| Antioxidants may help prevent some chronic diseases such as cancer, arthritis, and heart disease. A tomato introgression line population that from the wild species Lycopersicon pennellii (= Solanum pennellii ) in the background of the domesticated tomato, (Lycopersicon esculentum = Solanum lycopersicum), was used to identify quantitative trait loci (QTL) for nutritional and antioxidant contents. The concentration of ascorbic acid, total phenolics, lycopene and beta-carotene, and the total antioxidant capacity of the water-soluble fraction (TACW) were measured. A total of 20 QTL were identified. Some of these QTL (ao6-2, ao6-3, ao7-2, ao10-1, aa12-4, phe6-2, and phe7-4) increased levels as compared to the parental line. The traits studied displayed an environmental interaction as only 35% of the water-soluble antioxidant QTL were consistent over at least two seasons.;We investigated two additional phenotypes associated with the introgressed segment present in IL5-4: clear veins of the leaves and a measurable increase in plant height. The tomato mutant obscuravenosa ( obv), contains chloroplasts in cells around the vein, and thus, veins appear as dark as the surrounding leaf tissue. Among tomato cultivars, the obv allele is common in processing varieties, but is otherwise rare. The obv locus was mapped to chromosome 5 which also contains a quantitative trait locus (QTL) for plant height, which cosegregates with a paralog of the determinate self-pruning (sp) gene. Our data suggest that the prevalence of obv in nearly all processing varieties may have resulted from its tight linkage to a QTL conferring a more compact, and horticulturally desirable, plant habit.;We used a half di-allele design to study antioxidant QTL associated with L. pennellii introgressions; IL4-2, IL5-4, IL5-5, IL7-2, IL7-4, IL10-2 and IL10-3. We found the phenolic and antioxidant content in double introgressions to be increased in a less than additive manner. In contrast, ascorbic acid content was controlled in a dominant or overdominant fashion. We observed an increase in ascorbic acid of 83% associated with IL10-3x4-2, a 33% increase in phenolic content in IL7-2x10-3 and up to a 72% increase in antioxidant capacity in 1L7-2x5-4. The high antioxidant phenotype of IL7-2x5-4 was significant in both years of the study. |
