Conservation genetics of the endangered endemic Sambucus palmensis Link (Sambucaceae) from the Canary Islands

Abstract

Five polymorphic microsatellites (simple sequence repeat; SSR) markers were used to estimate the levels of genetic variation within and among natural populations from different islands of the endangered endemic from the Canary Islands Sambucus palmensis Link (Sambucaceae). Genetic data were used to infer potential evolutionary processes that could have led to present genetic differentiation among islands. The levels of genetic variability of S. palmensis were considerably high; proportion of polymorphic loci (P = 100%), mean number of alleles per locus (A = 6.8), average expected heterozygosity (He = 0.499). In spite of its small population size and endemic character, 58 different multilocus genotypes were detected within the 165 individuals analyzed. All samples located in different islands always presented different multilocus genotypes. Principal Coordinates Analysis, genetic differentiation analysis (F ST and G ST 0 ) and Bayesian Cluster Analysis revealed significant genetic differences among populations located in different islands. However, this genetic differentiation was not recorded among Tenerife and La Gomera populations, possibly revealing the uncontrolled transfer of material between both islands. AMOVA analysis attributed 77% of the variance to differences within populations, whereas 8% was distributed between islands. The levels of genetic differentiation observed among populations, and the genetic diversity distribution within populations in S. palmensis, indicate that management should aim to conserve as many of the small populations as possible. Concentrating conservation efforts only on the few large populations would result in the likelihood of loss of genetic variability for the species.

Effects of clonality on the genetic variability of rare, insular species: the case of Ruta microcarpa from the Canary Islands

“…Support for this interpretation comes from the observation that, contrary to our results in R. microcarpa , low values of genetic diversity were found for sexually reproducing Canarian endangered species ( H e = 0.2 for Anagyris latifolia , González-Pérez et al 2009; H o = 0.113, H e = 0.306 for Lotus kunkelii , Oliva-Tejera et al 2006; H o = 0.100, H e = 0.112 for Cistus chinamadensis ssp. gomerae , Batista et al 2001), while values of genetic diversity were similar to those found in this study for other endangered clonal species such as the Canarian endemic Sambucus palmensis ( H o = 0.550, H e = 0.499; Sosa et al 2010) and the Southern Appalachian endemic Spiraea virginiana ( H o = 0.503, H e = 0.391; Brzyski and Culley 2011). …”

Conservation genetics of Annamocarya sinensis (Dode) Leroy, an endangered endemic species

“…Compared with that in other endangered endemic perennial species [e.g., Berchemiella wilsonii var. pubipetiolata; H E = 0.503 (Kang et al, 2008) and Sambucus palmensis; H E = 0.500 (Sosa et al, 2010)], the genetic diversity detected in A. sinensis was higher.…”

“…Given their small population size and endemic character, we had expected A. sinensis populations to be genetically impoverished (Sosa et al, 2010). To determine whether this rare species exhibits low diversity, a measure or standard for comparison is required.…”

“…Spielman et al (2004) have proposed that most populations of rare species are affected by genetic factors well before stochastic events lead to population extinction. An increasing number of studies have demonstrated the value of genetic data in addressing issues of plant conservation biology, especially for providing conservation recommendations and determining conservation strategies for endangered species (Sosa et al, 2010).…”

Strategies for conservation planning and management of terrestrial ecosystems in small islands (exemplified for the Macaronesian islands)

“…For example, when considering island biodiversity, it is necessary to give particular attention to genetic diversity and to the factors promoting its evolution and differentiation within each taxa, allowing the conservation of micro-niches to preserve the required isolation for the maintenance of that speciation (e.g. Sosa et al, 2010;Schaefer et al, 2011). This question is critical when analysing continuity and heterogeneity at the island level, determining that, as important as the preservation of a viable population, it is critical to ensure, simultaneously, its intrinsic micro-diversity and the resulting ability to respond biologically and physically to disturbances.…”