Effect of methyl jasmonate on in vitro strawberry ripening

Strawberry fruits (Fragaria x ananassa Duch.), cultivar Camarosa, were harvested at green inmature stages and grown in vitro in sucrose-containing solutions. The effect of exogenously added methyl jasmonate (JAMe, 50 mu M) on in vitro development and ripening of strawberry was evaluated through different parameters. A significant increase in respiratory activity and ethylene production was determined in white and pink strawberries treated with JAMe, while different responses were elicited from ripe and overripe fruits. A higher growth rate was found in JAMe-treated fruits, with a 55% weight gain against 33% for control fruits. A significant effect of JAMe treatment on strawberry color evolution was also observed by a stimulation of anthocyanin biosynthesis after 2 days of treatment and an accelerated degradation of chlorophyll a, chlorophyll b, and, to a lesser extent, beta-carotene and lutein.