Phylogeography and conservation perspectives of an endangered macaronesian endemic: Picconia azorica (Tutin) Knobl. (Oleaceae)

Abstract

AB The Azores provide an excellent field test for research activities aimed\ud at developing conservation strategies for endangered tree species. In\ud this work, the urgency to promote Picconia azorica conservation programs\ud addressed (a) insights into the biotaxonomy of the species (including an\ud evaluation of its origin and relationships with the only congeneric\ud species of P. azorica: P. excelsa from the Canary and Madeira islands)\ud and (b) the evaluation of P. azorica genetic diversity. Plastid DNA\ud sequence analysis and molecular markers (RFLP and SSR) were used for\ud this purpose. Phylogenetic data suggest the monophyly of Picconia and\ud support a late Miocene divergence of the two species. Three polymorphic\ud cpSSR loci allowed the identification of five different haplotypes in P.\ud azorica. Uniqueness and relictuality of lineages are presented and\ud discussed. Picconia azorica intra-specific diversity patterns revealed\ud low genetic diversity and a weak genetic structure, which could result\ud from long-lasting ecological stability and efficient inter-island seed\ud movement that have been severely affected in recent times. The species\ud survival is at risk, and we suggest management practices focusing on ex\ud situ and in situ conservation units based on eco-genetic data.\ud Additional measures contributing to mild erosion of the genepool and to\ud remove barriers to seed dispersal are indicated

Genetic Variability and Differentiation Among Populations of the Azorean Endemic Gymnosperm Juniperus brevifolia: Baseline Information for a Conservation and Restoration Perspective

“…A low amount of geographical structure between islands was also found in population genetic studies of Picconia azorica (Tutin) Knobl. (Oleaceae), another tree endemic to the Azores (Ferreira et al 2010). Our results for J. brevifolia (55-58%) were not as extreme as those found for J. phoenicea (77%, Meloni et al 2006).…”

Morphological and molecular data from Madeira support the persistence of an ancient lineage ofTaxus baccataL. in Macaronesia and call for immediate conservation actions

“…For ancient plant lineages, and conifers in particular, variation of molecular markers may reflect imprints of extremely ancient demographic events dating back to several millions of years (González-Martí-nez et al 2010). In this scenario, inspections into diversity patterns of Macaronesian gymnosperms are likely to detect important sources of variation, which may in turn enhance the evolutionary models of this flora, and stimulate new research issues and conservation programs (Ferreira et al 2011).…”

“…This hypothesis would be satisfactory for Taxus baccata, as it is a wellknown endozoochorous species. Endozoochory played a crucial role in successful dispersal to Macaronesian archipelagos since their formation in the Tertiary, as demonstrated by the establishment of ancient lineages of fleshy-fruited trees that occur in laurisilva (genera Arbutus, Hedera, Ilex), and mesic habitats (Juniperus, Olea, Picconia) (Vargas 2007;Ferreira et al 2011). Such Tertiary vegetation would have established under a favourable climatic regime during the Miocene, until its continental erosion in the Pleistocene climatic change.…”

Development, Structure, and Function of Torus–Margo Pits in Conifers, Ginkgo and Dicots

“…Both species grow in Macaronesia, P. excelsa is on the Canary Islands and Madeira, and P. azorica in the Azores (Humphries 1979;Gomes 1998;Arteaga et al 2006;Ferreira et al 2011). Picconia is considered "a xerophytic, evergreen tree genus" (Ferreira et al 2011). A recent molecular study has clearly confirmed Picconia's two species as distinct (Ferreira et al 2011).…”

“…It should come as no surprise then to learn that the two species of Picconia (P. azorica and P. excelsa) have torus-bearing intervascular pit membranes (Dute et al 2008;Rabaey et al 2008a). Both species grow in Macaronesia, P. excelsa is on the Canary Islands and Madeira, and P. azorica in the Azores (Humphries 1979;Gomes 1998;Arteaga et al 2006;Ferreira et al 2011). Picconia is considered "a xerophytic, evergreen tree genus" (Ferreira et al 2011).…”