A Molecular Genetics Study of Silver and Downy Birches in Peatland and Paludified Forest Types in the Center of the East European Plain

Abstract

Taxonomic status of birches (Betula pendula, B. pubescens or their hybrids) is identified by molecular genetics assay of the ploidy level using SSR-markers in moist and peatland forest types. Studies are performed on experimental forest sites of the Institute of Forest Science in the center of the East European plain. B. pendula × B. pubescens hybrids accounted for 11% of the combined dataset. Thus, the birch hybrids are essential components of natural communities. We demonstrate for the first time that B. pendula is predominant, the hybrids are rare, and B. pubescens occurs sporadically on oligotrophic peat bogs. B. pendula grew in the canopy while B. pubescens and the hybrids grew in second story of moist blueberry pine forests. Identification of birch species using keys for the flora species is proven to be confusing due to the occurrence of different combinations of traits. All genetically identified B. pendula trees had twigs growing upwards, without pendulous traits.