Selection and Breeding for High β-Carotene Content (Provitamin A) in Tomato

High β-carotene concentration in tomato fruits has been obtained from selections of the cross [Baltimore x F1 (Rutgers x L. hirsutum P. I. 12644-5)]. One selection from this backcross generation produced an average content of 101 γ/gm. of crude carotene, of which 88% occurred as β-carotene. 2. Large-fruited, high β-carotene selections have been obtained, by further backcrossing to commercial varieties, at a frequency great enough to suggest that the number of major factors necessary to obtain high β-carotene, in addition to those present in commercial varieties is small. 3. β-Carotene appears to be produced at the expense of lycopene, since the total carotenoid concentration in the high β-carotene selection, is not increased over that of the red, low β-carotene parent.