Low RAPD polymorphism in Archangiopteris itoi, a rare and endemic fern in Taiwan

Archangiopteris itoi, an endemic fern in Taiwan, is under threat due to human disturbance. Based on fossil evidence the origin of Archangiopteris can be dated to the Middle Jurassic Age. Field survey indicated that only eighteen individuals were left in the wild. The population at Lienhwachi, on which the species was named, is now extinct. The genetic variation of the population remaining at Wulai was assessed by RAPD fingerprinting. Of 40 oligo primers, only one revealed polymorphism. Nevertheless, this primer enabled identification of six haplotypes. The low variability within the population is ascribed to the small population size, which was constrained largely due to habitat disturbance. In the small population, genetic drift will have greater effects leading to loss of variation at most loci. In this study, RAPD data indicated that some variation existed within the population, thus suggesting that materials were available for re-establishment of the populations.