Seasonal development of female strobilus of stone pine (Pinus pinea L.)

Abstract

The stone pine (Pinus pinea L.) prevails as a fruit tree rather than as a timber tree. Therefore, maximizing cone crops must be a primary goal for breeding perfor- mance (Pardos and Abellanas, 1988). Establishment, by grafting, of clone banks from selected provenances is a valid way to progress (Magini, 1965). Precise knowledge of the 4 yr reproductive cycle of this species is necessary for an accurate evaluation of cone production and manipulation of the selected clones in the banks. The object of the research described herein was to examine the morphology of the female strobilus and to describe the phenology of the reproductive cycle from seed-cone bud initiation to appearance of the embryo.