Description:
<jats:title>Abstract</jats:title><jats:p>For the estimation of the GC‐content, we have elected representatives of single groups which have been formed by numerical evaluation of the relationships among the strains of the genus <jats:italic>Saccharomyces</jats:italic>. The estimated GC‐values for 48 strains of the genus <jats:italic>Saccharomyces</jats:italic> gave an average of 36.75 Mol%, standard deviation being 1.96. The variation range within the limit 35.0–39.0 corresponds to the normal distribution.</jats:p><jats:p>Between the strains of the genera <jats:italic>Zygosaccharomyces</jats:italic> and <jats:italic>Saccharomyces</jats:italic> was shown a low phenetic similarity. A low similarity in DNS base composition was found between the groups <jats:italic>“delbrueckii”</jats:italic> and <jats:italic>“fermentati”</jats:italic>. This shows that they are not related phylogenetically to each other but form a polyphyletic group. Although strains of the group <jats:italic>“bailii”</jats:italic> and <jats:italic>“rouxii”</jats:italic> are phenetically not much similar to the genus <jats:italic>Saccharomyces</jats:italic>, the DNA base composition falls into the range of <jats:italic>Saccharomyces</jats:italic>. On the contrary, the genus <jats:italic>Saccharomyces</jats:italic> appears to be homogeneous not only phenetically, but also on the basis of similarity of DNA base composition.</jats:p>