RELATIONSHIP BETWEEN ABSCISIC-ACID (ABA) CONTENT AND MATURATION OF THE SWEET CHERRY

The changes in abscisic acid (ABA) content, ethylene evolution, and an thocyanin and sugar contents of the 'Satohnishiki' cherry fruit (Prunu s avium L.), and the effect of ABA application on its maturation and c oloring were investigated. 1. Among sugars in the fruit, glucose was t he highest in content followed by fructose and sorbitol. The total sug ar content increased greatly from 38 days after full bloom (DAFB), at which time a concomitant rise in anthocyanin accumulation was also not ed. 2. The ethylene evolution per gram fresh weight fell continuously from 17 through 31 DAFB. It increased slightly from 31 DAFB to 38 DAFB , after which it decreased again. In contrast, the ethylene evolution per fruit increased greatly from 31 DAFB. 3. The endogenous ABA levels of the pulp and peel were relatively high on 17 DAFB, but fell to low er levels by 31 DAFB. The ABA content in the pulp increased dramatical ly from 31 DAFB, while the level in the peel rose slightly from 31 DAF B and more rapidly after 38 DAFB. 4. ABA application to the fruit on 3 6 DAFB enhanced the total sugar and anthocyanin contents of the fruit. It is thus suggested that the ABA content may be related to the fruit growth rate, maturation and coloring of sweet cherry.