Breeding for Increased Ascorbic Acid Content in Tomatoes

Abstract

1. A negative correlation between ascorbic acid content and fruit size usually was observed in these studies. Observations were made on the species Lycopersicon peruvianum, L. pimpinellifolium, L. esculentum, and the segregating populations of crosses between L. esculentum and L. pimpinellifolium and L. esculentum by L. hirsutum. In fourteen segregating populations derived from crosses between very small-fruited selections of high ascorbic acid content with large-fruited commercial varieties of low ascorbic acid content, a significant negative correlation of approximately -0.45 between fruit size and ascorbic acid content was observed. No constant relationship between ascorbic acid content and percentage of dry matter, lycopene, or β-carotene content was observed. 2. Selections with a higher ascorbic acid content than the high ascorbic acid parent have been obtained in advanced generations of segregating populations. It appears that many genes are involved in the inheritance of a high ascorbic acid content. 3. Selections with an average fruit size of 150-160 gm. and an ascorbic acid content of 530-560 μgm/gm have been obtained. Such selections have fruit size slightly smaller than commercial canning varieties but contain about twice as much ascorbic acid. 4. L. peruvianum selections with an ascorbic acid content as high as 1600 μgm/gm have been obtained. This content of ascorbic acid is one and one-half times greater than that found in any red-fruited selection and from four to five times greater than that of commercial varieties. 5. A rapid modified method of analysis for ascorbic acid has been described.