Are genetic data relevant in the conservation of species in imminent danger? The case of a critically endangered endemism from the Canary Islands Helianthemum juliae Wildpret (Cistaceae)

Genetic data could be considered irrelevant to the conservation of species in imminent danger, and that habitat protection and ex situ conservation strategies should be carried out regardless of the existence of estimates of genetic diversity. However, genetic data are needed to determine the current state of diversity of the species, the genetic structure and the genetic differentiation between populations and therefore to establish the most suitable management strategy. We compared genetic diversity and differentiation estimated from allozymes and random amplified polymorphic DNA (RAPD) in the three known natural populations of the critically endangered endemism from the Island of Tenerife (Canary Islands) Helianthemum juliae Wildpret. There were discrepancies in levels and structuring of genetic diversity measured with both molecular markers due to genome sampling. So, whereas allozymes allele frequency revealed a low genetic differentiation between natural populations (F-ST = 0.034), the presence/absence of RAPD data matrix showed a considerable level of genetic differentiation (F-ST = 0.397) between these populations. Genetic data identify 20 unique genotypes distributed within H. juliae populations, which supposes an important finding for conservation management of this endangered species. Considering that the three populations showed unique genotypes, management strategies should be focused on strengthening these genotypes in the whole of the species. So, although considerable genetic differentiation has been detected between the natural populations, bearing in mind the high extinction probabilities described for the species, genetic data would support the establishing of new localities with individuals from different natural populations in a conservation genetics strategy.