Phenetic analysis of genera of the Saprolegniaceae (Oomycetes)

Abstract

Phenetic analyses of the 20 genera interpreted to belong to the family Saprolegniaceae (Saprolegniales, Oomycetes) were performed to improve understanding of generic morphology, similarities and dissimilarities, and character utility. A primary objective was to establish generic data of reliable comparability, in which each genus may be compared with every other genus for each character utilized. Using a data set of 24 stable characters visible with the light microscope, factored into character states, various similarity and distance matrices were generated. These proximity matrices were entered into clustering programs to derive corresponding phenograms. The phenogram presented depicts well the generic alignments based on overall morphological resemblance. Phenetic groupings and subgroupings evident in this phenogram are discussed, as well as their character bases. Also, differences between generic groupings of this phenogram and groupings in or inferred from more traditional literature are considered.