Abstract
An isogenic line, differing from ‘New Yorker’ tomato (Lycopersicon esculentum Mill.) by being homozygous for the crimson gene (ogc ), had 60% less provitamin A due to reduced β- and γ-carotene.
A nutritional study was initiated to determine which carotenoids found in tomato result in decreased lipid oxidation ex vivo. To compare the carotenoids in a human diet without the use of purified supplements, tomatoes expressing nonfunctional enzymes in the carotenoid pathway were used. Tomato lines carrying the genes t, B, ogc, Del, or r were grown to produce fruit containing with high levels of prolycopene, beta-carotene, lycopene, or delta-carotene respectively, or low total carotenoids in r. Juices were processed from these lines and used in a dietary intervention study. Plasma samples were drawn before and after consumption of each juice. These samples were subjected to a battery of tests to analyze the contribution of carotenoids to the total lipid antioxidant status. Results of these tests are discussed.
Abstract
Seven mutant strains of tomatoes, crimson (ogc), high beta-carotene (B), low total (yellow r), ‘Snowball’ (yellow r), apricot (at), high pigment (hp), ‘Jubilee’ (tangerine, t), and the check cultivar ‘Rutgers’ were surveyed to determine the effects of these fruit pigment mutants on leaf pigments. Chlorophylls a and b, beta-carotene, lutein, violaxanthin, lutein 5,6-epoxide, and neoxanthin were separated chromatographically and quantities were determined spectrophotometrically. Significant differences among strains were found in chlorophylls and beta-carotene levels. Xanthophyll differences were, generally, nonsignificant. A definite pattern of gene effects was suggested. The apricot strain produced the highest levels of chlorophylls and beta-carotene in the leaves; one of the r strains, ‘Snowball’, the lowest.
Parents, F1 and F2 generations involving apricot, yellow (low total), crimson, and normal were analyzed to determine whether these leaf pigment differences could be related to these particular genes. Apricot significantly increased chlorophyll and beta-carotene levels as suggested in the survey. Yellow in a variable background, however, did not lower these pigments significantly.
Pigment synthesis in tomato leaves and fruits was discussed in relation to the gene effects inferred in the survey and the specific gene effects demonstrated in the segregating populations.
Continued and mounting evidence of the health benefits provided by carotenoid and anthocyanin pigments has increased public interest in dietary sources of these important phytonutrients. Tomatoes (Lycopersicon esculentum) are the primary dietary contributor of lycopene and an important source of beta-carotene. A collection of tomatoes containing the genes hp-1, dg, ogc, Ip, B and Af that are known to affect carotenoid and anthocyanin levels have been analyzed using HPLC. Levels of lycopene, beta-carotene, phytoene, and phytofluene have been determined in these accessions. Accession LA 3005, containing the dg gene, had the highest lycopene levels of the accessions analyzed (14 mg/100 g fresh wt.). A rapid HPLC method for quantitation of carotenoid levels from tomato fruit has been developed. “Heirloom” black and purple tomatoes have also been included in the accessions analyzed and have carotenoid levels comparable to cultivated red tomatoes. Anthocyanin presence has been confirmed only in the accessions LA 1996 (Af) and in some fruit of segregating plants from LA 3668 (Abg). Total monomeric anthocyanin content of LA 1996 as measured by the pH differential method is estimated to be 5.6 mg/100 g in the outer pericarp tissues and 18.6 mg/100 g in the skin tissue.
parents in additional hybrids because of the combinations of disease resistance genes and fruit-quality traits along with the ogc gene. ‘Mountain Regina’ is a vigorous, determinate plant ( sp gene) similar in height to that of ‘Mountain Fresh’ and
, 2002 ). Manipulation of germplasm by breeding techniques is the most common means for increasing the lycopene content of fruit ( Lester and Crosby, 2002 ). Several genes are available to increase lycopene, including the crimson (og^c) gene ( Stommel