© 2006 Heron Publishing—Victoria, Canada
Preformation in vegetative buds of Prunus persica: factors influencing number of leaf primordia in overwintering buds
D. Gordon (1, 2), C. Damiano (3) and T. M. DeJong (1)
1. Department of Plant Sciences, Mail Stop 2, University of California at Davis, One Shields Avenue, Davis, CA 95616-8780, USA / 2. Corresponding author (gordon@ucdavis.edu) / 3. Istituto Sperimentale per la Frutticoltura, Via Fioranello 52, 00134 Roma (RM), Italy / Received February 11, 2005; accepted June 24, 2005; published online January 15, 2006
Summary
We investigated the influence of bud position, cultivar, tree age, tree carbohydrate status, sampling date, drought and light
exposure on the number of leaf primordia formed in dormant vegetative peach buds (Prunus persica (L.) Batsch) relative to the number of primordia formed after bud break (neoformed). During winter dormancy, vegetative
peach buds from California and Italy were dissected and the number of leaf primordia recorded. Between leaf drop and bud break,
the number of leaf primordia doubled from about five to about 10. Parent shoot length, number of nodes on the parent shoot,
cross-sectional area of the parent shoot, bud position along the parent shoot and bud cross-sectional area were correlated
with the number of leaf primordia. Previous season light exposure, drought and tree carbohydrate status did not affect the
number of leaf primordia present. The number of leaf primordia differed significantly among peach varieties and tree ages
at leaf drop, but not at bud break. Our results indicate that neoformation accounted for all shoot growth beyond about 10
nodes. The predominance of neoformed shoot growth in peach allows this species great plasticity in its response to current-season
conditions.
Keywords:
bud dissection, dormancy, growth habit, neoformation, nodes.
