Promotion of ethylene evolution and ripening of tomato fruit by galactose

Mature green tomato fruit (Lycopersicon esculentum Mill. cv `Rutgers') were infiltrated with 0.5 milliliters of sterilized, distilled water alone, or containing enough glucose or galactose to allow for a concentration of 400 micrograms per gram fresh weight after infiltration. All fruit showed a transient peak of ethylene production within 6 hours due to the slight wounding by vacuum infiltration. In addition, galactose-treated fruit underwent a temporal increase in ethylene production after 25 hours, whereas, the glucose and H₂O-control fruit did not. Furit infiltrated with galactose subsequently produced ethylene and ripened substantially earlier than glucose or H₂O-control fruit.