CARBOHYDRATE STATUS AND INVERTASE ACTIVITIES IN RELATION TO SURVIVAL AND WEAK DORMANCY OF THE LATENT BUDS IN PLATANUS-ACERIFOLIA WILLD

Changes in carbohydrate content. (starch, sucrose and glucose) and in invertase activities have been studied during a vegetative cycle. Two zones (node and internode) were harvested from three-year-old branches of Platanus acerifolia. Starch hydrolysis occurred in November and De cember while the concentration of soluble sugars (sucrose and glucose) increased. This hydrolysis was stronger at the node level than at the internode level. In February, the inverse carbohydrate conversion occ urred. After bud burst period (April), starch concentration decreased rapidly in the same way in both zones. The soluble sugars were found a t a low level. Starch synthesis began early in June when the first lea ves were mature. Soluble acid invertase activity was more important th an soluble alkaline invertase activity. At deep dormancy period (Novem ber), both sucrose concentration and acid invertase activity were stro ng. After this period, changes in sucrose content were inversely corre lated to changes in acid invertase activity. At the node level, the zo ne containing latent buds, sucrose was always present, which could all ow determination of the survival and the permanent growing capacity of the latent bud.