Changes of Lipid Components During Dormancy in Blackberry Cultivars

Abstract

Changes in phospholipids, galactolipids, and fatty acid were determined in two cultivars of blackberries, `Triple Crown' and `Hull Thornless', during dormancy and budbreak. Under field conditions, `Triple Crown' required lower chilling units (CUs) than `Hull Thornless' to overcome dormancy. `Triple Crown' and `Hull Thornless' achieved full budbreak after receiving 600 and 1000 CUs, respectively. Under cold-temperature treatments, `Triple Crown' needed 400 CUs, while `Hull Thornless' needed 600 CUs at 4 °C to obtain 100% budbreak. The shoots kept at intermittent 6/24 °C (6 °C for 16 h, and 24 °C for 8 h) did not reach full budbreak even after receiving 1000 CUs. An increase in phospholipids and glycolipids was observed during the termination of dormancy. The increase in phospholipids occurred earlier than the increase in glycolipids. The percentage of 18:2 fatty acid decreased while 18:3 increased and there was approximately a five-fold increase in the 18:3/18:2 ratio observed at the time of budbreak. The increase in the 18:3/18:2 ratio could serve as an indicator of dormancy termination and growth resumption in blackberry.