Abstract

Amplification profiles produced by polymerase chain reaction (PCR) using randomly amplified polymorphic DNA sequences (RAPD) have the potential for species and cultivar identification. Since most rhododendron plants are vegetatively propagated, it is imperative that RAPD profiles be stable during this propagation. Three species of rhododendron, Rhododendron arborescens, R. atlanticum and R. yedoense var. poukhanense were used to produce species specific amplification profiles. Stability of amplification profiles among individually cloned plants of each species were studied. Ten plants of R. atlanticum, 9 of R. arborescens, and 10 of R. yedoense var. poukhanense were studied with 10 random primers. No polymorphism was observed among individual plants of R. atlanticum and R. arborescens with all the primers. The amplification product of one plant of R. yedoense var. poukhanense showed a difference of one band with one primer. The rest of the profiles with 9 primers were identical in all plants of this species. In order to ascertain that RAPD markers can indeed reveal real genetic differences among plants, F2 plants of two hybrids were analyzed. In contrast to the clonally propagated plants, extensive polymorphisms were observed among the individual F2 plants. Thus, RAPD analysis can be used to detect genetic variability. This stability of RAPD profiles in clonally propagated rhododendron indicates the usefulness of these markers in plant identification.