Beech (Fagus sylvatica L.) is one of the most important forest trees in Bosnia and Herzegovina in both economic and environmental terms. The total area of forest in which beech is present is approx. 1,652,400 ha. There is a proportionate need to plant new forests and produce genetically high quality seed and saplings. Biochemical analysis of the genetic structure of eight populations of beech using ten enzyme systems from 16 isoenzyme gene loci revealed significant differences between the populations analyzed. Variance levels were high in some gene loci, while in some populations monomorphism was recorded only for individual gene loci. The average number of alleles per locus ranged from 2.1875 to 2.5625, and the average number of genotypes per locus varied from 2.6875 to 3.2500. The multilocus genetic diversity at the population level ranged from 63.276 to 162.001, and the genofund diversity varied from 1.2708 to 1.3416.The average differentiation value obtained for all populations was fairly low (Dj=5.81), indicating a percentage of overall variance of about 94.194%.

The wild cherry (Prunus avium) has great and multiple importance. The fruits it produces are used for several purposes (as food for people, birds and other animals, as well as in phytotherapy). As many birds and mammals feed on the fruit of the wild cherry, it has the ability of dispersion over large areas in a very short time. It occurs from river deposits up to 1900 m/alt, while it is quite rare in the Submediterranean. Wild cherry grows as a solitary tree or in small groups, usually at the edge of the forest or within the forest in areas with more sunlight. The significance of the wild cherry is reflected in the high economic value of its wood, which makes it much demanded and popular, and thus endangered. The plant material was collected from 22 natural populations in Bosnia and Herzegovina. The fruit and leaves were collected from marginal or solitary trees, usually from the south-facing, outer sun-exposed parts of the tree crown. We measured the following fruit characteristics: fruit length (FL), fruit width (FW), fruit thickness (FT), seed length (SL), seed width (SW), seed thickness (ST), length of the stalk (LOS) and width of the stalk (WOS), and leaf characteristics: length of the petiole (LP), length of the leaf blade (LB), distance from the blade's base to the blade's widest part (BBW), width of the leaf blade (WB), insertion angle of the leaf venation (AV), number of leaf teeth on a 2-cm length (NT), blade width at 1 cm from the blade apex (WBA) and blade width at 1 cm from the blade's base (WBB). All statistical analysis of the data were made using the SPSS 15.0 package for Windows. The results obtained show the presence of a high level of intrapopulation, as well as interpopulation, morphological variability in the natural populations of the wild cherry which have been investigated. Analyses of population differentiation have not confirmed our expectations. Our results only indicate differentiation in the fruit size characteristics, but the indicators are very weak. The resulting high values of the regression coefficient in this research can serve to estimate the values of some features and characteristics without their measurement. The analyses of 16 morphological characteristics in 22 natural populations of the wild cherry in Bosnia and Herzegovina showed statistically significant differences between investigated populations. Differentiation in natural populations of the wild cherry was very low and identified only in fruit dimension characteristics.