Pleiotropic Effects Associated with the Chlorophyll Intensifier Mutations high pigment and dark green in Tomato

Abstract

Abstract The chlorophyll intensifíer mutations high pigment (hp) and dark green (dg) of tomato (Lycopersicon esculentum Mill.) were analyzed for their effects on fruit and vegetative characters. These mutations are nonallelic, and differences between them are primarily quantitative. Both mutations increased Vitamin C content at all stages of fruit development, and more than 90% was present in the reduced form in the mature-green and fully ripe mutant types and in normal fruit. Ascorbate levels in all fruit portions were increased by hp and dg, with the largest increase occurring in the outer pericarp. Chlorophyll in outer pericarp tissue of mutant fruit was increased 166% by hp and 320% by dg. Mutant fruit were smaller and more elongate than isogenic normal controls, but ripening was unaffected by either mutation. Vegetative and reproductive development were retarded by both chlorophyll intensifier mutations. The hp and dg mutations significantly reduced total leaf area, internode length, and whole plant fresh and dry weight, but did not reduce the number of nodes present at a particular stage of development. The effects of dg were always quantitatively greater than for hp. The similarity of effects associated with these 2 nonallelic mutants suggests that pleiotropy rather than close linkage accounts for the multiple effects of these genes.