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

Vegetative micropropagation is usually applied in Eucalyptus in order to ob tain clones for improvement on plant propagation for commercial purposes. O ne problem of this technique is somaclonal variation, which serves as a sou rce of undesirable genetic variation, in a propagation of previously select ed clones. To analyze the genotypes, Eucalyptus clones hybrids obtained by vegetative micropropagation were evaluated by RAPD markers. Fifteen arbitra ry 10-mer primers were successfully used to amplify DNA of four clones obta ined in different subcultures from callus to adult plants. During the analy sis of clone "A" polymorphism was observed in the pattern of fragments of a mplified DNA among subcultures, producing 39 polymorphic and 23 monomorphic bands. The genetic distance varied from 0 to 37% within this clone. For cl ones "B", "C" and "D" no polymorphism was observed in all plants in differe nt ages. These results suggest the existence of sample exchange or somaclon al variation in clone "A" and showed that RAPD markers are an efficient too l for the early analysis of genotypes in Eucalyptus clones.