Comparative genetic studies on the two taxa of the Pyrenaean relict genus Borderea (Dioscoreaceae) have been conducted using allozyme and RAPD markers. Sampling included individuals from the only known population of the critically endangered B. chouardii and from 6 populations within the distribution range of its congener B. pyrenaica. Both codominant and dominant alleles have provided markers that genetically separate these two species. Whereas allozymes have failed to detect significant levels of genetic diversity within and among populations, the RAPD alleles have shown to be useful to discern the genetic structure of those populations. Fixed heterozygous patterns found for two allozyme loci might indicate a shared gene duplication event, a hybrid origin of this genus or a different selection rate depending on the genotype.

Key words: Allozymes, Borderea, Dioscoreaceae, Pyrenees, RAPD