MATING PARAMETERS IN JUGLANS-NIGRA L SEED ORCHARD SIMILAR TO NATURAL-POPULATION ESTIMATES

Electrophoretic data for eight polymorphic loci from six enzyme system s in black walnut (Juglans nigra L.) nut collections from a Missouri h alf-sib progeny test, an Indiana seed orchard and a natural population in southern Illinois revealed very high levels of variation (75.0% to 87.5%), mean heterozygosity (0.198 to 0.215) and outcrossing rates (0 .880 to 0.928) in all there populations. Mating parameters from seed o rchard populations were not significantly different from those of the natural population. The mean fixation index was less than 0.1 in all t hree populations suggesting very low rates of inbreeding in this speci es in seed orchards as well as in a natural setting.