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Products from peanut seeds are nutritious for human and/or animal consumption. Peanut seed nutritional quality is determined by the genotype (G) of cultivars or accessions, environmental conditions (E), and their interactions (G × E). To evaluate the effects of genotype, environment, and their interactions on seed nutritional quality, 52 peanut germplasm accessions, which vary in oil content and fatty acid composition, were planted at three locations (Citra, FL; Byron, GA; and Clovis, NM) for 2 years (2017 and 2018). The harvested seeds were analyzed for protein, oil, and fatty acid composition using an N analyzer, nuclear magnetic resonance, and gas chromatography, respectively. Significant effects of accession, FAD2 gene, where FAD is fatty acid desaturase, location, year, and their interactions on the investigated traits were evaluated. The average oil content from accessions grown in Florida (51.1%) or Georgia (50.7%) was significantly higher than those grown in New Mexico (45.8%), whereas the average protein content from accessions grown in Florida (23.2%) was significantly lower than those grown in New Mexico (25.4%) or Georgia (24.8%). This is expected as there is a negative correlation between oil and protein content. After genotyping and classification (A/A, A/W, and G/W) for the FAD2A/FAD2B genes, the nutritional quality variations were further evaluated at the levels of the specific haplotype of FAD2A/FAD2B and explicit environmental index. The average prediction accuracy of seed nutritional quality trait values from the prediction model demonstrated that predicting trait values in new environments is feasible. The results of this study provide insights into the seed nutritional analysis, germplasm evaluation, and peanut breeding, cultivation, and production to peanut breeders, curators, farmers, and product processors. Core Ideas: Genotype, environment, and their interactions affect peanut seed nutritional quality.The FAD2A/FAD2B gene (F) effect significantly alters seed fatty acid composition.Location (L) effect significantly changes seed oil and protein content.Photothermal time may be a good parameter for representing the growing location environmental conditions for data analysis.Recommendation was given to farmers and processors on how to cultivate the right peanut varieties and purchase the right seeds from specific regions. [ABSTRACT FROM AUTHOR]

Sclerotium rolfsii is a necrotrophic fungus that causes devastating stem rot disease on peanuts under high temperature and humidity conditions. Developing more resistant stem rot varieties is a better disease management strategy from an economic and environmental point of view. In this study, 105 peanut accessions from the USDA mini-core collection were screened for resistance against stem rot under growth chamber and greenhouse conditions at the New Mexico State University Agricultural Science Center in Clovis, NM, USA. The accessions were inoculated with a virulent isolate of S. rolfsii, and disease development was monitored and scored at 5, 7, 9, 11, and 17-days post-inoculation (DPI). Mean disease score, lesion length and broad sense heritability were calculated, and cluster analysis was performed. Though the accessions were not significantly different for the mean disease parameters, numerical differences were observed in disease score and lesion length among the accessions at 17-DPI. Eleven accessions showed moderate resistance and performed better than stem rot resistant commercial cultivar, 'G03L', and ninety-four accessions were susceptible based on mean disease scores under both growing conditions. Low broad-sense heritability for disease score (0.05 to 0.06) and lesion length (0.03 to 0.06) under different environments indicates that most of the variance for these traits is due to environmental effects, and that stem rot resistance can be a complex trait. The identified resistant accessions can be used for genotyping and finding major QTLs through genome-wide association mapping to dissect genetic basis of stem rot resistance in peanuts. This information would be helpful to the peanut breeding program to develop more resistant varieties. [ABSTRACT FROM AUTHOR]

'Naronut 1R' (Reg. no. CV‐150, PI 693985) is a high‐yielding, Spanish‐type groundnut (Arachis hypogaea L. subsp. fastigiata var. vulgaris) cultivar with a red seed coat and two seeds per pod. The cultivar was selected from a cross between International Crops Research Institute for the Semi‐arid Tropics advanced lines 'ICGV‐SM 90704' and 'ICGV‐SM 86715'. Naronut 1R was developed for groundnut rosette disease resistance, late leafspot resistance, yield, red seed coat, and early maturity. Naronut 1R matures in 75–80 d after planting, compared with 90 d for the widely grown and popular landrace Erudu red (Spanish‐type groundnut). Naronut 1R has much higher yields (1,473 kg ha−1) than Erudu red (554 kg ha−1). The overall groundnut rosette disease rating was 44% lower in Naronut 1R (2.8 disease rating) compared with Erudu red (5.0 disease rating). Similarly, the overall late leafspot disease rating was 28% lower in Naronut 1R (3.6 disease rating) compared with Erudu red (5.0 disease rating). Similar to Erudu red, Naronut 1R seed testa is red, but the seed is larger. The sound mature kernel weight was 9.42% higher for Naronut 1R than for Erudu red. The shelling percentage for Naronut 1 was 49.3%, whereas Erudu red was 60%. Naronut 1R has lower protein (18.1 vs. 21.3%) and oil content (36.0 vs. 44.3%) than Erudu red. Naronut 1R will allow for broad adoption of a high yielding, early maturing, red seed coat cultivar that carries resistance to groundnut rosette disease and late leaf spot disease. Core Ideas: Naronut 1R is a high‐yielding, very early‐maturing peanut cultivar.Naronut 1R is resistant to groundnut rosette disease and late leaf spot disease.Naronut 1R is broadly adaptable across sub‐Saharan Africa. [ABSTRACT FROM AUTHOR]

Peanut (Arachis hypogaea L.) is the second-most important legume crop in the United States. A limitation to increased peanut productivity is that peanut improvement is hampered by relatively low genetic variability in the germplasm commonly used by breeding programs. To facilitate accessibility to diverse germplasm sources for breeding applications, a core subset of the USDA peanut germplasm was previously established that later was further refined and developed into a mini core collection consisting of 112 accessions. This report details an extensive characterization of genetic diversity and relationships in the U.S. peanut mini core using microsatellite or simple sequence repeat (SSR) markers. Seventy-two peanut accessions from the U.S. peanut mini core were genotyped with 73 SSR markers; all but six produced reliable, polymorphic bands. Moderate levels of genetic variation were found with genetic distances (D) values among accessions ranging from 0.088 to 0.254. Distinct groupings of the accessions based on subspecies classification and on botanical (market) type groupings were established. Twelve of the markers, mapped previously to the A genome, were found to be sufficient to identify both subspecies and botanical types and gave a clustering pattern very similar to the entire 67 SSR marker set. The genetic variation observed within U.S. peanut mini core can be utilized for selection of diverse parents for breeding and development of mapping populations.

Abstract Background Transcriptome expression analysis in peanut to date has been limited to a relatively small set of genes and only recently has a significant number of ESTs been released into the public domain. Utilization of these ESTs for oligonucleotide microarrays provides a means to investigate large-scale transcript responses to a variety of developmental and environmental signals, ultimately improving our understanding of plant biology. Results We have developed a high-density oligonucleotide microarray for peanut using 49,205 publicly available ESTs and tested the utility of this array for expression profiling in a variety of peanut tissues. To identify putatively tissue-specific genes and demonstrate the utility of this array for expression profiling in a variety of peanut tissues, we compared transcript levels in pod, peg, leaf, stem, and root tissues. Results from this experiment showed 108 putatively pod-specific/abundant genes, as well as transcripts whose expression was low or undetected in pod compared to peg, leaf, stem, or root. The transcripts significantly over-represented in pod include genes responsible for seed storage proteins and desiccation (e.g., late-embryogenesis abundant proteins, aquaporins, legumin B), oil production, and cellular defense. Additionally, almost half of the pod-abundant genes represent unknown genes allowing for the possibility of associating putative function to these previously uncharacterized genes. Conclusion The peanut oligonucleotide array represents the majority of publicly available peanut ESTs and can be used as a tool for expression profiling studies in diverse tissues.

The level of oleic acid is an important parameter in determining seed nutritional quality and oil stability. The level of oleic acid in peanut is genetically controlled by a pair of fatty acid desaturase genes (FAD2A and FAD2B), but the environmental conditions of the production sites can also have a significant effect. To investigate the effect of gene and environment interaction, 45 accessions were grown at three locations for 2 years. Environmental data were collected; individual plants were genotyped with functional SNP markers from FAD2A and FAD2B; and seed level of oleic acid was determined by gas chromatography. Three FAD2A/FAD2B genotypes (448G/no insertion 442A, 448A/no insertion 442A, and 448A/insertion 442A) were identified and designated as G/W, A/W, and A/A, respectively. A/A genotype averaged the highest level of oleic acid (80.0%), followed by A/W (56.0%), and then G/W (40.7%). Analysis of gene and environment interaction revealed that oleic acid phenotype plasticity could be explained by the interaction of FAD2 genotype and photothermal time, which quantified environmental conditions. The A/W genotype was the most sensitive to photothermal time changes. The oleic acid plasticity revealed in this study would be useful for breeders, farmers, and product processors. [ABSTRACT FROM AUTHOR]