The genetic population study of Balkan Silver Fir (Abies alba Mill.)

BackgroundandPurpose:Silverfir(AbiesalbaMill.)isoneofthemost importantforesttreespeciesintheWesternBalkanareafrombotheconomic and ecological aspect. Its distribution has for years been the subject of scientific research, the reason being that silver fir from these areas displays very interesting morphological and genetic differentiation. Material and methods: The development of modern methods and the use of nad5-4 marker have solved the problem of contact zones of silver fir originating from the Apennine and Balkan glacial refugia in the Western Balkan area. The objective of this study was to determine the boundary of gene introgression of silver fir derived from the Apennine and Balkan glacial refugia in the western Balkan populations with the use of isoenzymes. Twenty-four selected populations from Bosnia and Herzegovina and Croatia were investigated. Nine enzyme systems were studied, polymorphicgenelociwerescoredandsoweretheirallelictypes.Theanalysisof generalgeneticparametersdidnotallowforanyconclusion,andneitherdid the analysis of genetic distances. For this reason, the allele distribution was analyzed. Results and Conclusions: Statistical analysis showed the separation of the populations from Croatia which belong to the group west of the contact zone.Inthepopulationsalongthecontactzoneandinthosefromtheeastern part,thegroupingdidnotshowanyregularityoranyclinalvariability.The mainreasonforthisisattributedto highecologicaldiversity,fragmentation and the occurrence of genetic drift. It can be concluded that silver fir originating from the Balkan refugium was more widely distributed in the past,butisnowconstantlyretreatinginrelationtothatoriginatingfromthe Apennines. Another hypothesis is that it may have reached southern Germany through a similar gene flow. The impact of the alleles originating from the Apennine refugium is also present in the eastern parts of Bosnia.