GENETICS OF SUPEROXIDE-DISMUTASE IN APPLE

Four zones of superoxide dismutase (SOD), activity were detected in ap ple. Genetic studies confirmed the presence of three genes Sod-1, Sod- 3 and Sod-4 with three, two and two alleles respectively, including on e null allele. One of these genes, Sod-1, was found to be loosely link ed to Prx-2 and Prx-3. The Sod-1a allele predominated in all the three groups studied, cultivars, rootstocks and Malus species. The distinct achromatic bands produced by SOD after electrophoresis facilitate its important role with peroxidase (PRX), glutamate oxalacetate transamin ase (GOT) and phosphogluconate dehydrogenase (PGD) in the discriminati on of apple cultivars.