A comparison of the genetic diversity of the common endemic Hawaiian plant, Clermontia kakeana Meyen, and an endangered species, Cyanea mceldowneyi Rock (Campanulaceae: Lobelioideae)

Oceanic island archipelagoes provide opportune settings to study questions of evolutionary interest. I have used two species of Hawaiian Lobelioideae, Clermontia kakeana and Cyanea mceldowneyi, as a model to compare the population biology of a common versus a rare plant species. Clermontia kakeana is relatively common and occurs on three islands, Oahu, Maui and Molokai. Cyanea mceldowneyi is an endangered species sympatric with Clermontia kakeana in the Waikamoi Stream drainage of East Maui at elevations between 850 and 1250 meters. Populations of both species were located and censuses taken. Life history traits were observed. Vouchers and samples for molecular analyses were collected from each population.; Randomly Amplified Polymorphic DNAs (RAPDs) were employed to assess the genetic diversity of the two species. Within population and between population identities were determined for both Clermontia kakeana and Cyanea mceldowneyi. A phylogenetic tree was constructed from the RAPDs data using PAUP, PHYLIP, and the RAPDistance program available from the Australian National University.; Results from the within and between population identity matricies for Clermontia kakeana show that populations between islands possess a lower identity index than those populations on the same island. There is no difference in identity indicies when comparing population within the same island and individuals within a single population. A phylogenetic tree produced from the RAPDs data suggest an Oahu origin for Clermontia kakeana, with subsequent dispersal to Maui and Molokai.; A direct comparison of the overall genetic diversity of both species shows that the endangered Cyanea mceldowneyi has greater overall diversity than the more common and widespread Clermontia kakeana. This may be attributable to the exclusively clonal propagation of Cyanea mceldowneyi, such that this form of reproduction maintains the diversity found in a previously outbreeding species. Further investigations with related species are planned to test this hypothesis.