Abstract: Peroxidase isozyme zymograms of the cortex of the shoot of 1 or 2-year old seedling were obtained by starch gel electrophoresis. In different species, cultivars, and root stocks, the ninth enzyme band (A9 is positively correlated with spurtype and dwarfing propensity of rootstock. The A9 is not influenced by seedling age, calture condition, rootstock and interstock. Therefore, it Could be used as a marker for preselection of apple seedling for spurtype and dwarfing of rootstock. The accuracy of this method is about 86%.

Key words: Apple dwarf type, Peroxidase isozyme