ブドウ果実の着色に関する研究(第3報) : デラウェア種果実の色素形成に及ぼすジベレリン処理の影響

This study was made on the influence of dippings of Gibberellic acid (G.A.) applied to the flower clusters at 14 days before and 10 days after full bloom on the pigmentation of Delaware grapes.
1. G.A. treatment induced parthenocarpic development of berries and promoted the maturation by more than two weeks.
2. Anthocyanin contents of treated berries increased at much higher rate than that of nontreated berries in their ripenning periods. And regression equations for anthocyanin contents and sugar contents of berries containing sugar in range 13 % to 20 % were as follows.
Dipped with G.A. : Y-452.6 = 187.0 (X-15.8)
Non treated : Y-312.9 = 79.8 (X-17.0)
X = Percentage of sugar content Y = Anthocyanin content shown by γ of KMnO_4/10<cm>^2 skin area
Consequently clusters dipped with G.A. had obviously deeper skin color of reddish purple at the optimum stage of sugar accumulation for picking as compared with non-treated clusters.
3. G.A. treatment had little effect on the relationships between chlorophyll and sugar contents of berries and between titratable acid and sugar contents of them.