Carbon Translocation in the Tomato: Effects of Fruit Temperature on Carbon Metabolism and the Rate of Translocation

The effects of fruit temperature on the rate of carbon translocationand on the contents of the major carbon metabolites in the experimentalfruits were investigated. Carbon import, which was inverselyproportional to fruit size, was inhibited by fruit cooling (5°Cand enhanced by fruit warming (35°C) when compared withcontrols (25°C); furthermore, there was net export of carbonfrom the largest cooled fruits. The carbon translocation rateswere related both to the rates of accumulation or depletionof starch and insoluble residue and to the concentration ofsucrose in the fruit. The possible dependence of the rate oftranslocation on a gradient of sucrose concentration betweensource and sink is discussed.