Relationships among five populations of European black pine (Pinus nigra ARN.) using morphometric and isozyme markers

Five European populations belonging to 3 subspecies of Pinus nigra ARN. (ssps. nigra, salzmanii, laricio) were analysed for 4 morphometric seeds characters (length, width, wing scar and weight/10 seeds) and for 23 isozyme loci. Significant differences were detected among the populations for the morphometric markers. Five isozyme systems (PGM, MDH, B-PGD, SOD and EST) presented diagnostic loci that allowed the identification of Corsican population and others. Moreover, statistically significant differences among allele frequencies were found using aconitase (AGO) glutamate oxaloacetate transaminase (GOT) and esterase (EST) isozyme systems. The greatest amount of the total genetic diversity detected was localized within the populations. Genetic heterogeneity among populations indicated that only 30.9% of the total genetic diversity was interpopulations. The dendrogram obtained using genetic distances among populations indicated the existence of 3 groups, corresponding to the 3 subspecies. This data clearly pointed out that the Corsican population is the most distant, with relative lack of genetic variation, probably due to its geographic isolation.