Effective number of pollen parents in clonal seed orchards.

A method for quantifying mating behavior in clonal seed orchards of forest tree species is presented. It involves the estimation of effective numbers of pollen parents from seed samples collected from individual ramets in such orchards. These effective numbers are variance effective numbers for populations of male gametes that are successful in uniting with ovules to produce viable seed. Three such effective numbers are defined for clonal seed orchards:N p (a) for male gamete populations for ramets within clones,N p (b) for male gamete populations for clones, andN p (c) for male gamete populations for entire orchards. Estimators for these effective numbers and for standardized variances of allele frequencies in the male gametic populations are presented. Expressions are also given for the confidence intervals for each of the three effective numbers. Estimates of these parameters and the corresponding confidence intervals for two seed orchards are presented and interpreted.