GENETIC DIVERSITY IN BANKSIA AND DRYANDRA (PROTEACEAE) WITH EMPHASIS ON BANKSIA-CUNEATA, A RARE AND ENDANGERED SPECIES

Random amplified polymorphic DNA (RAPD) markers were investigated as a tool for estimating genetic diversity within 33 species of Banksia an d three species of Dryandra. Three primers were used on DNA from 10 se eds per species, and band data were pooled to give between 52 and 89 b ands per species, most of which were polymorphic. Genetic diversity wa s calculated using sh published metrics on three species, for which al lozyme data were also available. Based on between-method consistency, three metrics were chosen for analysis of the full data set. Levels of genetic diversity in Banksia and Dryandra ranged from 0.59 to 0.90. B ased on this information, a detailed study was conducted on all 10 kno wn populations of B. cuneata, a rare and endangered species, with a re stricted geographical distribution in south-western Australia. Estimat es of genetic diversity ranged from 0.65 to 0.74, which is high for a rare and endangered species. Analysis of molecular variance (AMOVA) wa s used to partition RAPD variation within and between populations. Nea rly all of the variation was attributable to individuals within popula tions, indicating a lack of population divergence. It is suggested tha t the combination of bird pollination and high outcrossing rates in B. cuneata maintain genetic diversity and cohesion between the populatio ns.