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.

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.

Peanuts and Their Nutritional Aspects—A Review

Peanut is a legume crop that belongs to the family of Fabaceae, genus Arachis, and botanically named as Arachis hypogaea. Peanuts are consumed in many forms such as boiled peanuts, peanut oil, peanut butter, roasted peanuts, and added peanut meal in snack food, energy bars and candies. Peanuts are considered as a vital source of nutrients. Nutrition plays an important role in growth and energy gain of living organisms. Peanuts are rich in calories and contain many nutrients, minerals, antioxidants, and vitamins that are essential for optimum health. All these biomolecules are essential for pumping vital nutrients into the human body for sustaining normal health. This paper presents an overview of the peanut composition in terms of the constituent biomolecules, and their biological functions. This paper also discusses about the relationship between consumption of peanuts and their effect on human metabolism and physiology. It highlights the usefulness of considering peanuts as an essential component in human diet considering its nutritional values.

Sensing of Moisture Content of In-Shell Peanuts by NIR Reflectance Spectroscopy

It was found earlier that moisture content (MC) of intact kernels of grain and nuts could be determined by Near Infra Red (NIR) reflectance spectrometry. However, if the MC values can be determined while the nuts are in their shells, it would save lot of labor and money spent in shelling and cleaning the nuts. Grain and nuts absorb low levels of NIR, and when NIR radiation is incident on them, a substantial portion of the radiation is reflected back. Thus, studying the NIR reflectance spectra emanating from in-shell peanuts, an attempt is made for the first time to determine the MC of in-shell peanuts. In-shell peanuts of two different market types, Virginia and Valencia, were conditioned to different moisture levels between 6% and 26% (wet basis), and separated into calibration and validation groups. NIR absorption spectral data from 1000 nm to 2500 nm in 1 nm intervals were collected from both groups. Measurements were obtained on 30 replicates within each moisture level. Reference MC values for each moisture level in these groups were obtained using standard air-oven method. Partial Least Square (PLS) analysis was performed on the calibration data, and prediction models were developed. The Standard Error of Calibration (SEC), and R2 of the calibration models were computed to select the best calibration model. The selected models were used to predict the moisture content of peanuts in the validation sets. Predicted MC values of the validation samples were compared with their standard air-oven moisture values. Goodness of fit was determined based on the lowest Standard Error of Prediction (SEP) and highest R2 value obtained for the prediction models. The model, with reflectance plus normalization spectral data with an SEP of 0.74 for Valencia and 1.57 for Virginia type in-shell peanuts was selected as the best model. The corresponding R2 values were 0.98 for both peanut types. This work establishes the possibility of sensing MC of intact in-shell peanuts by NIR reflectance method, and would be useful for the peanut and allied industries.

Health aspects of peanuts as an outcome of its chemical composition

Peanut is an energy dense food item and it contains a substantial amount of fat,proteins,carbohydrate,both fat soluble and water soluble vitamins,minerals and phytochemicals.Peanuts are consumed worldwide due to its high nutritional value and pleasant or unique flavor after roasting or boiling.The lipid,protein and carbohydrate not only provide energy,but also provide essential nutrients for normal body functions such as body fat and muscle buildup.Vitamins are needed for normal cell function,growth,development,disease prevention and act as coenzymes during the production of energy.Due to the high nutrient contents of peanuts,they have been used to combat malnutrition in most developing countries.Epidemiologic studies have associated nut consumption with a reduced incidence of cardiovascular heart diseases and gallstones in both genders and diabetes in women.Limited evidence also suggests beneficial effects on hypertension,cancer,and inflammation.The health risk associated with peanut consumption is allergy in developed countries.The review discusses the health aspects,including allergy,of peanut consumption as they related to the chemical composition of peanuts using literatures published in past two decades with exceptions of a few older articles.

Population structure and association mapping to detect QTL controlling tomato spotted wilt virus resistance in cultivated peanuts

Tomato spotted wilt(TSW)is a serious virus disease of peanut in the United States.Breeding for TSWV resistance would be facilitated by the implementation of marker-assisted selection in breeding programs;however,genes associated with resistance have not been identified.Association mapping is a type of genetic mapping that can exploit relationships between markers and traits in many lineages.The objectives of this study were to examine genetic diversity and population structure in the U.S.peanut mini-core collection using simple sequence repeat(SSR)markers,and to conduct association mapping between SSR markers and TSWV resistance in cultivated peanuts.One hundred and thirty-three SSR markers were used for genotyping 104 accessions.Four subpopulations,generally corresponding to botanical varieties,were classified by population structure analysis.Association mapping analysis indicated that five markers:pP GPseq5D5,GM1135,GM1991,TC23C08,and TC24C06,were consistently associated with TSW resistance by the Q,PCA,Q+K,and PCA+K models.These markers together explained 36.4%of the phenotypic variance.Moreover,pP GPseq5D5 and GM1991 were associated with both visual symptoms of TSWV and ELISA values with a high R^2.The potential of these markers for use in a marker-assisted selection program to breed peanut for resistance to TSWV is discussed.

Nitrogen Dioxide Fumigation for Microbial Control on Unshelled Peanuts*

Stored peanuts often need treatments to control microbial infections as well as insects to maintain postharvest quality. Nitric oxide (NO) is a recently discovered fumigant for postharvest pest control. NO fumigation must be conducted under ultralow oxygen condition to preserve NO and always contains NO2 due to NO reaction with oxygen and NO2 has antimicrobial property. Therefore, NO fumigation has potential to control both pests and pathogens. In this study, we evaluated antimicrobial effects of NO2 fumigation on unpasteurized unshelled peanuts. Peanuts were fumigated with 0.3%, 1.0%, and 3.0% NO2 for three days at 25˚C by injecting NO gas into glass jars to react with O2 in the atmosphere. After fumigation, wash-off microbial samples were collected from intact peanut samples and, then, cracked open peanut samples with non-selective tryptic soy broth medium. The wash-off samples were then diluted with both the non-selective medium and a fungal-selective potato dextrose broth medium and were tested on GreenLight™ rapid enumeration test based on oxygen depletion on culture medium. All three NO2 fumigation treatments showed significant antibacterial and antifungal effects on intact peanuts as well as on cracked peanuts with complete inhibition with 3.0% NO2. Fumigation did not have obvious effects on appearance of skinned peanut kernels. These results suggested that NO2 fumigation has potential to control microbes on stored products, and NO fumigation with the combination of NO and NO2 has potential to control both insects and microbes on stored products.

Occurrence of <i>Aspergillus</i>Species and Aflatoxin Contamination in Raw and Roasted Peanuts from Formal and Informal Markets in Eldoret and Kericho Towns, Kenya

The population and diversity of fungal species and levels of aflatoxin contamination were investigated in 228 marketed peanut samples;140 from formal and 88 from informal markets, in Kericho and Eldoret towns of Kenya. Ground peanut samples were cultured on Modified Dichloran Rose Bengal (MDRB) agar while aflatoxin level was quantified based on indirect competitive ELISA. Correlation between the incidence of major aflatoxin-producing fungal species and aflatoxin levels was also established. Fungal species commonly isolated from the peanut samples included Aspergillus flavus L strain, A. flavus S strain, A. parasiticus, A. tamarii, A. caelatus, A. alliaceus (all of Aspergillus section Flavi) and A. niger. Fungi isolated in low frequency included Fusarium spp., Penicillium spp., Mucor spp. and Rhizopus spp. Aflatoxin levels in peanut products ranged from 0 to 2345 μg/kg in raw peanuts, 0 to 382 μg/kg in roasted coated peanuts, and 0 to 201 μg/kg in roasted de-coated peanuts. Overall, levels of total aflatoxin were higher in samples from informal (mean = 97.1 μg/kg) than formal (mean = 55.5 μg/kg) market outlets. There was a positive and significant correlation (R2 = 0.63;p ≤ 0.05) between aflatoxin levels and the major aflatoxin producing fungi in raw peanuts from formal markets in Eldoret town. Additionally, total aflatoxin in raw peanut samples from informal markets in Kericho was positively and significantly correlated (R2 = 0.81;p ≤ 0.05) to the population of A. flavus (L and S strains). In roasted coated peanuts sampled from formal market outlets in Eldoret, aflatoxin levels correlated positively and significantly (R2 = 0.37;p ≤ 0.05) with A. flavus S strain. There is need to create awareness among peanut traders and consumers on proper handling of peanuts and health risks associated with consumption of unsafe peanut products.

Incidence, Types and Levels of Aflatoxin in Different Peanuts Varieties Produced in Busia and Kisii Central Districts, Kenya

Busia and Kisii Central districts are areas in western Kenya that have repeatedly reported high levels of stunting growth in children and an increase in hepatocellular carcinoma (HCC);an aspect often positively associated with chronic exposure to aflatoxins especially through consumption of foods such as peanuts. The objectives of the study were to determine the incidence, types and levels of aflatoxin in different varieties of peanuts produced in Busia and Kisii Central districts. One hundred and two (102) peanuts samples were collected from farmers’ in each district. Aflatoxin types and levels of aflatoxins were analyzed using high performance liquid chromatography (HPLC) technique. All the peanuts samples from Kisii Central and 97.06% samples from Busia were contaminated with aflatoxins. However, aflatoxin was not detected in 2.94% of samples from Busia district. The levels of total aflatoxin ranges were 0.1 to 268 μg/kg and 1.63 to 591.1 μg/kg in peanuts from Busia and Kisii Central respectively. Majority of peanuts samples had levels within Kenya Bureau of Standards (KEBS) and European Union (EU) regulatory limits for total aflatoxins. Improved variety (Valencia red) had significantly lower aflatoxin contamination compared to local varieties (Uganda local red, Homabay local and Local red). Aflatoxins B1, B2, G1 and G2 were found in peanuts;B1 was the most predominant in both districts (t = 12.4, df = 3, P = 0.034). The levels of aflatoxins especially in peanuts from Kisii Central district were high (591.1 μg/kg) where 44.6% of samples analyzed were unfit for even animal feed (USFDA regulatory limit). An assessment on the levels of aflatoxins should be done by the relevant stakeholders in other key foods in the areas for example maize. The most lethal aflatoxin type B1 was found to be the most predominant peanuts from both districts of study. This calls for frequent aflatoxin screening of peanuts from the districts particularly aflatoxin type B.

HSUJI,KINUS,Quality and Reputation Symbol of Shandong Peanuts

It is a fully 100 years sinceShandong started exportingpeanuts. In 1958,the ShandongCereals and Oils Branch of theChina National Cereals,Oils andFoodstuffs Import and ExportCorporation,specializing in theexport of peanuts,startedprocessing peanuts.In 1960,the branch began setting uppeanut export bases,and in 1964,it shifted the main focus of itsexports to Western Europe.In1966,the branch gave acommodity name to its newlydeveloped peanuts,HSUJI,Shandong has since then exportedits peanuts under their own name.

Potential for Control of A.Flavus and Aflatoxin B_(1)in Vitro and in Stored Egyptian Shelled Peanuts using Gaseous Ozone Treatment

The objective of this study was to examine the effect of gaseous ozone(O_(3))on(a)germination,(b)mycelial growth,(c)aflatoxin B1(AFB1)production by strains of Aspergillus flavus at different water activity(aw,0.89~0.97=13.1%~24%moisture content)and 25 oC in vitro.In addition,taking Egyptian peanuts as a research object,shelled peanuts at 0.93 aw were inoculated with two concentrations of A.flavus conidia(103,105 conidia/g)and exposed to gaseous O_(3) and then stored.In all cases,exposure was for 30 min at 6 L/min.Generally,>100 ppm O_(3) significantly inhibited conidial germination of A.flavus strains(EGP-B07;SRRC-G 1907)on a defined yeast sucrose medium within 48 hrs.However,exposure of growing colonies of A.flavus to O_(3) with up to 300 ppm,had no effect on subsequent colony extension.The same concentration significantly affected AFB1 production,but only at 0.89 aw.Populations of both A.flavus strains in stored shelled peanuts exposed at 0.93 aw were significantly decreased at 100~400 ppm O_(3).However,AFB1 production was only significantly reduced in the 400 ppm O_(3) treatments at both inoculum load levels.These results are discussed in the context of O_(3) gas use for controlling A.flavus populations and AFB1 in shelled peanuts post-harvest.

Influencing Factors and Biological Control of Aflatoxin Contamination in Peanuts

Peanut is an important economic crop and oil crop in China.It is vulnerable to infection by Aspergillus flavus during production,storage,transportation and processing,causing aflatoxin(AFT)contamination.This paper introduced the status and characteristics of AFT contamination in China,analyzed the infection pathways and influencing factors of A.flavus,and discussed the prevention and control technology of AFT contamination in peanuts from the view of the use of beneficial microorganisms.

Study on Key Techniques for Precise and Quantitative, Stable and High Yield Cultivation of Peanuts in Eastern Henan Region

Peanut is a main industrial crop in the eastern Henan region. Its benefits directly affect the economic income of local farmers. Therefore, scientific cultivation of peanuts is an important way to increase farmers' income in the eastern Henan region. This paper firstly introduced the key techniques for precise and quantitative, stable and high yield cultivation of peanuts in the eastern Henan region. From the field selection, scientific seed selection, precise quantitative sowing, fertilizer and water management, chemical control technologies, prevention and control of pests and diseases, and timely harvesting, it made an in-depth analysis. It is expected to provide data references for further improvement of stale and high yield cultivation technical system, and provide technical guidance for raising the peanut planting level of peanut growers.

Correlation of Aflatoxin Contamination in Peanuts with Rhizosphere Microorganisms and Its Comprehensive Control

Aflatoxin contamination is an important hazard factor affecting the quality safety and food safety of peanut production, which seriously threatens people's health and safety. In this paper, the background and harmful causes of aflatoxin contamination were analyzed in detail, with attention focusing on its control measures, which has certain guiding significance for the comprehensive control of aflatoxin contamination.

Biochemical Composition and Disease Resistance in Newly Synthesized Amphidiploid and Autotetraploid Peanuts

Genetic diversity in peanut (Arachishypogaea L.) is narrow due to its evolution and domestication processes. Amphidiploids and autotetraploids (newly synthesized tetraploids) were created to broaden its genetic base. Molecular analysis has shown that the newly synthesized tetraploids had broader genetic base;and were genetically divergent when compared to cultivated peanut. Nutritional composition relative to oil, fatty acid composition, O/L ratio, protein, iodine value and presence of plant proteinase inhibitors such as trypsin and chymotrypsin inhibitors were studied in the synthesized tetraploids. Some of the newly synthesized tetraploids had higher amounts of proteinase inhibitors. Evaluation of newly synthesized tetraploids revealed several lines resistant to late leaf spot (LLS) and peanut bud necrosis disease (PBND).

Effect of non-aflatoxigenic strains of Aspergillus flavus on aflatoxin contamination of pre-harvest peanuts in fields in China

Aflatoxin contamination of peanuts is one of the most concerns in peanut production in China.Applying nonaflatoxigenic Aspergillus flavus strains,based on competitive exclusion,has been proved to be a promising strategy to reduce aflatoxin contamination in pre-harvest peanuts.Two non-aflatoxigenic A.flavus strains collected in China,which have been proved effectively reducing aflatoxin in the laboratory,were mixed with high aflatoxin producer to the soil in peanut growing season.The two non-aflatoxigenic strains significantly(P<0.05)reduced aflatoxin contamination in peanut kernels under both normal and drought stresses in two fields.Compared to control,the total aflatoxin(sum of aflatoxin B1 and B2)was reduced 26.7–99.12%in field 1,and 84.96–99.33%in field 2.The aflatoxin was reduced 84.96–99.33%under drought stress in two fields.The present study indicated the non-aflatoxigenic A.flavus strains could be potential biocontrol agents for reducing aflatoxin contamination under field condition.

High-yield and High-efficiency Standardized Cultivation Technique for Wheat Interplanting with Peanuts

Through wheat interplanting with peanuts,it is able to make full use of the light and heat resources in the growing season to achieve high yield of both wheat and peanuts in two seasons of one year.Wheat interplanting with peanuts is one of the main cultivation methods of wheat and oil crop double cropping system,and has very broad development prospects in the Huang-Huai-Hai region.This paper summarized high-yield the high-efficiency and standardized cultivation techniques for wheat interplanting with peanuts,including crop rotation,proper deep ploughing,balanced fertilization,rational matching of fine varieties,interplanting at suitable time,sowing according to certain specification,and enhancing the field management.This can be used as reference for high-yield and high-efficiency standardized cultivation technique for wheat interplanting with peanuts.

Comparison of anthocyanin and fatty acid in black and ordinary peanuts

In this study, anthocyanin and fatty acid compositions between black and ordinary peanuts were compared. Results showed that black peanuts contained 93.90±18.36 μg/g of cyanidin, which was significantly higher than that of ordinary peanuts. In addition, although both of black and ordinary peanuts shared some specific fatty acids, 4 fatty acids in black peanuts were significantly different from those in ordinary peanuts, which could be used as markers to distinguish black peanut from ordinary ones. This study might serve as a reference for authenticity identification and further nutritional researches on black peanut.

Excessive manure application stimulates nitrogen cycling but only weakly promotes crop yields in an acidic Ultisol:Results from a 20-year field experiment

Population growth and growing demand for livestock products produce large amounts of manure,which can be harnessed to maintain soil sustainability and crop productivity.However,the impacts of excessive manure application on crop yields,nitrogen(N)-cycling processes and microorganisms remain unknown.Here,we explored the effects of 20-year of excessive rates(18 and 27 Mg ha^(–1)yr^(–1))of pig manure application on peanut crop yields,soil nutrient contents,N-cycling processes and the abundance of N-cycling microorganisms in an acidic Ultisol in summer and winter,compared with none and a regular rate(9 Mg ha^(–1)yr^(–1))of pig manure application.Long-term excessive pig manure application,especially at the high-rate,significantly increased soil nutrient contents,the abundance of N-cycling functional genes,potential nitrification and denitrification activity,while it had a weaker effect on peanut yield and plant biomass.Compared with manure application,seasonality had a much weaker effect on N-cycling gene abundance.Random forest analysis showed that available phosphorus(AP)content was the primary predictor for N-cycling gene abundance,with significant and positive associations with all tested N-cycling genes.Our study clearly illustrated that excessive manure application would increase N-cycling gene abundance and potential N loss with relatively weak promotion of crop yields,providing significant implications for sustainable agriculture in the acidic Ultisols.

Fine-mapping of a candidate gene for web blotch resistance in Arachis hypogaea L.

Peanut(Arachis hypogaea L.)is a globally important oil crop.Web blotch is one of the most important foliar diseases affecting peanut,which results in serious yield losses worldwide.Breeding web blotch-resistant peanut varieties is the most effective and economically viable method for minimizing yield losses due to web blotch.In the current study,a bulked segregant analysis with next-generation sequencing was used to analyze an F2:3 segregating population and identify candidate loci related to web blotch resistance.Based on the fine-mapping of the candidate genomic interval using kompetitive allele-specific PCR(KASP)markers,we identified a novel web blotch resistance-related locus spanning approximately 169 kb on chromosome 16.This region included four annotated genes,of which only Arahy.35VVQ3 had a non-synonymous single nucleotide polymorphism in the coding region between the two parents.Two markers(Chr.16.12872635 and Chr.16.12966357)linked to this gene were shown to be co-segregated with the resistance of peanut web blotch by 72 randomly selected recombinant inbred lines(RIL),which could be used in marker-assisted breeding of resistant peanut varieties.