Selection of alternative genetic sources of large-seed size in Virginia-type peanut: evaluation of sensory, composition, and agronomic characteristics.

Abstract

Jenkins Jumbo, the ancestral source of large-seed size in the Virginia market type (Arachis hypogaea L.), has been shown to have a deleterious effect on flavor of peanut. The pervasiveness of Jenkins Jumbo in the ancestry of large-seeded germplasm contributes to the generally less intense roasted peanut flavor of U.S. cultivars of the Virginia market type. As a remedy to this problem, alternative sources of large-seed size were sought. Nine large-seeded selections, with NC 7 and Florunner as checks, were tested in replicated trials in North Carolina and Florida from 1996 to 1998. Pod yield, grade, weight of 100 seeds, and oil, sugar, and starch contents were measured. A descriptive sensory panel evaluated flavor attributes of a roasted sound mature kernel (SMK) sample from each plot. NC 7 scored low for sweet sensory attribute, high for bitter, and median for roasted peanut. UF714021, a multiline incorporating the Altika cultivar with several sister lines, had the best flavor profile of the large-seeded selections, but it did not have particularly large seeds relative to NC 7. The largest seeded selections were X90037 and X90053, both derived from Japan Jumbo. Flavor scores for X90037 were similar to those for NC 7 for roasted peanut (3.0 vs 2.9 flavor intensity units, fiu) and sweet (2.7 vs 2.6 fiu) but worse than NC 7 for bitter (3.3 vs 3.7 fiu) and astringent (3.5 vs 3.7 fiu). X90053 had intermediate values for roasted peanut and astringent, high value for sweet, and low for bitter. Other lines that had or were likely to have Jenkins Jumbo as a recent ancestor were generally poor in roasted flavor, supporting the hypothesis that ancestry from Jenkins Jumbo imparts poor flavor characteristics. With the exception of the unexpected relationship between astringent attribute and extra large kernel (ELK) content (r = 0.82, P < 0.01), there were no significant correlations between sensory attributes and the important agronomic traits: yield, meat, and ELK content. Among the nine large-seeded lines tested in this study, three appear to have greater potential for use as parents: 86x45B-10-1-2-2-b2-B, UF714021, and X90053.