Evaluation of Tomato Germplasm for Flavor and Flavor-contributing Components

Flavor is one of the most highly demanded consumer traits of tomato at present. The lack of 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 comprised of 173 tomato genotypes from USDA repository with a wide genetic background. The TTA varied from 0.20% to 0.64% whereas the TSS ranged from 3.4% to 9%, indicating the existence of a good variation for these traits. Rinon118783, 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 have 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 perspective of other traits including fruit firmness, color parameters, lycopene and vitamin C. Information obtained from this study may be useful for tomato breeders aiming to improve tomato flavor.