Do tomatoes on the plant behave as climacteric fruits?

Abstract

I considered the possibility that changes in fruit photosynthesis obscure the occurrence of the climacteric rise in respiration in tomato fruits attached to the plant. Internal CO2 and ethylene concentrations in tomatoes (Lycopersicon esculentum Mill. cv. OH 7814) were analyzed after direct sampling through polyethylene tubes implanted in the external pericarp. Fruits which were shaded with aluminium foil contained up to 60 ml 1−1 CO2, until the internal ethylene concentration exceeded 1 μl l−1, when CO2 concentration declined to below 40 ml l−1; the CO2 concentration in fruits exposed to light only occasionally exceeded 40 ml 1−1. The internal CO2 concentration of detached fruits first declined and then increased along with ethylene concentration, as expected for the climacteric. Detached green fruits under continuous low photosynthetic photon flux density (100 μmol m−2 s−1) contained almost no internal CO2 and produced no CO2. Changes in photosynthesis and an associated CO2‐generating system in green fruits are thought to obscure the climacteric rise in tomato fruits developing on the plant.