Accumulation of 14C-Labelled Material from Foliar-applied 14C Sucrose by Tomato Ovaries during Fruit Set and Initial Development1

Abstract

A determinate cherry tomato (Lycopersicon esculentum Mill. cv Farthest North) was used to test whether fruit set involves mobilization of sucrose to the ovary, or whether mobilization occurs only after fruit growth commences. Following auxin treatment, average ovary fresh weight increased 0.4 mg and 3.6 mg during the first 24 and 36 hours, respectively. Radioactivity from foliar-applied 14C-sucrose was not significantly greater in auxin-treated ovaries than in water controls until 48 hours after treatment. Parallel data were obtained following pollination. Labelling with l4CO2 did not alter the response, nor did the time of labelling with 14C-sucrose. Thus, tomato fruit set per se does not appear to involve mobilization.