Genome-Wide Association Study and Genomic Selection for Plant Growth Habit in Peanuts Using the USDA Public Data

Peanut (Arachis hypogaea L.) production is valued at $1.28 billion annually in the USA. Plant growth habit can be used to determine plant population density and cultivation practices a given farmer uses. Erect plants are generally more compact and can be more densely planted unlike plants with more prostrate growth. The objectives of this study were to analyze publicly available datasets to identify single-nucleotide polymorphism (SNP) markers associated with plant growth habit in peanuts and to conduct genomic selection. A genome-wide association study (GWAS) was used to identify SNPs for growth habit type among 775 USDA peanut accessions. A total of 13,306 SNPs were used to conduct GWAS using five statistical models. The models used were single-marker regression, generalized linear model (PCA), generalized linear model (Q), mixed linear model (PCA), and mixed linear model (Q) and a total of 181, 1, 108, 1, and 10 SNPs were found associated with growth habit respectively. Based on this dataset, results showed that genomic selection can achieve up to 61% accuracy, depending on the training population size being used for the prediction. SNP AX-176821681 was found in all models. Gene ontology for this location shows an annotated gene, Araip.0F3YM, found 2485 bp upstream of this SNP and encodes for a peptidyl-prolyl cis-trans isomerase. To the best of our knowledge, this is the first report identifying molecular markers linked to plant growth habit type in peanuts. This finding suggests that a molecular marker can be developed to identify specific plant growth habits in peanuts, enabling early generation selection by peanut breeders.

Estimation of Peanut Maturity Using Color Image Analysis

Peanuts pods grow underground and mature unevenly, resulting that choosing the correct time to harvest is more complicated than other crops. Pod maturity can be determined by blasting with a pressure washer to remove outer skin of the pod (exocarp) to expose the color of the middle layer (mesocarp). The mesocarp color changes with maturity from white to yellow, orange, brown and finally black. The sum of percentage from orange, brown, and black mesocarp (OBB) color and black color (BL) represents the kernels that are mature enough to harvest. The goal of this research is to identify methodologies to estimate OBB and BL of the pods using RGB images taken in the field and validate the proposed model using other pod images. The Mahalanobis distance classification method was used to process sets of images and calculate pod area (number of pixels) corresponding to two classes (mesocarp and background) with nine different color groups. The results showed a performance of 94% effectiveness for mesocarp using Mahalanobis distance classification. Statistical regression for OBB and BL was developed based on 315 images of peanut pods taken from the field. The R2 and root mean square error of predicted and actual OBB were 0.93 and 4.1%, respectively. The R2 and root mean square error of predicted and actual BL were 0.88 and 1.8%, respectively. The validation of OBB using other images provided reasonable estimation (R2 = 0.98 and RMSE = 2.73%). This study introduces a novel, cost-effective, and non-destructive method for estimating peanut maturity using RGB imagery and Mahalanobis distance classification in the field. This innovative approach addresses the limitations of traditional methods and offers a robust alternative for real-time maturity assessment.

Alternate cotton-peanut intercropping:a new approach to increasing productivity and minimizing environmental impact

Recent publications have highlighted the development of an alternate cotton-peanut intercropping as a novel strat-egy to enhance agricultural productivity.In this article,we provide an overview of the progress made in the alternate cotton-peanut intercropping,specifically focusing on its yield benefits,environmental impacts,and the underlying mechanisms.In addition,we advocate for future investigations into the selection or development of appropriate crop varieties and agricultural equipment,pest management options,and the mechanisms of root-canopy interactions.This review is intended to provide a valuable reference for understanding and adopting an alternate intercropping system for sustainable cotton production.

Magnesium fertilizer application increases peanut growth and pod yield under reduced nitrogen application in southern China

This study investigated the effect of magnesium application on peanut growth and yield under two nitrogen(N)application rates in acidic soil in southern China.The chlorophyll content,net photosynthetic rate and dry matter accumulation of the N-sensitive cultivar decreased under reduced N treatments,whereas no effect was observed on the relevant indicators in the N-insensitive variety GH1026.Mg application increased the net photosynthetic rate by increasing the expression of genes involved in chlorophyll synthesis and Rubisco activity in the leaves during the pegging stage under 50%N treatment,while no effect on the net photosynthetic rate was observed under the 100%N treatment.The rate of dry matter accumulation at the early growth stage,total dry matter accumulation and pod yield at harvest increased after Mg application under 50%N treatment by increasing the transportation of assimilates from stems and leaves to pods in both peanut varieties,whereas no effect was found under 100%N treatment.Moreover,Mg application increased the NUE under 50%N treatment.No improvement of NUE in either peanut variety was found under 100%N treatment,while Mg application under the 50%N treatment can obtain a higher economic benefit than the 100%N treatment.In acidic soil,application of 307.5 kg ha^(-1)of Mg sulfate fertilizer under 50%reduced nitrogen application is a suitable fertilizer management measure for improving carbon assimilation,NUE and achieve high peanut yields in southern China.

Profile of Peanut Sensitization in Children Attending a Pneumo-Allergology Consultation at the Teaching Hospital Campus of Lomé, Togo

Introduction: Food allergies are on the constant increase worldwide. Among them is peanut allergy, which also affects children. The aim of this study was to determine the profile of peanut sensitization in children attending a pneumo-allergology consultation. Methods: This was a cross-sectional study, which ran from January 1, 2018, to December 31, 2022, on children sensitized to peanuts seen in pneumo-allergology consultations at the Teaching Hospital Campus of Lomé. Results: The sample included 137 children aged 3 months to 18 years. The frequency of peanut sensitization was 25.3%. The mean age of patients was 6.3 ± 4.3 years (minimum 6 months and maximum 18 years). The 6 months to 5 years age group was the most represented (43.1%). The sex ratio was 1.3. The main reasons for consultation were rhinorrhea (67.9%), sneezing (36.5%) and cough (35.8%). Allergic rhinitis was identified as a personal history in 75.2% of patients. Peanut allergy was manifested as rhinorrhea (62.5%), asthma (26.8%) and eczema (8.9%). The risk of onset of symptoms within 15 - 30 minutes was 1.87 times (p = 0.001, CI = [1.2 - 2.1]) for peanuts consumed in roasted form with shell. Severe clinical signs such as Quincke’s Edema and anaphylactic shock were found in 1.4% of cases. Conclusion: Peanut allergy was common in children. Severe clinical signs were rare.

Contribution to the Study of Fungal Strains Contaminating Peanut Pastes in Bangui (Central African Republic)

Introduction: Peanut pastes are food products resulting from artisanal or industrial processing, used in cooking in Africa in general and in Central African Republic in particular. These peanut pastes are often contaminated by molds and filamentous fungi involved in the degradation of hygienic and organoleptic or even toxicological quality. This study aims to determine the epidemiological profile of molds contaminating peanut pastes sold on the Central African market. Methodology: This was a cross-sectional study carried out from June to September 2023. Samples of peanut pastes sold on Central African market were taken and analyzed at the National Laboratory of Clinical Biology and Public Health using the conventional microbiology method according to ISO 7954 standards. The data obtained were collected in the ODK 2023.3.1 application and analyzed with the Epi Info 7 software. A multivariate analysis by logistic regression, Ficher’s exact test, and chi2 at the 5% threshold (p Penicillium sp.;11.25% of Mucor sp.;10.63% of Aspergillus terrei;3.13% of Aspergillus niger;1.25% of Aspergillus medullans;28.13% of Aspergillus flavus;2.50% of Aspergillus fumigatus. Peanut pastes stored beyond three days were more contaminated (94.19%). Conclusion: The results of this study made it possible to highlight strains of mold that impact the hygienic and organoleptic quality of peanut pastes sold at the Central African market. Most of the isolated strains were the Aspergillus flavus species which is recognized by its toxigenic effects. This species is much more incriminated in the contamination of foodstuffs with the production of the toxin which causes underlying pulmonary pathologies in humans.

Diet with high content of advanced glycation end products induces oxidative stress damage and systemic inflammation in experimental mice: protective effect of peanut skin procyanidins

Non-enzymatic glycation reaction in food can produce diet-derived advanced glycation end products(dAGEs),which have potential health risks.Thus,it is of great significance to find efficient substances to improve the negative effects induced by dAGEs on human health.This study investigated the intervening effects of peanut skin procyanidins(PSP)on the dAGEs-induced oxidative stress and systemic inflammation in experimental mice model.Results showed that the accumulation of AGEs in serum,liver,and kidney was significantly increased after mice were fed dAGEs(P<0.05).The expression of advanced glycation product receptor(RAGE)was also significantly increased in liver and kidney(P<0.05).PSP could not only effectively reduce the accumulation of AGEs in serum,liver and kidney of mice,but also reduce the expression of RAGE in liver and kidney of mice.And the levels of pro-inflammatory cytokines interleukin-6(IL-6),tumor necrosis factor(TNF-α),and IL-1βin serum of mice were significantly decreased(P<0.05),while the levels of antiinflammatory factor IL-10 were increased,and the inflammatory injury in mice was improved.In addition,the levels of superoxide dismutase(SOD),glutathione(GSH),catalase(CAT)in liver and kidney of mice were increased(P<0.05),and the level of malondialdehyde(MDA)was decreased(P<0.05),which enhanced the antioxidant capacity of mice in vivo,and improved the oxidative damage of liver and kidney.Molecular docking technique was used to confirm that the parent compound of procyanidins and its main metabolites,such as 3-hydroxyphenylacetic acid,could interact with RAGE,which might inhibit the activation of nuclear transcription factor(NF-κB),and ultimately reduce oxidative stress and inflammation in mice.

Mass transfer process of peanut protein extracted by bis(2-ethylhexyl)sodium sulfosuccinate reverse micelles

The liquid-liquid extraction method using reverse micelles can simultaneously extract lipid and protein of oilseeds,which have become increasingly popular in recent years.However,there are few studies on mass transfer processes and models,which are helpful to better control the extraction process of oils and proteins.In this paper,mass transfer process of peanut protein extracted by bis(2-ethylhexyl)sodium sulfosuccinate(AOT)/isooctane reverse micelles was investigated.The effects of stirring speed(0,70,140,and 210 r/min),temperature of extraction(30,35,40,45,and 50℃),peanut flour particle size(0.355,0.450,0.600,and 0.900 mm)and solidliquid ratio(0.010,0.0125,0.015,0.0175,and 0.020 g/mL)on extraction rate were examined.The results showed that extraction rate increased with temperature rising,particle size reduction as well as solid-liquid ratio increase respectively,while little effect of stirring speed(P>0.05)was observed.The apparent activation energy of extraction process was calculated as 10.02 kJ/mol and Arrhenius constant(A)was 1.91 by Arrhenius equation.There was a linear relationship between reaction rate constant and the square of the inverse of initial particle radius(1/r_(0)^(2))(P<0.05).This phenomenon and this shrinking core model were anastomosed.In brief,the extraction process was controlled by the diffusion of protein from the virgin zone interface of particle through the reacted zone and it was in line with the first order reaction.Mass transfer kinetics of peanut protein extracted by reverse micelles was established and it was verified by experimental results.The results provide an important theoretical guidance for industrial production of peanut protein separation and purification.

Low-fat microwaved peanut snacks production:Effect of defatting treatment on structural characteristics,texture,color,and nutrition

This study develops low-fat microwaved peanut snacks(LMPS)using partially defatted peanuts(PDP)with different defatting ratios,catering to people’s pursuit of healthy,low-fat cuisine.The effects of defatting treatment on the structural characteristics,texture,color,and nutrient composition of LMPS were comprehensively explored.The structural characteristics of LMPS were characterized using X-ray micro-computed tomography(Micro-CT)and scanning electron microscope(SEM).The results demonstrated that the porosity,pore number,pore volume,brightness,brittleness,protein content,and total sugar content of LMPS all significantly increased(P<0.05)with the increase in the defatting ratio.At the micro level,porous structure,cell wall rupture,and loss of intracellular material could be observed in LMPS after defatting treatments.LMPS made from PDP with a defatting ratio of 64.44%had the highest internal pore structural parameters(porosity 59%,pore number 85.3×10^(5),pore volume 68.23 mm3),the brightest color(L^(*) 78.39±0.39),the best brittleness(3.64±0.21)mm^(–1)),and the best nutrition(high protein content,(34.02±0.38)%;high total sugar content,(17.45±0.59)%;low-fat content,(27.58±0.85)%).The study provides a theoretical basis for the quality improvement of LMPS.

Breeding and Application of Red-skinned Yun Peanut No.3

[Objective] The aim was to explore the production potential and extension value of Yun peanut No.3 to lay foundation for further extension. [Method] Selection, breeding, characters, yield and the stability of Yun peanut No.3 were analyzed. [Result] Yun peanut No.3 is a new early-mature peanut species bred based on foreign resources and local varieties through sexual hybridization and improvement. It contains 50.32% of fat, 26.5% of protein, 38.93% of oleic acid, 38.88% of linoleic acid, and the ratio of oleic acid and linoleic acid is at 1.00. It is a typical small-scale peanut with red skin, high contents of oil and fat, and constitutes the first one approved by cultivar registration in China. According to related tests, pod yield achieved 3 615.9 kg/hm2 ; kernel yield was 2 570.1 kg/hm2 and oil output was 1 293.3 kg/hm2 . For the production at scale, pod yields would be about 3 000 kg/hm2 ; the production value of fruit would be 25 000 Yuan/hm2 ; the yield per unit area would be maximal at 16 000 kg/hm2 , totaling 64 000 Yuan/hm2 . It enjoys different excellent qualities, such as drought-resistance and barren-resistance. It was approved in Yunnan Province in 2012 and extended at 20 000 Yuan/hm2 in major production lands. [Conclusion] Yun peanut No.3, which is highly-yield and highly-qualified, is suitable to be grown in Yunnan, as well as similar conditions in southern regions in China.

Development of Oligo-GISH kits for efficient detection of chromosomal variants in peanut

Oligo probe staining is a low-cost and efficient chromosome identification technique.In this study,oligo genomic in situ hybridization(Oligo-GISH)technology was established in peanut.Peanut A and B subgenome-specific interspersed repeat(IR)oligo probe sets were developed based on clustering and electronic localization of tandem repeat sequences in the reference genome of Tifrunner.The OligoGISH kit was then used to perform staining of 15 Arachis species.The A-subgenome probe set stained the chromosomes of A-and E-genome Arachis species,the B-subgenome probe set stained those of B-,F-,K-,and E-genome species,and neither set stained those of H-genome species.These results indicate the relationships among the genomes of these Arachis species.The Oligo-GISH kit was also used for batch staining of the chromosomes of 389 seedlings from the irradiated M1generation,allowing 67 translocation and deletion lines to be identified.Subsequent Oligo-FISH karyotyping,FISH using single-copy probe libraries,and trait investigation identified seven homozygous chromosomal variants from the M3generation and suggested that there may be genes on chromosome 4B controlling seed number per pod.These findings demonstrate that the IR probe sets and method developed in this study can facilitate research on distant hybridization and genetic improvement in peanut.

Effects of Allelochemicals on Root Growth and Pod Yield in Response to Continuous Cropping Obstacle of Peanut

Continuous cropping(CC)obstacle is a major threat in legume crops production;however,the underlying mechanisms concerning the roles allelochemicals play in CC obstacle are poorly understood.The current 2-year study was conducted to investigate the effects of different kinds and concentrations of allelochemicals,p-hydroxybenzoic acid(H),cinnamic acid(C),phthalic acid(P),and their mixtures(M)on peanut root growth and productivity in response to CC obstacle.Treatment with H,C,P,and M significantly decreased the plant height,dry weight of the leaves and stems,number of branches,and length of the lateral stem compared with control.Exogenous application of H,C,P,and M inhibited the peanut root growth as indicated by the decreased root morphological characters.The allelochemicals also induced the cell membrane oxidation even though the antioxidant enzymes activities were significantly increased in peanut roots.Meanwhile,treatment with H,C,P,and M reduced the contents of total soluble sugar and total soluble protein.Analysis of ATPase activity,nitrate reductase activity,and root system activity revealed that the inhibition effects of allelochemicals on peanut roots might be due to the decrease in activities of ATPase and NR,and the inhibition of root system.Consequently,allelochemicals significantly decreased the pod yield of peanut compared with control.Our results demonstrate that allelochemicals play a dominant role in CC obstacle-induced peanut growth inhibition and yield reduction through damaging the root antioxidant system,unbalancing the osmolytes accumulation,and decreasing the activities of root-related enzymes.

Correlation and variability analysis of yield and quality related traits in different peanut varieties across various ecological zones of China

Peanut cultivation in China spans various ecological zones, each with unique environmental conditions. Identifying suitable peanut varieties for these regions has been challenging due to significant phenotypic variations observed across environments. This study, based on a comprehensive analysis of 256 peanut varieties, selected nine representative varieties(Huayu23, Yuanza9102, Silihong, Wanhua2, Zhonghua6, Zhonghua16, Zhonghua21,Zhonghua215, Zhonghua24) for cultivation in five distinct ecological zones including Chengdu, Hefei, Nanjing,Shijiazhuang, and Wuhan. The yield and quality related phenotypic traits of these varieties were thoroughly assessed, revealing a complex interplay between genetic and environmental factors. Principal component analysis(PCA) effectively distinguished varieties based on yield and quality traits. Strong correlations were observed between specific traits, such as seed size and quality components. The G × E interaction was evident, as some varieties consistently performed better in certain environments. Varieties with lower coefficient of variation(CV)values exhibited stable trait expression, making them reliable choices for broad cultivation. In contrast, varieties with higher CV values displayed greater sensitivity to environmental fluctuations, potentially due to specific genetic factors. Two high oleic acid varieties, Zhonghua24 and Zhonghua215, demonstrated remarkable stability in oleic acid content across diverse environments, suggesting the presence of genetic mechanisms that buffer against environmental variations. Overall, this study underscores the importance of selecting peanut varieties based on their adaptability and performance in specific ecological zones. These findings provide valuable insights for peanut breeders and farmers, facilitating informed decisions for improved crop production and quality.

Evaluation of allergenic protein profiles in three Chinese high-oleic acid peanut cultivars using NanoLC-Orbitrap mass spectrometry

High oleic-acid peanuts are known for their pre-longed shelf-life and health benefit due to high content of oleic fatty acid.However,the allergenicity and allergenic protein profiles in Chinese high-oleic peanuts have yet to be studied.For this purpose,an Orbitrap Fusion mass spectrometry(MS)-based method that is feasible for identification of putative allergenic protein as well as semi-quantitation of five major allergen protein in three different Chinese high-oleic peanut cultivars(JH 13,JH 16 and JH 18)have been reported.Results show that three Chinese high-oleic acid peanut cultivars selected all contained highly allergenic proteins Ara h1,Ara h 2,Ara h 3 and Ara h 6.The allergenic protein profiles of Chinese high-oleic acid peanut cultivars were very similar to that of conventional peanuts,but the allergenic protein subunits varied greatly among higholeic peanuts.Additionally,a comprehensive peptide-filtering pipeline had been developed for identification of potential peptide markers in peanut allergen proteins.Through the peptide-filtering pipeline,three novel peptide markers,IVQIEAKPNTLVLPK,SSNPDIYNPQAGSLR and AQSENYEYLAFK surrogate to Ara h 1,Ara h 3 with high abundance,good MS response and highly reliability were identified,which can be used as candidate peptide markers for the detection of peanut allergens in different food matrices.

Study on mechanism of increased allergenicity induced by Ara h 3 from roasted peanut using bone marrow-derived dendritic cells

Little information was so far available about allergenic mechanism of the roasted peanut allergens during initial stages of allergy.The purpose of this study was to determine the influence of roasting(150℃,20 min)on biochemical and biological properties of Ara h 3,a major peanut allergen.Allergenicity of roasted peanut emulsion to mice,differences in uptakes between Ara h 3 purified from raw peanuts(named as Ara h 3-Raw)and that purified from roasted peanuts(named as Ara h 3-Roasted)by bone marrow-derived dendritic cells(BMDCs)and the implication of cell surface receptors involving in uptake,and changes in glycosylation and structure of Ara h 3 after roasting were analyzed in this study.This study suggested that roasting increased allergenicity of peanut to BALB/c mice.Maillard reaction and structural changes of Ara h 3 induced by roasting significantly altered the uptake of Ara h 3-Roasted by BMDCs,and modified Ara h 3 fate in processes involved in immunogenicity and hyper allergenicity,indicating that food processing pattern can change food allergenicity.

Use of Unmanned Aerial System (UAS) Phenotyping to Predict Pod and Seed Yield in Organic Peanuts

Peanut (Arachis hypogaea L.) is a highly nutritious food that is an excellent source of protein and is associated with increased coronary health, lower risk of type-2 diabetes, lower risk of breast cancer and a healthy profile of inflammatory biomarkers. The domestic demand for organic peanuts has significantly increased, requiring new breeding efforts to develop peanut varieties adapted to the organic farming system. The use of unmanned aerial system (UAS) has gained scientific attention because of the ability to generate high-throughput phenotypic data. However, it has not been fully investigated for phenotyping agronomic traits of organic peanuts. Peanuts are beneficial for cardio system protection and are widely used. Within the U.S., peanuts are grown in 11 states on roughly 600,000 hectares and averaging 4500 kg/ha. This study’s objective was to test the accuracy of UAS data in the phenotyping pod and seed yield of organic peanuts. UAS data was collected from a field plot with 20 Spanish peanut breeding lines on July 07, 2021 and September 27, 2021. The study was a randomized complete block design (RCBD) with 3 blocks. Twenty-five vegetation indices (VIs) were calculated. The analysis of variance showed significant genotypic effects on all 25 vegetation indices for both flights (p < 0.05). The vegetation index Red edge (RE) from the first flight was the most significantly correlated with both pod (r = 0.44) and seed yield (r = 0.64). These results can be used to further advance organic peanut breeding efforts with high-throughput data collection.

Millet/peanut intercropping at a moderate N rate increases crop productivity and N use efficiency,as well as economic benefits,under rain-fed conditions

Cereal and legume intercropping has been widely adopted to increase crop productivity in sustainable farming systems worldwide.Among different intercropping combinations,millet and peanut intercropping can be adapted to most waterlimited areas.However,there are few studies on the differences in yield characteristics and nitrogen use efficiency between millet/peanut intercropping and monocultures under different nitrogen (N) application rates.The objective of this study was to determine the yield advantages and economic benefits,as well as the appropriate N application rate,of millet/peanut intercropping.A two-yearfield experiment was conducted with three cropping patterns (monoculture millet,monoculture peanut and millet/peanut intercropping) and four N rates (0,75,150 and 225 kg ha^(-1)).The results showed that the land equivalent ratio (LER) and net effect (NE) of the intercropping system reached their highest levels at the N input of 150 kg ha^(-1)in 2018 and 2019 (1.04 for LER,0.347 Mg ha^(-1)for NE,averaged across two years).Millet was the dominant crop in the intercropping system (aggressivity of millet and peanut (Amp)>0,competitive ratio of millet and peanut (CRmp)>1),and millet yields achieved their highest values at N inputs of 225 kg ha^(-1)for monoculture and 150 kg ha^(-1)for intercropping.NUE reached its highest levels with N inputs of 150 kg ha^(-1)for all planting patterns over the two years.Intercropping combined with an N input of 150 kg ha^(-1)achieved the highest net income of 2 791 USD ha^(-1),with a benefit-cost ratio of 1.56,averaged over the two years.From the perspective of economics and agricultural sustainable development,millet/peanut intercropping at 150 kg N ha^(-1)seems to be a promising alternative to millet or peanut monoculture.

A stable and major QTL region on chromosome 2 conditions pod shape in cultivated peanut(Arachis hyopgaea L.)

Peanut pod shape is a heritable trait which affects the market acceptance of in-shell peanut products.In order to determine the genetic control of pod shape,six component traits of pod shape(pod length,pod width,pod length/width ratio,pod roundness,beak degree and constriction degree)were measured using an image-based phenotyping method.A recombinant inbred line(RIL)population consisting of 181 lines was phenotyped across three environments.Continuous distributions and transgressive segregations were demonstrated in all measured traits and environments.Significant correlations were found among most component traits with broad-sense heritability ranging from 0.87 to 0.95.Quantitative trait locus(QTL)analysis yielded 26 additive QTLs explaining 3.79 to 52.37%phenotypic variations.A novel,stable and major QTL region conditioning multiple shape features was detected on chromosome 2,which spans a 10.81-Mb genomic region with 543 putative genes.Bioinformatics analysis revealed several candidate genes in this region.In addition,73 pairs of epistatic interactions involving 92 loci were identified for six component traits explaining 0.94–6.45%phenotypic variations.These results provide new genetic loci to facilitate genomics-assisted breeding of peanut pod shape.

Evaluation of Beta-Lactam Antibiotics on the Regeneration of Peanut Plants and Their Inhibitory Effect on Agrobacterium Growth

The effect of beta-lactam antibiotics on shoot induction and plantlet regeneration from cotyledonary nodes was tested using two peanut cultivars.The culture media contained 4 mg/L 6-benzylaminopurine(BAP)as the main growth regulator.Various concentrations(100–600 mg/L)of cefotaxime,carbenicillin,and timentin were applied in the culture media.In all the tested media,there were no significant differences in the shoot induction as compared to the control.However,little phytotoxic effect was observed at higher concentrations of these antibiotics in the shoot elongation media.Under shoot elongation medium,shoots turned brownish and partly died at higher concentrations where shooting rates were not affected by the treatments.In cefotaxime,timentin,and carbenicillin-containing media,levels of antibiotics greater than 400,300,and 200 mg/L,respectively resulted in the brown coloration of plantlets.Moreover,the mean shoot number and shoot weight significantly decreased as their dosage increased.The results indicate that maximum levels of antibiotics have an adverse effect on the growth and development of peanuts.Also,cefotaxime(100–300 mg/L)and timentin(100–300 mg/L)will be sufficient in controlling Agrobacterium growth in the culture media with the least phytotoxic effect on the peanut plants.

Construction of EMS-Induced Peanut Mutant Libraries and Identification of Pod-Related Traits Mutant Lines

Peanut(Arachis hypogaea L.)is an oil and economic crop of vital importance,and peanut pod is the key organ influencing the yield and processing quality.Hence,the Pod-related traits(PRTs)are considered as important agronomic traits in peanut breeding.To broaden the variability of PRTs in current peanut germplasms,three elite peanut cultivars were used to construct Ethyl methane sulfonate(EMS)-induced mutant libraries in this study.The optimal EMS treatment conditions for the three peanut varieties were determined.It was found that the median lethal dose(LD50)of EMS treatment varied greatly among different genotypes.Finally,the EMS-induced peanut mutant libraries were constructed and a total of 124 mutant lines for PRTs were identified and evaluated.Furthermore,“M-8070”,one of the mutant lines for pod constriction,was re-sequenced via high-throughput sequencing technology.The genome-wide variations between“M-8070”and its wild parent“Fuhua 8”(FH 8)were detected.2994 EMS-induced single nucleotide polymorphisms(SNPs)and 1188 insertion-deletions(InDels)between“M-8070”and its wild parent were identified.The predominant SNP mutation type was C/G to T/A transitions,while the predominant InDel mutation type was“1-bp”.We analyzed the distribution of identified mutations and annotated their functions.Most of the mutations(91.68%of the SNPs and 77.69%of the InDels)were located in the intergenic region.72 SNPs were identified in the exonic region,leading to 27 synonymous,43 nonsynonymous and 2 stop-gain variation for gene structure.13 Indels were identified in the exonic region,leading to 4 frame-shift,8 non-frame-shift and 1 stop-gain variations of genes.These mutations may lead to the phenotypic variation of“M-8070”.Our study provided valuable resources for peanut improvement and functional genomic research.