Identification and Mapping of QTL Affecting Antioxidant Compounds in Cherry Tomato, Poster Board #365

Antioxidant compounds such as lycopene, beta-carotene, ascorbic acid, and anthocyanin are important fruit quality traits in cherry tomato (Lycopersicon esculentum Mill.). Our objectives were to identify RAPD markers associated with QTL affecting three antioxidant compounds including lycopene, beta-carotene, and ascorbic acid in an F₂ population from the cherry tomato cross of CNB106 (low antioxidant compounds) x LA3538 (high antioxidant compounds) grown in a greenhouse, and then, place these markers linked to antioxidant compound QTL in a genetic linkage map constructed using the F₂ population of the cross. Continuous frequency distributions for three antioxidant compounds were observed in the greenhouse population indicating quantitative inheritance for the fruit quality traits. A total of 23 RAPD markers, seven obtained from CNB106 and 16 obtained from LA3538, were identified to be significantly associated with QTL affecting the three antioxidant compounds in the greenhouse population based on simple linear regression and interval mapping. Three CNB106-derived and four LA3538-derived markers, located on four different linkage groups of the linkage map, were significantly associated with QTL for lycopene in this population. We detected two CNB106-derived and eight LA3538-derived markers associated with QTL for beta-carotene in the population and placed these markers on three linkage groups of the cherry tomato map. One CNB106-derived and three LA3538-derived markers significantly associated with ascorbic acid QTL were mapped on two linkage groups of the map. After validating the associations of markers with QTL for antioxidant compounds in different populations and environments, these validated markers can be used in cherry tomato breeding programs for developing new cultivars having high antioxidant compounds.