Anionic peroxidase isoform profiles from calli and barks of pear cultivars and of the quince rootstock EM A DEMETRIOS PETKOU1, GRIGORIOS DIAMANTIDIS2 and MILTIADIS VASSILAKAKIS1 1 Laboratory of Pomology, and 2 Laboratory of Agricultural Chemistry, School of Agriculture, Aristotle University, 54124 Thessaloniki, Greece   Abstract The anionic peroxidases (E.C. 1.11.1.7.) of three pear (Pyrus communis L.) cultivars, representing an increasing scale of graft incompatibility with quince (Cydonia oblonga Mill.), and of the quince rootstock EM A, were analyzed by discontinuous non-denaturing polyacrylamide gel electrophoresis. Clear qualitative variations were detected among the electrophoretic patterns of the pear cultivars. These variations were observed at peroxidase isoforms that were slow migrating in the gels and were predominant in the callus extracts instead of the bark extracts. The roles of the electrophoretic methods and of the anionic peroxidase isoforms in the prediction of graft incompatibility are discussed.   < back .