Anatomical Aspects of Root Bud Development in Hoop Pine (Araucaria cunninghamii)

Abstract

Root bud development was studied in the severed, secondarily thickened, lateral roots of 20-year-old hoop pines (Araucaria cunninghamii Aiton ex D. Don). The buds arose adventitiously in the parenchyma of the proliferated pericycle at positions opposite the diarch primary xylem poles, although they were not associated with lateral roots. The buds had an orthotropic mainstem and juvenile leaf morphology and could thus be a useful source of material for vegetatively propagating elite hoop pines.