Variation in Intensity of Sweet and Bitter Sensory Attributes Across Peanut Genotypes1

Abstract

Abstract Genetic improvement of sweet, bitter and roasted peanut attributes of peanut (Arachis hypogaea L.) flavor is predicated on the existence of genetic variation for the attributes. A total of 1136 SMK samples representing 122 cultivars and breeding lines and 42 year-by-location combinations from three major peanut-producing regions were roasted, ground to paste, and submitted to a trained sensory panel for evaluation of flavor attributes. Data were subjected to analysis of variance to separate genetic, environmental and GxE interaction effects following adjustment for roast color and intensity of the fruity attribute. Genotypic variation was significant for all three attributes as was location-to-location variation within year and region. Large year effects were observed for bitter and roasted peanut attributes. Estimates of broad-sense heritability (H) among inbred lines and cultivars were 0.28 for sweet, 0.06 for bitter, and 0.06 for roasted peanut attributes, indicating that selection for sweetness should result in relatively rapid genetic gain. The ranges of genotypic means were 2.33-4.12 flavor intensity units (fiu) for sweet, 2.43-4.46 fiu for bitter, and 3.75-5.22 fiu for roasted peanut. Correlations among least squares means for the three attributes were highly significant (r = −0.80 for bitter and sweet, r = 0.59 for roasted peanut and sweet, and r = −0.59 for roasted peanut and bitter), indicating that indirect selection based on the more highly heritable sweet attribute could be more effective than direct selection for increased intensity of the roasted peanut and decreased intensity of the bitter attribute. Specific genotypes with superior aspects of roasted peanut flavor were identified.