Use of RAPD analysis in devising conservation strategies for the rare and endangered Grevillea scapigera (Proteaceae)

Extensive human impact in south western Australia has resulted in a high incidence of rarity throughout the highly endemic flora of the region. Grevillea scapigera (Proteaceae) is a typical example, with 27 plants (represented by four extant populations) remaining in the wild. In order to devise an appropriate strategy for the conservation of this species, its population genetics were studied using RAPD analysis, which enabled the discrimination of individual plants and the detection of a relatively high amount of variability (V = 0.32) within G. scapigera. This variability was found to be evenly distributed within the plants analysed despite the clear distinction between most populations (87% of the variability being attributable to single plant difference and 13% to population difference). Finally, RAPD analysis was used to select a small group of plants that captured maximum genetic variability to be used in the recovery program of the species. Because of the low genetic difference between populations, the mixing of these selected plants during the recovery process should not create genetic imbalances. The methods used in this study provide a useful model for future projects involving the recovery of rare flora.