Peroxidase isoenzyme patterns in Vitaceae

The isolation of active cytoplasmatic enzymes has been simplified and improved. Employing this technique 313 different cultivars and species of Vitis have been analyzed for peroxidase isoenzymes in the phloem of dormant canes. Using isoelectric focusing on polyacrylamid gel layers 38 different banding patterns were obtained. Bands with isoelectric points pH 3.5 to 3.8 (type A) were found to be characteristic for Vitis vinifera cultivars (211 samples). The frequency of type A in other Vitis species is 5%. Only half of the interspecific cvs tested showed a type A pattern. Variability in neutral to basic peroxidases was useful to group V. vinifera and interspecific cultivars. The ploidy had no influence on the patterns whereas different colour variants exhibited differences. The single polymorphic isoenzyme peroxidase is sufficient to group cultivars and to discriminate between two samples