Izozyme diversity of Phosphoglucose Isomerase, Phosphoglucomutase, Shikimate dehydrogenase and 6-Phosphogluconate dyhydrogenase of Fagus orientalis Lipsky in beech forests of Iran

Fagus is one of the most abundant and economically important genera of woody plants in the North of Iran. Izozyme diversity of Fagus orientalis Lipsky was investigated in 14 Iranian beech populations originating from the major part of distribution range of this tree species in Hyrcanian zone (Southern coasts of Caspian Sea). Enzyme variation of beech populations was studied using 5 isozyme Loci at 4 systems including Phosphoglucose Isomerase (PGI), Phosphoglucomutase (PGM), Shikimate dehydrogenase (SKDH), 6-Phosphogluconate dyhydrogenase (6PGD) by starch gel electrophoresis. Among 19 observed alleles, 12 rare alleles in 5 loci (less than 5% of the allelic frequency) and 10 specific area alleles (observed in less than 5 populations) were detected. Results indicated that all specific area alleles are rare ones too. Population Neka at elevation 900 m from sea level and Kheirud at elevation 2000 m from sea level showed the highest number of specific area and rare alleles. No area specific or rare alleles were found in population Gorgan at 2000 m from sea level. Observation of some geographical trends in alleles PGI-B/B and SKDH-A/B were couse of important ecological differences among the studied populations (from East far to West far and from lowest to highest limitation of beech forests in Iran).