Oil Content In Peanut Research Articles

High-resolution mapping through whole-genome resequencing identifies two novel QTLs controlling oil content in peanut

Increasing oil content is a key objective in peanut breeding programs. Accurate identification of quantitative trait loci (QTLs) with linked markers for oil content can greatly aid in marker-assisted selection for high-oil breeding. In this study, a high-density bin map was constructed by resequencing a recombinant inbred line (RIL) population (ZH16×J11) consisting of 295 lines. The bin map contained 4,212 loci and had a total length of 1,162.3 cM. Ten QTLs for oil content were identified in six linkage groups. Notably, two of these QTLs, qOCB03.1 and qOCB06.1, were consistently detected in a minimum of three environments and explained up to 13.62% of phenotypic variation. They have not been reported in previous studies and thus are novel QTLs. The combination of favorable alleles from the qOCB03.1 and qOCB06 in the RIL population could increase oil content across multiple environments from 1.50 to 2.46%. Two InDel markers linked to qOCB03.1 and qOCB06.1 were developed and validated to be associated with oil content in another RIL population (ZH10×ICG12625) with diverse phenotypes. Additionally, the high-resolution map allowed for the precise positioning of qOCB03.1 and qOCB06.1 within a 1.77 Mb-interval on chromosome B03 and a 1.51 Mb- interval on chromosome B06, respectively. Annotation of genomic variants, analysis of transcriptome sequencing, and evaluation of the allelic effects in 292 peanut varieties revealed two candidate genes associated with oil content for each of the two QTLs. The identification of candidate genes in this study can enable the map-based cloning of key genes controlling oil content in peanut. Furthermore, these novel and stable QTLs and their tightly linked markers are valuable for marker-assisted breeding for increased oil content in peanut.

Genetic analysis and exploration of major effect QTLs underlying oil content in peanut.

AhyHOF1, likely encoding a WRI1 transcription factor, plays critical roles in peanut oil synthesis. Although increasing the oil content of peanut to meet growing demand has long been a primary aim of breeding programs worldwide, the mining of genetic resources to achieve this objective has obviously lagged behind that of other oil crops. In the present study, we developed an advanced recombinant inbred line population containing 192 F9:11 families derived from parents JH5 and KX01-6. We then constructed a high-resolution genetic map covering 3,706.382cM, with an average length of 185.32cM per linkage group, using 2840 polymorphic SNPs. Two stable QTLs, qCOA08_1 and qCOA08_2 having the highest contributions to genetic variation (16.1% and 20.7%, respectively), were simultaneously detected in multiple environments and closely mapped within physical intervals of approximately 2.9Mb and 1.7Mb, respectively, on chromosome A08. In addition, combined analysis of whole-genome and transcriptome resequencing data uncovered a strong candidate gene encoding a WRI1 transcription factor and differentially expressed between the two parents. This gene, designated as High Oil Favorable gene 1 in Arachis hypogaea (AhyHOF1), was hypothesized to play roles in oil accumulation. Examination of near-inbred lines of #AhyHOF1/#Ahyhof1 provided further evidence that AhyHOF1 increases oil content, mainly by affecting the contents of several fatty acids. Taken together, our results provide valuable information for cloning the favorable allele for oil content in peanut. In addition, the closely linked polymorphic SNP markers within qCOA08_1 and qCOA08_2 loci may be useful for accelerating marker-assisted selection breeding of peanut.

Bio-fertilizers\u2019 protocol for controlling root knot nematode Meloidogyne javanica infecting peanut fields

BackgroundPlant parasitic nematodes create serious threat to crop production. In Egypt root knot nematode, Meloidogyne spp. has been considered to be a limiting factor in the production of most crops of which the Peanut (Arachis hypogaea L.) is an important legume and oil crop. Therefore, management of root knot nematodes Meloidogyne spp. is an obligatory challenge. Microbial organisms are extensively used as eco-friendly tools for controlling plant parasitic nematodes as alternative to chemical nematicides. The effectiveness of the commercial bacterial bio-fertilizers NPK containing Bacillus polymyxa, B. circulance, B. megaterium, Pseudomans spp.; the nitrogen fixative bacteria Azotobacter chroocoocum and the bacterial isolate NRC211 were evaluated against the root knot nematode, Meloidogyne javanica infecting peanut plants under field conditions. Identification of the bacterial isolate was made through PCR amplification and sequencing of 16S rDNA gene.ResultsSequencing of 16S rDNA gene revealed that the bacterial isolate NRC211 had 100% similarity with Bacillus wiedmannii strain FSL W8-0169 16S ribosomal RNA. This Bacillus was recorded for the first time under accession number LC626774 on GenBank data base as B. wiedmannii NRC211. Recorded data revealed that all the tested treatments whether single or combined in soil naturally infested with M. javanica, resulted in variable significant reduction in the nematode reproductive parameters with a considerable increase in crop production and oil content of peanut plant. These results were improved by increasing the frequency of application of the bio-agents. In this respect the repeated combined treatment of A. chroococcum and B. wiedmannii NRC211 treatment overwhelmed all other treatments in decreasing nematode reproductive parameters with percentage reductions of 94.8, 79.0 and 80.1% in M. javanica juveniles in soil, galls and egg masses, respectively. This was associated with slight increase in peanut oil content than the untreated control. The repeated combined treatment of NPK plus A. chroococcum produced the highest increase 608.7%, and 72.7% in crop production and plant growth parameters, respectively than the control. While, the oil content in this treatment was increased up to 47.4 g/kg.ConclusionIt was concluded that B. wiedmanni NRC211 is an eco-friendly bio agent that can be applied with other commercial microbial bio-fertilizers in bio-integrating programs for controlling M. javanica infecting peanut plants.

Global Transcriptome Analyses Provide Into Several Fatty Acid Biosynthesis-related Genes in Peanut (Arachis hypogaea L.)

Peanut (Arachis hypogaea L.) is one of the important oil crops worldwide. Revealing the molecular basis of seed oil synthesis and analyzing key candidate genes may have important implications for enhancing peanut production. In this study, we investigated the dynamic changes in the oil accumulation rate and gene expression levels in developing peanut seeds. A Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that the up-regulated differentially expressed genes (DEGs) among three varieties at 25–35 days after flowering (DAF) were involved in fatty acid synthesis, carbon metabolism, and pyruvate metabolism. Between 25 and 35 DAF, the up-regulated DEGs in the high-oil varieties, but not in the low-oil variety, were related to acetyl-CoA synthesis. We examined the differences in the varieties at the same stages. We analyzed the lipid metabolism-related genes by protein–protein interaction (PPI), and finally identified 57 DEGs that may influence the peanut oil content. These candidate genes included three genes encoding acetyl-CoA carboxylase (ACCase), one gene encoding ketoacyl-ACP synthase III (KASIII), one gene encoding hydroxyacyl-ACP dehydrase (HAD), and one gene encoding enoyl-ACP reductase (EAR), which form the Type II fatty acid synthase complex. Additionally, we also found that 11 transcription factors may affect oil content. These identified candidate genes may help to further clarify the molecular basis of the oil accumulation in peanut seeds.

Identification of two major loci and linked marker for oil content in peanut (Arachis hypogaea L.)

Peanut is one of major sources for vegetable oil. Improving oil content is an important goal for peanut breeding programs. Major loci with linked markers for oil content could facilitate rapid development of high-oil varieties through marker-assisted breeding. To identify major loci underlying the oil content, we conducted the QTL analysis based on the high-dense genetic map, using RIL population derived from Zhonghua10 and ICG12625. A total of 18 additive QTLs, including two major and stable QTLs (qOCB06 and qOCB10.1), were identified in three environments. Besides, 26 pairs of QTLs with epistatic (additive × additive) interaction were mapped on 17 linkage groups. qOCB06 with up to 22.59% of the phenotypic variations was located in a 0.6-Mb interval of B06. qOCB10.1 on B10 explained 9.18–12.55% of the phenotypic variations. The additive effect of two QTLs ranged from 0.70 to 1.13% oil content in different environments. Favorable alleles of the two loci were from male and female parent, respectively. Pyramiding the two favorable alleles in the RIL population could increase “2.66 ± 0.48%” oil content across multiple environments. The marker Ai06B29452 and AGGS2133-1 linked to qOCB06 and qOCB10.1, respectively, were validated to be associated with oil content in peanut germplasms with diverse phenotypes. These markers were valuable in marker-assisted selection and pyramiding breeding for improving oil content in peanut. Major and stable QTLs with linked markers in the present study provided resources to discovery candidate genes in the future and to guide marker-assisted selection for improving oil content in peanut.

Diallel Analysis of Seed Yield, its Components and Oil Content in peanut

A half diallel set including diverse five parental peanut genotypes was evaluated at Ismailia Agricultural Research Station, ARC,Ismailia Governorate,Egypt using randomized complete block design with three replications to estimate mean performance,combining ability,heterosis and nature of gene action.Highly significant genotypes and its components of parents,crosses and parents vs.crosses mean squares were detected for all studied traits.Highly significance of general and specific combining ability was observed for all studied traits.Additive gene action governed in plant height, number of pods/plant, number of seeds/plant,100-pod weight and shelling %. Ismalia 2,Line 360 and Giza 6 seemed to be the best combiners for pod yield /feddan and most of its components.The best cross combinations were detected in F1 crosses, P2 ×P3 for seed weight /plant and P3 × P5 and P4 × P5 for pod yield / feddan.Significant or highly significant values and high values of the dominance component (H1) were also observed for the most studied traits. P5 carried the most dominant genes responsible for the expression of seed weight/plant and pod yield / feddan, while, P4 for seed weight / plant and P1 and P2 for pod yield / feddan possessed high concentration of recessive genes. It could be concluded that, Ismalia2, Line 360 and Giza6 could be used as donors parents to improve yield and its components of peanut in the breeding program,also, the crosses P2 ×P3 , P3 × P5 and P4 × P5 with high SCA may be exploited for the development of hybrids as they had high per se performance.

Characterization of glycerol-3-phosphate acyltransferase 9 (AhGPAT9) genes, their allelic polymorphism and association with oil content in peanut (Arachis hypogaea L.)

GPAT, the rate-limiting enzyme in triacylglycerol (TAG) synthesis, plays an important role in seed oil accumulation. In this study, two AhGPAT9 genes were individually cloned from the A- and B- genomes of peanut, which shared a similarity of 95.65%, with 165 site differences. The overexpression of AhGPAT9 or the knock-down of its gene expression increased or decreased the seed oil content, respectively. Allelic polymorphism analysis was conducted in 171 peanut germplasm, and 118 polymorphic sites in AhGPAT9A formed 64 haplotypes (a1 to a64), while 94 polymorphic sites in AhGPAT9B formed 75 haplotypes (b1 to b75). The haplotype analysis showed that a5, b57, b30 and b35 were elite haplotypes related to high oil content, whereas a7, a14, a48, b51 and b54 were low oil content types. Additionally, haplotype combinations a62/b10, a38/b31 and a43/b36 were associated with high oil content, but a9/b42 was a low oil content haplotype combination. The results will provide valuable clues for breeding new lines with higher seed oil content using hybrid polymerization of high-oil alleles of AhGPAT9A and AhGPAT9B genes.

Dissection of the genetic basis of oil content in Chinese peanut cultivars through association mapping

BackgroundPeanut is one of the primary sources for vegetable oil worldwide, and enhancing oil content is the main objective in several peanut breeding programs of the world. Tightly linked markers are required for faster development of high oil content peanut varieties through genomics-assisted breeding (GAB), and association mapping is one of the promising approaches for discovery of such associated markers.ResultsAn association mapping panel consisting of 292 peanut varieties extensively distributed in China was phenotyped for oil content and genotyped with 583 polymorphic SSR markers. These markers amplified 3663 alleles with an average of 6.28 alleles per locus. The structure, phylogenetic relationship, and principal component analysis (PCA) indicated two subgroups majorly differentiating based on geographic regions. Genome-wide association analysis identified 12 associated markers including one (AGGS1014_2) highly stable association controlling up to 9.94% phenotypic variance explained (PVE) across multiple environments. Interestingly, the frequency of the favorable alleles for 12 associated markers showed a geographic difference. Two associated markers (AGGS1014_2 and AHGS0798) with 6.90–9.94% PVE were verified to enhance oil content in an independent RIL population and also indicated selection during the breeding program.ConclusionThis study provided insights into the genetic basis of oil content in peanut and verified highly associated two SSR markers to facilitate marker-assisted selection for developing high-oil content breeding peanut varieties.

Dark chocolate with a high oleic peanut oil microcapsule content.

In accordance with the market demand for healthier indulgent food products, the present study aimed to determine the viability of the industrial production of dark chocolate with microcapsules of high oleic peanut oil content. Microcapsules of high oleic peanut oil were added to a control formulation using variations of mixing time. The chocolates presented a rheology characterized by a pseudoplastic behavior adjusted to the Casson model (r > 0.98) and calorimetric behavior indicating melting onset (21 °C), peak melting (32 °C) and melting end (41 °C); caramelization peak (183 °C); and carbonization peak (237 °C), being considered thermal stable. The mixing time and the amount of microcapsules added to the control chocolate did not significantly influence the flow limit (11.09 ± 1.73 Pa) or the physical characteristics of the chocolate: pH (6.74 ± 0.14), maximum particle size (0.019 ± 0.001 mm), water activity (0.358 ± 0.023) and brittleness (18.61 ± 3.74 N). However, the addition of microcapsules with a high oleic peanut oil content significantly increased the chocolate whiteness index, thixotropy and Casson's plastic viscosity, although it did not have a significant influence on the mixing time. The products obtained have a desirable quality and physical properties, being suitable for industrial production. © 2018 Society of Chemical Industry.

Genomic and Transcriptomic Analysis Identified Gene Clusters and Candidate Genes for Oil Content in Peanut (Arachis hypogaea L.)

Peanut (Arachis hypogaea), a major source of vegetable oil in many Asian countries, has become an integral part of human diet globally due to its high nutritional properties and option to consume in different forms. In order to meet the demand of vegetable oil, many peanut breeding programs of China have intensified their efforts in increasing oil content in newly bred varieties for reducing the import of edible oils in China. In this context, transcriptome sequencing data generated on 49 peanut cultivars were analyzed to identify candidate genes and develop molecular markers for seed oil content across multiple environments. Transcriptome analysis identified 5458 differentially expressed genes (DEGs) including 2243 positive DEGs and 3215 negative DEGs involved in oil synthesis process. Genome-wide association study identified 48 significant insertion/deletion (InDel) markers associated with seed oil content across five environments. A comparative genomics and transcriptomics analysis detected a total of 147 common gene clusters located in 17 chromosomes. Interestingly, an InDel cluster associated with seed oil content on A03 chromosome was detected in three different environments. Candidate genes identified on A03 form a haplotype, in which variable alleles were found to be different in oil content in an independent population. This locus is important for understanding the genetic control of peanut oil content and may be useful for marker-assisted selection in peanut breeding programs.

DEVELOPMENT OF RAPD AND SSR MARKERS ASSOCIATED WITH OIL CONTENT IN FIVE PEANUT CULTIVARS

The peanut (Arachis hypogaea L.) is an important oilseed crop in tropical and subtropical regions of the world.Oil content has an important quality trait for peanut. However, the progress in genetic improvement of oil content is slow. Therefore, identification of molecular markers for oil content trait is a great impact in molecular breeding. Nineteen RAPD and ten SSR primers were used to detect markers related to oil content in peanut. The five peanut cultivars were grown for two seasons (2013, 2014) in El-Nubaria, Al-Beheira Governorate, and Egypt. The results showed that, Gregory cultivar recorded the highest value of oil content, while Giza5 cultivar exhibited the lowest value of oil content in both seasons. The results indicated the presence of five positive and nine negative RAPD markers and two positive and one negative SSR markers that could be considered as reliable markers for oil content in peanut.

The effect of heat treatment on phenolic compounds and fatty acid composition of Brazilian nut and hazelnut.

Brazilian peanut oil content increased with oven heating (65.08%) and decreased with microwave heating process (61.00%). While the phenolic content of untreated Brazilian nut was the highest of 68.97mg GAE/100g. Hazelnut (Sivri) contained the highest antioxidant activity (86.52%, untreated). Results reflected significantly differences between the antioxidant effect and total phenol contents of Brazilian nut and hazelnut (Sivri) kernels heated in the oven and microwave. Microwave heating caused a decrease in antioxidant activity of hazelnut. Gallic acid, 3,4-dihydroxybenzoic acid and (+)- and catechin were the main phenolic compounds of raw Brazilian nut with the value of 5.33, 4.33 and 4.88mg/100g, respectively, while the dominant phenolics of raw hazelnut (Sivri) kernels were gallic acid (4.81mg/100g), 3,4-dihydroxybenzoic acid (4.61mg/100g), (+)-catechin (6.96mg/100g) and 1,2-dihydroxybenzene (4.14mg/100g). Both conventional and microwave heating caused minor reduction in phenolic compounds. The main fatty acids of Brazilian nut oil were linoleic (44.39-48.18%), oleic (27.74-31.74%), palmitic (13.09-13.70%) and stearic (8.20-8.91%) acids, while the dominant fatty acids of hazelnut (Sivri) oil were oleic acid (80.84%), respectively. The heating process caused noticeable change in fatty acid compositions of both nut oils.

Genotype × Environment Interactions for Oil Content in Peanut and Stable High‐Oil‐Yielding Sources

Peanut (Arachis hypogaea L.) genotypes with superior and stable agronomic performance and high oil content were identified from testing of 160 advanced breeding lines over six seasons. The study revealed significant genotype and genotype × environment (G × E) interaction determining oil and protein content; shelling outturn; and pod, kernel, and oil yield in peanut. The variability among genotypes was high across the environments for pod yield (546–7382 kg ha−1), oil yield (301–2742 kg ha−1), oil content (37–60%), 100‐seed weight (21–127 g), and protein content (19–31%). The GGE biplot technique revealed that ICGV 05155 is a stable genotype for oil yield with an average oil yield of 1886 kg ha−1. ICGV 05155 recorded highest average pod yield of 4928 kg ha−1, kernel yield of 3420 kg ha−1, and oil content of 55.1%. ICGV 06049, ICGV 06041, ICGV 06420, and ICGV 03043 were other genotypes with stable oil yield. Simple regression showed significant contributions of oil content (18–54%), and kernel yield (92–99%) to oil yield across the environments. Simultaneous improvement of kernel yield and oil content is feasible in breeding programs, as kernel yield had no negative association with oil content. The high oil content genotypes, ICGV 05155, ICGV 06049, ICGV 06041, ICGV 06420, and ICGV 03043, with stable oil yield were promoted to multilocation adaptive trials required for their release for cultivation and used as parents in breeding programs and development of mapping population to identify quantitative trait loci (QTL) governing oil content.

Rapid and Non-destructive Determination of Oil Content of Peanut (Arachis hypogaea L.) Using Hyperspectral Imaging Analysis

Peanut (Arachis hypogaea L.) is rich in some important oils such as the high content of polyunsaturated fatty acids. The potential of hyperspectral imaging technique in the spectral range I (400–1000 nm) and II (1000–2500 nm) coupled with chemometrics analysis for predicting oil content in different peanut cultivars was investigated in this study. Hyperspectral images were obtained and the corresponding spectral data was extracted. Quantitative calibration models were established between pre-processing spectral data and the reference measured oil content by partial least squares regression (PLSR) analysis. By comparing the model performances based on different spectral pre-processing methods, the raw-PLSR models using full wavelengths presented better results with the determination coefficient (R2 p) of 0.696 and 0.923, and root mean square errors by prediction (RMSEP) of 0.416 % and 0.208 %, respectively. In addition, six optimal wavelengths in the spectral range II were selected based on the regression coefficients of the established raw-PLSR model. The simplified PLSR model established only using identified optimal wavelengths also showed good performance with R2 p of 0.934, and RMSEP of 0.197 %. The results demonstrated that hyperspectral imaging technique is a promising tool for rapid and non-destructive determination of oil content in peanut.

Variability of Total Oil Content in Peanut Across the State of Texas

The state of Texas has three major regions with a history of peanut production: South Texas, Central Texas, and West Texas. The Texas A&M AgriLife peanut breeding program conducts replicated advanced yield trials at multiple locations within each of these regions annually. This study was initiated using entries from these same advanced line tests to determine if there were inter-regional and/or intra-regional differences in total oil content. The study was comprised of five cultivars used as checks in our yield tests and five advanced breeding lines. Three replications of each entry were tested for two South Texas, two West Texas, and two Central Texas locations. All of the samples were tested using nuclear magnetic resonance (NMR), which is a non-destructive test to determine the total oil content. A significant genotype by environment interaction was observed in both years of the study. Significant genotype differences were observed in all locations except the Stephenville location, which was inoculated with Sclerotinia minor in 2008. Maturity was significantly correlated with oil content across all locations for 2009 data.

Identification of SSR Markers Linked to Oil Content in Peanut (<I>Arachis hypogaea</I> L.) through RIL Population and Natural Population

Identification of SSR Markers Linked to Oil Content in Peanut (<I>Arachis hypogaea</I> L.) through RIL Population and Natural Population

Effect of prolonged dietary treatment on atherosclerosis in the mature fowl

Summary The feeding of different rations to 20-month old Leghorn chickens for a period of 18 months resulted in a significant increase in the severity of abdominal aortic atherosclerosis in birds given an egg-enriched, balanced poultry ration, or the control ration supplemented with dicumarol. When birds were given a diet prepared from Army C rations and certain supplements to insure its nutritional balance and palatability, a significant decrease in aortic involvement was observed compared with that of controls or birds on the other treatments. It is suggested that the relatively high pectin and peanut oil content of the ration may be implicated. Additions of vitamin K 1 or of a combination of vitamins A, E and B 6 did not influence the degree of aortic atherosclerotic involvement.