Outcrossing rates in a natural stand and in a seed orchard of Pinus peuce

Abstract

The mating system parameters were studied in a natural stand and in a seed orchard of the Balkan endemic, Pinus peuce Griseb. by means of isozyme gene markers. The results indicate that the multilocus estimates of the outcrossing rates are low relative to other widespread conifers but concord to these reported for other pine species with limited area of distribution. No significant differences were detected between the natural stand and the seed orchard estimates. Multilocus estimates of outcrossing rate were within the range 0.77-0.79, while mean single-locus estimates were lower (0.69-0.73). The results indicate that at least 20% of the progeny of Pinus peuce is due to self-fertilization. Possible reasons for the results observed and the implications for tree breeding and gene conservation are discussed.