Genetic variability of tall junipers (Juniperus excelsa Bieb.) on the northern and southern boundaries of their natural distribution

The genetic structure, subdivision, and differentiation of six populations of tall junipers ( Juniperus excelsa Bieb.) in the Crimean Mountains and one population in Lebanon were investigated using 18 polymorphic allozyme loci as genetic markers. A high level of genetic variability of J. excelsa was established at the northern and southern boundaries of their natural habitats. The mean values of the main indicators of genetic polymorphism were P 99 = 1.000, A = 3.167, H E = 0.370, and H O = 0.405. The subdivision and differentiation of populations were low (F ST = 0.032, D N = 0.026), indicating the similarity of their gene pools.