Submitted to: Peanut Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/18/1998
Publication Date: N/A
Interpretive Summary: Sweetness, bitterness and roasted peanut flavor intensity are important consumer quality characteristics of peanut products. Improvement of these characteristics in new peanut varieties is dependent upon the existence of genetic variation for these characteristics. To determine if genetic variation existed, 1136 samples representing 122 peanut lines and 42 year location combinations from three major peanut-producing regions were examined for these characteristics. The presence of genetic variation was found and the estimates of the variation were determined. They were found to be 28% for sweetness, 6% for bitterness, and 6% for roasted peanut. The high genetic variation for sweetness suggests that rapid improvement could be made in future varieties using standard plant breeding practices. The intensity ranges across peanut lines were 2.3-4.1 flavor intensity units (fiu) for sweetness, 2.4-4.5 fiu for bitterness, and 3.8-5.2 fiu for roasted peanut. The causal relation between these attributes was highly significant. The high positive causal relationship between sweetness and roasted peanut indicates that any improvement in the sweetness character would also result in improvement in the roasted peanut character. Using this information we have identified specific peanut lines with superior aspects of roasted peanut flavor.
Technical 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-location combinations from three major peanut-producing regions were evaluated. Genotypic variation was significant for the sweet, bitter and roasted peanut attributes as was location-to-location variation within year and region. Large year effects were also observed for bitter and roasted peanut attributes. Estimates of broad-sense heritability among inbred lines and cultivars were 0.28 for sweet, 0.06 for bitter, and 0.06 for roasted peanut, indicating that selection for sweetness should result in relatively rapid genetic gain. The ranges of genotypic means were 2.3-4.1 flavor intensity units (fiu) for sweet, 2.4-4.5 fiu for bitter, and 3.8-5.2 fiu for roasted peanut. Correlations among least square means 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.