THE RELATIONSHIP BETWEEN PECTINASE AND CELLULASE AND POST-HARVEST NEEDLE ABSCISSION IN BALSAM FIR (Abies balsamea (L.))

Abstract

Post-harvest needle abscission is a major challenge for the Christmas tree industry in Atlantic Canada. To further elucidate the physiological basis of needle loss in Balsam fir, experiments were conducted to investigate the possible link between certain hydrolytic enzymes and post-harvest needle abscission in balsam fir. This study focussed on the role of enzymes, pectinase and cellulase, in post-harvest needle abscission. Following harvest, cumulative cellulase activity increased over time prior to needle loss on both high and low needle retention duration (NRD) clones. Total cellulase activity of low NRD clone was much higher than that of high NRD clone. Pectinase does not affect needle abscission in this study. If cellulase activity is linked to post-harvest needle abscission, then inhibiting cellulase enzyme would reduce needle loss. Pre-treating branches with 2.5g 1-methylcyclopropene (1-MCP) enhanced needle retention.