ABSTRACT
Isozyme electrophoresis is a frequently used tool in systematics, genetics, and population biology. The technique has been widely applied in plant biology to study gene flow and genetic diversity, but the limited knowledge of fungal population genetics has made the application of isozymes in mycology controversial. The application of isozymes in fungal taxonomy and phylogeny may still be controversial, but several studies have used differences in isozyme patterns of fungi to clarify taxonomic problems at the species level. Isozyme characters are most often used as phenetic characters. The taxonomy of the fungi in the order Glomales forming arbuscular mycorrhizas is highly controversial. Isozyme data can be useful in species descriptions. In the redescription of Phytopthtoracitrophthora, isozyme data are included to support the morphological characters that can sometimes be difficult to assess. Isozymes are valuable as unweighted phenetic characters, but an evolutionary interpretation of isozyme data can be obtained by using them in phylogenetic reconstructions.
