A Numerical Taxonomic Study of Phylogenetic and Phenetic Relationships in some Cultivated Oats, Using Known Pedigrees

Abstract

Baum, B. R. and L. P. Lefkovitch (Plant Research Institute and Statistical Research Service, Research Branch, Department of Agriculture, Ottawa, Canada) 1973. A Numerical Taxonomic Study of Phylogenetic and Phenetic Relationships in some Cultivated Oats, using known Pedigrees. Syst. Zool. 22:118-131.-The concordance between phenetics and and phylogenetics in 16 cultivars of oats has been examined through a series of taxometric procedures. Phylogenetic relationships have been established, firstly, from known pedigrees, i.e., the cladogram, which allow the coefficients of common parentage to be computed, and secondly, from the known dates of breeding. Phenetic relationship was assessed by different clustering strategies and by nonmetric multidimensional scaling, using the Gower similarity coefficient computed from a set of characters witll agronomic importance, from a set of characters without apparent agronomic value and from the union of these sets. The various methods were compared both by metric multidimensional scaling and single linkage clustering. The main finding is that phenetic relationships shown by the reduced sets of agronomic characters and nonagronomic characters fit best with the cladogram. However, the best of the various clustering procedures, here defined as that which disturbs the original relationships the least, coincides most closely with the genetical relationships. Our data suggest that it is impossible to reconstruct a true phylogeny from phenetic relationships, although some representations of the former may be similar to some of the latter.