Genotype, environment, and their interaction effects on peanut seed protein, oil, and fatty acid content variability

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 x 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. 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.