Electrophoretic Evidence of Reticulate Evolution in the Appalachian Asplenium Complex

The Appalachian Asplenium complex consists of six fertile species: three diploids and their three allotetraploid derivatives. This reticulate evolutionary pattern, originally proposed on the basis of morphological and cytological evidence, was later corroborated by analyses of flavonoid composition. Presented here are data from starch gel electrophoresis of 11 enzyme systems, coded by 15 interpretable loci, which are highly consistent with the proposed relationships in the Appalachian Asplenium complex. The diploids are strongly differentiated (genetic distance (D) = 0.67 to 1.30); each diploid possesses unique alleles at several loci. Each allotetraploid expresses the heterozygous, or less often homozygous, enzyme phenotypes expected for combinations of parental alleles at most loci. Exceptions are the expression of a novel PGI-2 allele and the loss of expression of parental IDH alleles in both allotetraploids.