| Abstract
| - Vegetable cultivation favored the inclusion of pleasant aromas in the produce, whereas unpleasantaromas were selected against. Introgression lines, generated by hybridization of a cultivated tomato(Lycopersicon esculentum) to its wild relative L. pennellii, were used to map quantitative trait loci(QTL) that influence tomato aroma. A marked undesirable flavor was detected by taste panelists inL. pennellii fruits and was related to an introgressed segment from the short arm of chromosome 8.Analysis of the ripe fruits' volatiles of chromosome 8 introgressed lines revealed an up to 60-foldincrease in the levels of 2-phenylethanol and phenylacetaldehyde, as compared to the cultivatedtomato. This effect was associated with a 10 cM segment originating from the wild species. Although2-phenylethanol and phenylacetaldehyde have favorable contribution to tomato aroma when presentat low levels, phenylacetaldehyde has a nauseating objectionable aroma when present in levels >0.005ppm. The loss of the ability to produce high levels of phenylacetaldehyde contributed to thedevelopment of desirable aroma of the cultivated tomato. The findings provide a genetic explanationfor one of the aroma changes that occurred during the domestication of the tomato. Keywords: Tomato; Lycopersicon esculentum; L. pennellii; mapping; flavor; aroma; 2-phenylethanol;phenylacetaldehyde
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