DNA-FINGERPRINTING OF EUCALYPTUS-GRANITICOLA - A CRITICALLY ENDANGERED RELICT SPECIES OR A RARE HYBRID

Eucalyptus graniticola is known from a single plant located on a grani te outcrop south-east of Perth in Western Australia. Since its discove r: in 1987, it has been uncertain whether this eucalypt is a relict sp ecies or a hybrid and, consequently, further study is required in orde r to devise appropriate conservation strategies. The similarity of fea tures, such as leaf, bud and fruit morphology, to those of E. rudis, a common tree found in the vicinity, suggested that E. graniticola is a hybrid. This study uses random amplified polymorphic DNA (RAPD) analy sis to demonstrate the additive inheritance of DNA markers from E. rud is and E. drummondii, the putative parent species, in E. graniticola. All the markers detected for E, graniticola using nine primers were sh ared with either E. rudis (40 per cent), E. drummondii (35 per cent) o r both parent species (25 per cent). The DNA fingerprinting results, c ombined with other factors, such as the segregation of cotyledon morph ology, demonstrate the hybrid origin of E. graniticola. As a result, c onservation of this rare eucalypt should rely more on ex situ propagat ion and storage than on active management.