Juglans regia L. sprout depends on the carbohydrate mobilization from the parenchyma cells into the buds located in the upper portion of the twigs. The objective of this work was to contribute to the walnut tree sprout acrotony mechanism, in temperate climate, through the activity of alpha-amylase (EC 3.2.1.1), and Sucrose Phosphate Synthase (SPS - EC 2.4.1.14) mensuration, related to carbohydrate mobilization, during the dormancy period. From September to March, five one-year-old twigs were monthly sampled around. In April, close to budbreak, three samples were accomplished. The twigs were divided in apical, sub-apical, and base, and separated in bark, buds and wood (xylem). The average time of bud break in controlled conditions (25ºC), water content, and activity of the above mentioned enzymes were determined. The results showed that the sprout gradient develops itself during ecodormancy period, and it is related with the alpha-amylase activity; the relationship of the SPS activity with this gradient is not evident.
alpha-amylase; sucrose phosphate synthase; Juglans regia
