ALPHA-AMYLASE POLYMORPHISM IN PEACH - A GENETIC-STUDY

Alpha-Amylase has been studied by electrophoresis in the peach tree. This enzyme presents 2 isozymes (fig 1); one with a slow migration, Amy(L), the other with a fast migration, Amy(R). The slow migrating isozyme is widespread among temperate cultivars, the fast one is scarce and seems characteristic of subtropical cultivars (table I). A genetic study of this enzymatic system has been undertaken. These isozymes are coded by 2 codominant alleles of the same locus (table II). There is a linkage of approximately 4 centimorgans between the locus of alpha-amylase and that which determines the type of flower (fig 2; table III), the locus of alpha-amylase is independent of that which controls the color of the flesh (table IV). Finally, the loci which determined the type of flower and the color of the flesh are also independent (table V).