The mating system in a Scots pine clonal seed orchard in Poland

Abstract

The mating system of a clonal seed orchard of Pinus sylvestris L consisting of 32 clones was studied using allozyme marker loci. Single-locus estimates of outcrossing rate ranged from 0.907-1.106 (with a mean of 1.011), while the multilocus estimate was 0.987. The outcrossing rates of individual trees ranged from 0.840-1.208. The variance effective population size estimated for males was equivalent to 14 individuals. Some patterns of non-random mating were found. The level of inbreeding as measured by average fixation indices was low, both in the parental and the filial generations. The usefulness of Scots pine seed orchards in forest tree improvement has been discussed in the light of genetic efficiency.