An investigation of the genetic variation in four fucales species using cellulose acetate electrophoresis

A cellulose acetate electrophoresis method was used to examine allozyme Var iation both within and between three members of the genus Fucus: F. spirali s, F. vesiculosus and F. serratus and Ascophyllum nodosum. Samples of algae were collected from two rocky shores, one sheltered and one exposed, 11 km apart and screened for allozyme variation at eight loci. Patterns of alloz yme variation at five polymorphic loci were successfully resolved. There wa s significant heterogeneity in allele frequencies between both the F. serra tus and F. spiralis populations from the two shores but not between the two F. vesiculosus populations. In the fucoids, there was an overall heterozyg ote deficiency within populations relative to Hardy Weinberg proportions an d F-IT values were high. There was little genetic differentiation between t he populations of each species, however Fucus serratus showed the greatest (F-ST = 0.0261) and F. vesiculosus the least amount (F-ST = 0.0058) of gene tic differentiation between shores. Based upon UPGMA clustering of Nei's ge netic identities, F. spiralis was the most genetically distinct and F. serr atus clustered with F. vesiculosus. Ascophyllum nodosum joined the main Fuc us cluster as an outgroup confirming that it is genetically quite distinct from the members of the genus Fucus. Based on our results we suggest that c ellulose acetate electrophoresis is a suitable tool for the elucidation of population genetic patterns in the brown algae.