Evaluation of variability in seed coat color, weight, oil content, and fatty acid composition within the entire USDA‐cultivated peanut germplasm collection

Abstract Natural genetic diversity in plant germplasm collections provides the genetic variability for crop improvement. To explore this natural genetic variability, over 8,800 accessions within the USDA cultivated peanut ( Arachis hypogaea L.) germplasm collection were evaluated for several seed quality traits including seed coat color, 100‐seed weight, oil content, and fatty acid composition. After removing contaminated and/or mixed accessions, the remaining 8,466 accessions were used for further data analysis. The mean of 100‐seed weight was 49.44 g with a wide range of 21.84 to 148.36 g (6.8‐fold difference). Six accessions (PI 414995, PI 648234, PI 318740, PI 336978, PI 320059, and PI 578229) with 100‐seed weight >110 g were identified. The mean of oil content was 48.94% with a range of 36.51 to 59.45% (1.6‐fold difference). Seven accessions (PI 471949, PI 472001, PI 497369, PI 442739, PI 343423, PI 161298, and PI 668582) with oil content >58% were identified. The mean of oleic acid was 45.2% with a wide range of 39.99 to 82.08% (2.1‐fold difference). The mean of linoleic acid was 32.56% with a wide range of 2.0 to 46.68% (23.3‐fold difference). Thirty‐seven accessions were identified with >65% oleic acid. Among them, PI 636472 and PI 596800 had the highest level of oleic acid (82.1 and 81.8%, respectively). Significant variation in these traits was also identified between subspecies and among botanical varieties. Some significantly positive and negative correlations among these traits were also determined. The results presented here will be useful for peanut breeders, geneticists, and other users.