HETEROGENEITY IN POLLEN ALLELE FREQUENCIES AMONG CONES,WHORLS, AND TREES OF TABLE MOUNTAIN PINE (PINUS PUNGENS)

Pinus pungens Lambert (Table Mountain pine) is characterized by serotinous cones that are borne several (two to five) per whorl. Sporophytic and gametophytic tissues from whorls collected in different canopy zones of eight trees were electrophoresed and surveyed for six allozyme loci. Pollen allele frequencies received by individual trees, whorls on trees, and cones in whorls were estimated and used to estimate outcrossing rates and the distribution of genetic diversity within and among each level. Significant differences in pollen allele frequencies were detected at all levels, indicating that the genetic composition of the pollen pool available to different female strobili is heterogeneous. The fine-scale genetic structure in the seed pool is a record of past reproductive events and is the precursor to genetic structure in the next generation.