Morphological and molecular variation in natural populations of Betula

Molecular variation within morphologically variable natural populations of Betula pendula Roth, (diploid) and Betula pubescens Ehrh. (tetraploid) was investigated using RFLP and RAPD techniques. RFLP analysis of rDNA showed a high degree of polymorphism within and between individuals of both cytotypes in spacer length variation. Analysis of randomly amplified genomic DNA fragments, within one population, showed little differentiation between cytotypes. In East Anglian populations, diploid and tetraploid Betula are distinct neither on the basis of morphological nor molecular characters