USE OF RAPD MARKERS TO DOCUMENT THE ORIGIN OF THE INTERGENERIC HYBRID MARGYRACAENA-SKOTTSBERGII (ROSACEAE) ON THE JUAN FERNANDEZ ISLANDS

Bands of random amplified polymorphic DNA (RAPDs) were used as markers to test the hypothesis that the species x Margyracaena skottsbergii, which is endemic to the island of Masatierra in the Juan Fernandez archipelago, represents an intergeneric hybrid between Acaena argentea and Margyricarpus digynus. Thirteen 10-mer primers produced 18 consistent species-specific bands for A. argentea and 27 for M. digynus, with all 45 bands present in the presumed hybrid x Margyracaena. A second species of Acaena on Masatierra, A. ovalifolia, has 23 unique amplified bands in all plants examined, and it shares none of these bands with x Margyracaena. The data from RAPDs are concordant with morphology in implicating Acaena argentea rather than A. ovalifolia as one parent of x Margyracaena. RAPDs can provide numerous genetic markers while requiring minimal quantities of DNA, thereby making them attractive for the study of hybridization, particularly in rare plants where DNA amounts may be limiting.