Fig. 2.

Chromosome number of diploid Betula nana (A: 2n = 2x = 28), triploid hybrid (B: 2n = 3x = 42) and tetraploid B. pubescens (C: 2n = 4x = 56). The chromosomes were isolated from leaf buds and stained with DAPI. Scale bar = 2 µm.