Figure 1.

Simplified version of the carotenoid biosynthetic pathway in pepper fruit and putative correspondences with quantitative and qualitative organ color loci identified in the Solanaceae revealed by this study. The metabolic intermediates of the carotenoid pathway and structural genes responsible for their catalysis are shown, with the exception of the conversion of lycopene to δ-carotene by lycopene ɛ-cyclase. Putative associations between these genes and previously defined qualitative (Xa, l2, B) and quantitative (fc1.1, fc2.2, fc4.2, fc10.1) loci in tomato, potato (Y), and pepper (pfc6.1, rc3.1, rl3.1, rh4.1), suggested by data from this study and shown in Fig. 2 are summarized. Previously defined identities (phytoene synthase–yellow-flesh and lycopene ɛ-cyclase–Del) in tomato and correspondences in pepper (capsanthin capsorubin synthase–Y) are not shown. The color of the intermediate is indicated in brackets: [y] = yellow, [or] = orange, [y-o] = yellow-orange, and [r] = red.