COMPARISON OF POLYMORPHISM AND PHENETIC VARIABILITY AS DETERMINED BY THE STUDY OF HYDROLASES AND OXIDOREDUCTASES IN 2 CULTIVATED MUSHROOMS, AGARICUS-BISPORUS AND PLEUROTUS-CORNUCOPIAE

Iraçabal, B., and Labarère, J. 1993. Comparison of polymorphism and phenetic variability as determined by the study of hydrolases and oxidoreductases in two cultivated mushrooms, Agaricus bisporus and Pleurotus cornucopiae. Experimental Mycology 17, 90-102. The isozyme polymorphism and phenetic variability of two cultivated mushrooms Agaricus bisporus and Pleurotus cornucopiae were compared by studying the activity of five enzymes belonging to two different functional groups: (i) oxidoreductases: peroxidases (POD), tolidine-reacting enzyme phenoloxidases (TRE), and dopa-reacting enzyme phenoloxidases (DRE); and (ii) hydrolases: butyrate esterases and acetate esterases. Reproducibility studies showed that few variations were observed in the isozyme patterns and that the enzyme activities were conserved during at least 6 months of storage at - 20°C, except for POD activity which was stable for only 2 months. The same level of relative polymorphism was observed for each enzyme activity in the two species, although they present differences in their life cycle and their genetic background. The most polymorphic activities were found for the hydrolases, whereas the most conserved were POD and TRE, DRE having an intermediate level of conservation. These results indicated that enzyme polymorphism and phenetic variability seem to be correlated with the functional group of the enzyme rather than with the genus. The phenetic distances, as determined by numerical analysis, allowed discrimination among the 12 A. bisporus commercial strains in three cluster groups. In the case of P. cornucopiae, results showed a large variability between wild strains in accordance with their geographical origin, and that the two cultivars studied corresponded to two replicas of the same strain. © 1993 Academic Press. All rights reserved.