Family Outcrossing Rates of Pinus caribaea Morelet var. caribaea in Seed Orchard and Natural Populations

Family outcrossing rates of Pinus caribaea var. caribaea populations that differed in origin and management were estimated by using isozyme markers. The family outcrossing rates were estimated by (1)fixing the probability of pollen gene frequency (p); (2) allowing pollen gene frequency to vary among families. The estimates of family outcrossing rates for all the populations varied widely among families (clones of the seed orchard), ranging from 0.39 to 2.0. The average family outcrossing rates of both methods were greater than the

Family Outcrossing Rates of Pinus caribaea Morelet var. caribaea in Seed Orchard and Natural Populations

Family outcrossing rates of Pinus caribaea var. caribaea populations that differed in origin and management were estimated by using isozyme markers. The family outcrossing rates were estimated by (1)fixing the probability of pollen gene frequency (p); (2) allowing pollen gene frequency to vary among families. The estimates offamily outcrossing rates for all the populations varied widely among families (clones of the seed orchard), rangingfrom 0.39 to 2.0. The average family outcrossing rates of both methods were greater than the population multilocus estimates. The Standard errors of the multilocus estimatesfor individual families are much higher than those of population estimates. It seemed that keeping the pollen allele frequency p constant among parent trees was more realistic than allowing it to vary. The regressions of outcrossing-pollen allelefrequency on ovule genotype varied widely among loci in all populations with the regression coefficient rangingfrom -0.199 at PGD-b in the seed orchard to 0.212 at IDH in MBJ managed as seed stand. Fixation indices for the maternal parents rangedfrom -0.089 in MBJ to -0.41 in seed orchard with an overall mean of-0.21. All of these values were negative and were not significantly different from zero. All maternal F values were not significantly different from the corresponding equilibrium F values averaged 0.016.