CELL ENLARGEMENT AND CELL-SEPARATION DURING PEACH FRUIT-DEVELOPMENT

The increase in cell size and the activities of cell wall lytic enzyme s during fruit growth supported by the mesocarp cell enlargement have been studied in peach of the freestone cultivar Redhaven. Four growth stages (S1-S4) in peach fruit were observed. Cell enlargement and form ation of intercellular spaces in the mesocarp were directly correlated with the increase in fruit diameter. Cellulase and exopolygalacturona se showed the highest activity during the first stage of fast fruit gr owth (S1), while the endopolygalacturonase activity increased during t he last growth stage (S4), when the fruit reached its final size and r ipening started.