Enhanced Degreening of Apple Fruit by Jasmonates

Abstract

Airborne methyl jasmonate (MJ) can modulate apple fruit ripening, including the degreening process. Degreening of `Fuji' and `Golden Delicious' apples by jasmonates [jasmonic acid (JA) and MJ] in aqueous solution was investigated. JA and MJ applied by dipping apples in solutions of jasmonates for 2 min enhanced degreening during ripening at 20C. MJ was more effective at promoting degreening compared to JA. The minimum concentration of jasmonates required to promote significant degreening during the 2-week ripening period was 1 mM. Degreening of jasmonate-treated apples ripened at 4C progressed slower compared to apples ripened at 20°C. JA stimulated apple fruit ethylene production at concentrations as low as 10 μM. Jasmonates at 1 or 10 mM were more effective at accelerating the degreening process compared to 0.35 or 3.5 mM ethephon. Firmness, soluble solids content, and titratable acidity of `Fuji' apples were not significantly affected by jasmonate treatments. Peel injury occurred on apples treated with 10 mM JA or 3.5 mM ethephon.