GENETIC-VARIABILITY IN LARCH LARIX SUKACZ EWII DYL IN THE SOUTHERN URALS .2. LEVELS OF ISOZYME VARIATION IN NATURAL-POPULATIONS

Through an analysis of 20 isozyme loci specifying 12 enzyme systems, t he level of intra- and interpopulation variation in Larix sukaczewii D yl. in the southern Urals was studied. Two hundred trees from four pop ulations located 40-300 km apart were studied. Of 20 loci, nine proved to be polymorphic (Lap-2, Aat-1, Aat-2, Aat-3, Aph-2, Mdh-2, Mdh-3, S kdh-1, Dia-1); 11 loci were monomorphic (Lap-1, Aph-1, Mdh-1, G-6-Pdh- 1, Sod-1, Sod-2, B-Pgd-1, Gdh-1, Dia-2, Fdh-1, G-2-dh-1). The observed heterozygosity was H-o; while the expected heterozy gosity was H-e. T he proportion of polymorphic loci constituted 0.33 +/- 0.08 (95% crite rion of polymorphism) and 0.67 +/- 0.07 (99% criterion of polymorphism ); the average number of alleles per locus was 1.15 +/- 0.03. The esti mates obtained are lower than those reported for other larch species.