Znaczenie zmienności genetycznej dla ochrony zasobów genowych cisa pospolitego w Europie

The genetic variation is considered to be a key factor for long−term survival of the species. The recognition of the existing genetic diversity is the preliminary phase in development of an effective strategy for conservation of forest tree species gene pools. Taxus baccata L. with a wide but scattered distribution in Europe is an example of rare and endangered species that needs both ex situ and in situ protection. The increase in fragmentation and isolation of populations and reduction in effective population size can cause erosion of the gene pool through increased genetic drift, increased inbreeding, reduced gene flow and decreased migration rate. As a result, local populations may be responsible for the loss of genetic variation, hence a decrease in their viability and adaptability. A few genetic analyses based on isozymes and DNA markers indicate that the yew, both in Poland and in other regions of Europe, is characterized by high levels of genetic variation within populations and moderate genetic differentiation between populations.