The problem of classifying cultivars with special emphasis on oat (Avena) cultivars

Abstract

Oat cultivars, although superficially homogeneous, contain much variability and intergrade with one another. The same cultivar may vary from year to year, and from one locality to another in the same year. Existing methods of classification, which are mostly regional, are inadequate for worldwide application. It is stipulated that worldwide classification of oat cultivars in particular, and cultivars in general, be based on as many attributes as possible requiring the use of the techniques of numerical taxonomy.This paper demonstrates that there is no correlation and no conformity between existing systems of classification of oats and the phylogenies of the oat cultivars. Moreover the various specific and infra-specific taxa according to the different systems are recurrent in many pedigrees and clearly manifest the polyphyletic origin of the key characters of these taxa.Because of the lack of conformity between the genealogic relationships of the cultivars with any of the existing classifications, it is concluded that two independent goals in taxonomy of cultivated oats particularly, and taxonomy of cultivars in general, should be undertaken separately: (1) construction of genealogies, (2) classification and identification.