Genetic diversity and phylogenetic relationships in plum germplasm resources revealed by RAPD markers

One hundred-and-eight accessions of plum and apricot, including seven plum species (Prunus salicina. P. simonii, P. ussuriensis, P. domestica, P cerasifera, P nigra and P spinosa), seven accessions of wild European plum from Xinjiang, two related species (P armeniaca and P tomentosa) and eight hybrids between plum and apricot were examined using random amplified polymorphic DNA (RAPD) markers. Cluster analysis using the unweighted paired group method of arithmetic means (UPGMA) showed four main clusters: a group comprising apricot (P. armeniaca) and hybrids between apricot and plum; a Chinese plum-type group; a European plum group (P domestica); and an outgroup including P ussuriensis, P cerasifera, P. nigra, P. spinosa and P. tomentosa. Data also revealed that P simonii should be a variant of P salicina, and P ussuriensis is an independent species. P cerasifera and P spinosa were distinct from the European plum group, disproving the hypothesis that P domestica originated from natural hybrids of P cerasifera and R spinosa.