MORPHOLOGICAL AND MOLECULAR VARIATION IN NATURAL-POPULATIONS OF BETULA

Molecular variation within morphologically variable natural population s of Betula pendula Roth. (diploid) and Betula pubescens Ehrh. (tetrap loid) was investigated using RFLP and RAPD techniques. RFLP analysis o f rDNA showed a high degree of polymorphism within and between individ uals of both cytotypes in spacer length variation. Analysis of randoml y amplified genomic DNA fragments, within one population, showed littl e differentiation between cytotypes. In East Anglian populations, dipl oid and tetraploid Betula are distinct neither on the basis of morphol ogical nor molecular characters.