Phylogeography and conservation of three oil mallee taxa, Eucalyptus kochii ssp kochii, ssp plenissima and E-horistes

Eucalyptus kochii ssp. kochii, ssp. plenissima and E. horistes are planted for eucalypt oil production and land rehabilitation in Western Australia. V ariation in cpDNA was investigated by RFLP analysis of 10 populations acros s the distribution of the three taxa. Diversity in the chloroplast genome w as high, with most of the diversity distributed between populations. The th ree taxa formed a cohesive group that was clearly differentiated from E. ol eosa, which was used as an outgroup. There was some differentiation of E. k ochii ssp. kochii from E. kochii ssp. plenissima and E. horistes. Several m utations specific to the E. kochii ssp. kochii, ssp. plenissima and E. hori stes haplotypes were present in a variant of E. oleosa, suggesting that int rogression has occurred. Congruence between cp gene genealogy and geographi c distribution was consistent with limited maternal gene flow between popul ations. There was little structuring of haplotype diversity and the pattern of variation in the cp genome was congruent with that previously detected in the nuclear genome.