Submitted to: Plant Genetic Resources: Characterization and Utilization
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 29, 2012
Publication Date: August 1, 2013
Citation: Panthee, D.R., Labate, J.A., Robertson, L.D. 2013. Evaluation of tomato germplasm for flavor and flavor contributing components. Plant Genetic Resources: Characterization and Utilization. 11:106-113. Interpretive Summary: Improvement of flavor in fresh-market tomatoes will be aided by conducting taste tests by trained panelists. Flavor is a complex trait that depends on sugars, acids and other compounds. We grew 173 different varieties of tomato in field trials in North Carolina in 2011. We used taste tests and asked participants to rate tomato flavor for qualities such as fruity odor, sweetness, saltiness, acidic flavor, juiciness and mealiness (unpleasant grainy texture). The same tomatoes were analyzed in the lab for amount of sugar, acid and fruit firmness, among other traits. We found that overall good flavor was related to sugar and acid, and we identified relationships between various measured qualities of the tomatoes and flavor. The results of this study provided measurements of the ranges of flavor-related components in the set of 173 tomato varieties. This will contribute to improvement of tomato flavor by helping breeders to decide which varieties will be most promising for changing particular aspects of flavor.
Technical Abstract: Flavor is one of the most highly demanded consumer traits of tomato at present; poor flavor is one of the most commonly heard complaints associated with modern varieties of tomato. Research in the past has identified reducing sugars, organic acids and approximately 30 plant volatiles as either directly impacting flavor or exerting an effect through interactions with other compounds. In order to combine flavor with other desirable fruit traits in improved cultivars, it is important to determine how much variability exists in the crucial compounds that contribute most to flavor. The objective of the present study was to determine the variability of flavor-contributing components including total soluble sugars (TSS) and total titrable acids (TTA) among other subjective traits related to flavor in a core collection of tomato germplasm. The core collection was comprised of 173 tomato genotypes from USDA, ARS Plant Genetic Resources Unit repository with a wide genetic background. The TTA varied from 0.20 to 0.64% whereas the TSS ranged from 3.4 to 9.0% indicating the availability of broad variation for these traits. Rinon (PI 118783), Turrialba, Purple Calabash and LA2102 were among the high TTA (>0.45%) containing genotypes whereas those with high TSS (>7.0%) were AVRDC#6, Sponzillo and LA2102. A positive correlation of overall flavor measured by untrained panelists with TTA (r=0.33; p<0.05) and TSS (r=0.37; p<0.05) indicated that these two components play an important role in determining the overall flavor in tomato. Subjectively measured other traits including fruity odor and fruity flavor had positive correlations with overall flavor. Overall flavor is discussed in the context of other traits including fruit firmness. Information obtained from this study will be useful for tomato breeders aiming to improve tomato flavor.