Genetic diversity between three species of Davidsonia - the Australian Native plum

Abstract

Davidson's plum (Davidsonia spp) is an endangered Australian native plum with high commercial potential due to its wide range of product uses. Molecular marker analysis using randomly amplified DNA fingerprinting (RAF), provided a preliminary view of genetic relationships between three species, D. pruriens, D. jerseyana and D. johnsonii. Using five accessions of each species, 47 dominant markers were identified, with only 13% of markers observed in all accessions. Considerable diversity was detected within species (HS=0.126) though differences were well resolved (GST=0.57). The tropical north Queensland species, D. pruriens, was the least diverse. Several markers could be classified as diagnostic of this species, However, the sympatric species D. jerseyana and D. johnsonii, found in subtropical coastal northern New South Wales, were not particularly closely related, and shared only one marker not found in D. pruriens. Genetic diversity was relatively high within these two species. A more comprehensive analysis is underway for all three species with the useful RAF marker system, which will have implications for the selection, improvement, and conservation of these threatened and endangered species.