Population genetics and conservation of the extremely narrow Pyrenean palaeoendemic Glandora oleifolia (Boraginaceae)

Background: Glandora oleifolia is one of the most narrowly restricted endemics of the Iberian Peninsula. It occurs in two locations, separated by 5 km in the south-eastern Pyrenees. The species is listed as 'vulnerable' in the Spanish Red List, and it is legally protected in Catalonia. Aims: To study the genetic diversity and population structure, and to review the conservation status and the threats to the survival of this species. Methods: The genetic variation of the two extant subpopulations was surveyed by means of allozymes and random amplification of polymorphic DNA (RAPD). Results: Both markers indicated depleted levels of genetic variability for G. oleifolia, in agreement with the expectation for endemic species, and low genetic divergence among the two subpopulations (below 10% with the two nuclear markers). Conclusions: The evolutionary history of this palaeoendemic species - repeated population bottlenecks and/or local extinction of populations during the glacial periods of the Quaternary - could have enhanced the loss of its genetic diversity.