SEGARRA, JOSE GABRIEL* and PILAR CATALAN. Dept. Agricultura, University of Zaragoza, Miguel Servet 177, 50013 Zaragoza (Spain). - Comparative allozyme and RAPD genetic studies on the endemic Borderea chouardii and on its congener B. pyrenaica (Dioscoreaceae) from the Pyrenees (North-eastern Spain).
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