Dormancy in vegetative buds of peach: relation between carbohydrate absorption potentials and carbohydrate concentration in the bud during dormancy and its release

The absorption of sucrose and sorbitol by the bud and the stem of Prunus pe rsica was evaluated during the rest period. The utilization of p-chloromerc uribenzenesulfonic acid (PCMBS), an inhibitor of sucrose transporter, allow ed estimation of the active absorption of sucrose in different isolated org ans (bud, bud's underlying tissues and stem). It was assumed that the sink capacities of tissues depended on their potential to absorb carbohydrates b y active transport. Endogenous carbohydrate levels in the tissues were also measured. In the bud, the qualitative and quantitative distribution of car bohydrates could be related to the absorption potential of the bud. During dormancy, the bud exhibited a low absorption potential and increased its su crose concentration by starch hydrolysis. Soluble sugars accumulated during winter. During dormancy release, the bud was able to absorb carbohydrates allowing carbon storage. The data presented led to the proposal of a scheme of events occurring during bud dormancy and its release. (C) 1999 Elsevier Science B.V. All rights reserved.