Estimation of gene flow into two seed orchards of loblolly pine (Pinus taeda L.)

Summary Multilocus allozyme markers, which were present in background stands but not in two seed orchards, enabled estimation of gene flow into two seed orchards of loblolly pine. Estimates averaged 36% in two orchards over three years. When pollen pool frequencies in the background stands were used rather than gene frequencies in the non-orchard trees, the estimates averaged 60%. In one year, trees in the row on the edge of one orchard received significantly more pollen from background stands. Estimates of gene flow between the two 2-ha orchards average 10%. Implications of the observed levels of gene flow are discussed in terms of population genetics and seed orchard management.Scientific Contribution No. 1285 from the New Hampshire Agricultural Experiment Station. This work was part of McIntire-Stennis Project 11 Allozyme studies of coniferous forest tree populations