHOR]

Field trials were conducted from 2006 to 2008 at the Tidewater Agricultural Research and Extension Center (TAREC) in Suffolk, Virginia to determine whether Blight Blocker transgenic peanut lines showed possible increased or decreased susceptibility to common peanut pathogens. Disease susceptibility was evaluated for seven transgenic lines containing a barley oxalate oxidase gene and their corresponding parental cultivars (Perry, Wilson, NC 7). In addition to Sclerotinia blight, the peanut diseases evaluated included: i) early leaf spot caused by Cercospora arachidicola, ii) Cylindrocladium black rot caused by Cylindrocladium parasiticum, iii) southern stem rot caused by Sclerotium rolfsii, iv) tomato spotted wilt virus, and v) aflatoxin levels in seeds caused by Aspergillus flavus or A. parasiticus. Results demonstrated that the susceptibility of Blight Blocker transgenic lines to common peanut pathogens was similar to that of non-transgenic cultivars, while transgenic lines provided resistance to Sclerotinia blight caused by S. minor. Transgenic lines consistently provided high levels of resistance to S. minor in all three years, however, the barley oxalate oxidase had little or no effect on the disease susceptibility to other organisms on peanut. The results of this research should provide additional evidence needed to petition for deregulation of Blight Blocker peanut lines. [ABSTRACT FROM AUTHOR]