Mating system and genetic diversity in natural populations of knobcone pine (Pinus attenuata)
Burczyk, J.; Adams, W.T.; Shimizu, J.Y.
Forest Genetics 4(4): 223-226
Mating system and genetic diversity were investigated in 3 natural populations of P. attenuata, located at the northern limits of the species range, near the California-Oregon border, USA. Multilocus estimates of outcrossed progeny (tm), based on isozyme electrophoresis data for 11 enzyme systems, were high in all populations (mean tm = 0.927). Although tm values were not significantly heterogeneous over populations, they varied in magnitude consistent with stand density, i.e. tm decreased with increased spacing between trees. Mean single-locus estimates of t differed only slightly from tm, suggesting that there is little inbreeding other than selfing, despite expected clustering of family members in these stands.