Isoelectric focusing of grapevine peroxidases as a tool for ampelography

Enzymatically active proteins have been isolated from the phloem of internodes of 71 Vitis species and cultivars and separated by thin layer electrofocusing. Peroxidases (EC 1.11.1.7.) yielded a pattern which could be differentiated into up to 8 bands within the pH range 6 through 11. The patterns obtained from different samples were congruent with ampelographic data, they are virtually identical within the families of Pinot and Silvaner, as weil as between haploid and diploid forms of one variety, even under different environmental conditions. American and Asian wild species and some interspecific hybrids show a slight shift of the isoelectric point of one enzyme band as compared to Vitis vinifera varieties