Random amplified polymorphic DNA (RAPD) analysis of genotypic identities in Eucalyptus clones

Vegetative micropropagation is usually applied in Eucalyptus in order to obtain clones for improvement on plant propagation for commercial purposes. One problem of this technique is somaclonal variation, which serves as a source of undesirable genetic variation, in a propagation of previously selected clones. To analyze the genotypes, Eucalyptus clones hybrids obtained by vegetative micropropagation were evaluated by RAPD markers. Fifteen arbitrary 10-mer primers were successfully used to amplify DNA of four clones obtained in different subcultures from callus to adult plants. During the analysis of clone "A" polymorphism was observed in the pattern of fragments of amplified DNA among subcultures, producing 39 polymorphic and 23 monomorphic bands. The genetic distance varied from 0 to 37% within this clone. For clones "B", "C" and "D" no polymorphism was observed in all plants in different ages. These results suggest the existence of sample exchange or somaclonal variation in clone "A" and showed that RAPD markers are an efficient tool for the early analysis of genotypes in Eucalyptus clones.