Temperature Inhibition of Carotene Synthesis in Tomato

1. Seven different pigment strains of tomato were studied. In each type a number of excised fruits were matured at either 23.5⚬C. or 32.0⚬C. and the quantities of phytoene, phytofluene, α-carotene, β-carotene, ζ-carotene, ψ-carotene, prolycopene, δ-carotene, γ-carotene, neurosporene, and lycopene were determined. 2. With the exception of β-carotene and possibly prolycopene, production of all of the pigments and polyenes measured was reduced at 32⚬C. Some pigments appeared to be more sensitive to the higher temperature than others. Lycopene synthesis was drastically inhibited at 32⚬C. in every strain which produced this pigment. 3. Beta-carotene synthesis was not inhibited at 32⚬C. in the standard red tomato. When the pigments of this type were enhanced by the introduction of the high pigment factor (hp), the enlarged β-carotene fraction was not temperature sensitive. In the Tangerine type, where very little β-carotene is produced, no inhibition of its synthesis could be demonstrated. In these strains, β-c...