XVI International Botanical Congess

Investigation of genetic variation in pubescent tree birch (Betula pubescens, tetraploid, European) and dwarf birch (B. nana, diploid, circumpolar) using molecular and cytogenetic methods. Genetic variation in pubescent birch is extensive when examined morphologically and this has been suggested to be the consequence of introgressive hybridization, whereby the gene flow can occur through interspecific hybridization and back-crossing of the hybrids. Genomic relationships between these two species have been determined by hybridization experiments where essentially species-specific DNAs have been identified, isolated and characterized. They will be used for identifying species origin of chromosomes in variable birches both naturally occurring and from crosses. The project should lead to a better understanding of genetical and evolutionary process in the genus Betula.