Intraspecific variability of isozymes of the lichen Umbilicaria mammulata

Thalli of the lichen Umbilicaria mammulata (Ach.) Tuck, were collected from six geographically distinct locations and extracts of these were analyzed by isoelectric focusing to test for isozyme variability within and between sites. A total of 58 bands were resolved representing eight different enzyme systems; some enzymes exhibited mostly constant electromorphs, and the remainder were highly polymorphic with many variable bands. Other enzyme systems were not reliably detectable in U. mammulata. Sums of squares agglomeration and principal-components analysis of the molecular data showed the existence of distinct groups corresponding to sets of thalli collected at each of the collection sites. There was a positive correlation between the phenctie distance between sites, based on isozyme distribution, and physical intersite distance.