Pyrolysis-gas-liquid chromatography of fungi: Numerical characterization of species variation among members of the Aspergillus glaucus group

Principles of numerical analysis were applied to the interpretation of pyrolysis-gas-liquid chromatography (PGLC) data for characterizing species variation among three strains each of four species of theAspergillus glaucus group. Similarity values for the strains were calculated by comparing the number of peaks in which two strains agreed or disagreed. These data indicate that numerical analyses of pyrochromatograms were closely correlated with conventional taxonomic placement of the taxa with the exception of several intergrading or interbridging forms. Thus, a fundamental unity of these strains can be discerned at the chemical level by PGLC analysis. This unity stems from the similar chemical composition of these organisms, and deviation from this basic composition imparts to these strains their uniqueness and thus permits their delineation into distinct entities or pyrotypes based on the peak pattern of the pyrochromatograms.