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Murviel-lès-Montpellier, France

Dias E.F.,University of The Azores | Sardos J.,Bioversity France | Silva L.,University of The Azores | Maciel M.G.B.,University of The Azores | Moura M.,University of The Azores
Plant Systematics and Evolution

The genus Leontodon L. (Asteraceae) comprises approximately 50 species with a natural distribution area covering North America, Europe, northern Africa, and western Asia. Two of these species are endemic to the Azores Archipelago: Leontodon filii and Leontodon rigens. Although both species were targeted with several taxonomic revisions, so far no studies into their genetic diversity have been carried out. In this research, the population genetic structure and diversity of both taxa were assessed using five newly developed SSR markers. Four hundred and thirty-seven individuals collected throughout the archipelago were included in the study. A total of 98 alleles (25-12 per locus, average = 19.6) and an overall excess of homozygotes (multilocus F is = 0.37, range 0.16-0.53) were found for L. rigens populations. For L. filii, 52 alleles in total (8-13 per locus, average = 10.4) were found, overall near the HW equilibrium (multilocus F is = 0.07, range -0.25 to 0.57). The two species showed an equivalent proportion of rare alleles (L. rigens 80.6 %; L. filii 76.9 %). Both a Principal Coordinate Analysis and a Bayesian analysis proposed the existence of two well-defined groups, but pooled L. filii populations from Faial Island with L. rigens populations. The largest proportion of genetic variability was found within populations (L. rigens 72.6%; L. filii 78.9 %). The highest values of gene flow were obtained for L. filii within the central group of islands. Our results update the current distribution given for the Azorean Leontodon taxa, clearly indicating that conservation measures should be applied to several populations. The results also reveal that a revision of the Azorean Leontodon should be carried out to clarify species delimitation. © 2013 Springer-Verlag Wien. Source

Silva L.B.,University of The Azores | Sardos J.,Bioversity France | de Sequeira M.M.,University of Madeira | Silva L.,University of The Azores | And 2 more authors.
Plant Systematics and Evolution

The recently evolved genus Tolpis Adans. has its major center of diversity located in Macaronesia. Although recent advances have been made to understand the relationships of Tolpis species within Macaronesia, little is still known about the genetic patterns and genetic diversity of the Azorean and Madeiran Tolpis populations. To achieve this, a set of 8 microsatellite loci (SSR) was applied to 478 individuals of Tolpis azorica and T. succulenta. Genetic structure analysis, in addition to a spatial analysis, confirmed the existence of geographically circumscribed genetic patterns allied to a barrier effect by the sea in the Azorean T. azorica and T. succulenta. A detailed analysis of T. azorica revealed three different genetic groups, each group being particular to a different Azorean sub-archipelago, while the analysis conducted with T. succulenta confirmed the occurrence of a differential grouping between individuals from Azores and Madeira populations. The impact of catastrophic volcanic events and intense humanization of the habitats is discussed, in view of the present genetic diversity and structure of the species. In general, T. azorica populations showed high Fis values and some populations of T. succulenta both in Azores and in Madeira also showed signs of putative inbreeding. Conservation actions such as the eradication of invasive plant and animal species are advised but translocations of plants or diaspores between islands or between populations of a same island should not be attempted. © 2015 Springer-Verlag Wien Source

Martins J.M.,University of The Azores | Moreira O.C.B.,University of The Azores | Sardos J.,Bioversity France | Maciel M.G.B.,University of The Azores | And 2 more authors.
Biochemical Systematics and Ecology

Picconia azorica (Tutin) Knobl. (Oleaceae) is an endangered species, endemic to the Azores. Samples from 31 populations in 8 islands were genotyped using 8 newly developed nuclear microsatellite markers. From the amplified loci, 81% were polymorphic across all populations and the species showed a relatively high total genetic diversity (HT=0.7). Several populations were close to Hardy-Weinberg equilibrium while others presented positive FIS values (0.02-0.2). The largest proportion of genetic variation (98%) occurred within populations and the level of differentiation between populations, was generally low, although 27% of the population pairwise comparisons showed relatively high differentiation values (0.25≤RST≤0.65). Relatively high levels of gene flow were also found among most populations. Using the Bayesian clustering method implemented in STRUCTURE we found a particular genetic pattern in Corvo samples, and also similarities between Santa Maria, São Miguel and Flores populations. Considerable levels of genetic admixture within P. azorica populations might have resulted from: (i) fruit dispersal by native birds; and/or (ii) human mediated dispersal between islands. Our results revealed the existence of some genetically depauperate populations needing specific conservation measures, and indicate that arbitrary translocation of individuals between islands should be avoided. © 2013 Elsevier Ltd. Source

Silva L.,University of The Azores | Dias E.F.,University of The Azores | Sardos J.,Bioversity France | Azevedo E.B.,University of The Azores | And 2 more authors.

Research dedicated to rare endemic plants is usually focused on one given aspect. However, holistic studies, addressing several key issues, might be more useful, supporting management programmes while unravelling basic knowledge about ecological and population-level processes. A more comprehensive approach to research is proposed, encompassing: phylogenetics/systematics, pollination biology and seed dispersal, propagation, population genetics, species distribution models (SDMs), threats and monitoring.We present a holistic study dedicated to Veronica dabneyi Hochst. ex Seub., an endangered chamaephyte endemic to the Azores. Veronica dabneyi was mainly found associated with other endemic taxa; however, invasive plants were also present and together with introduced cattle, goats and rabbits are a major threat. Most populations grow at somewhat rocky and steep locations that appeared to work as refuges. Seed set in the wild was generally high and recruitment of young plants from seed seemed to be frequent. In the laboratory, it was possible to germinate and fully develop V. dabneyi seedlings, which were planted at their site of origin. No dormancy was detected and time for 50 % germination was affected by incubation temperature. Eight new microsatellite markers were applied to 72 individuals from 7 sites. A considerable degree of admixture was found between samples from the two islands Flores and Corvo, with 98 % of the genetic variability allocated within populations. Levels of heterozygosity were high and no evidence of inbreeding was found. Species distribution models based on climatic and topographic variables allowed the estimation of the potential distribution of V. dabneyi on Flores and Corvo using ecological niche factor analysis and Maxent. The inclusion of land-use variables only slightly increased the information explained by the models. Projection of the expected habitat in Faial largely coincided with the only historic record of V. dabneyi on that island. This research could be the basis for the design of a recovery plan, showing the pertinence of more holistic research approaches to plant conservation. © The Authors 2015. Source

Moreira O.C.B.,University of The Azores | Martins J.M.,University of The Azores | Sardos J.,Bioversity France | Maciel M.G.B.,University of The Azores | And 2 more authors.
Plant Systematics and Evolution

Prunus azorica is an endangered tree endemic to the Azores Archipelago, considered as a top priority species for conservation. Although propagation measures have been studied in detail, and a broad phylogeographic study on P. lusitanica was recently published, a detailed population genetics study devoted to Azorean taxon was lacking. To determine extant patterns of population genetic structure in P. azorica, we analysed eight populations from the five Azorean islands where the species presently occurs and the only extant individual from Flores Island. We also included samples of P. lusitanica subsp. hixa from the Canary Islands and Madeira, and of P. lusitanica subsp. lusitanica from mainland Portugal. Genotyping was undertaken for eight nuclear microsatellite polymorphic loci specifically isolated for P. azorica. Accessions of the different geographic regions were used to sequence ITS and trnL DNA regions. Regarding SSRs, the number of alleles ranged from 5 to 37 (mean = 12.6) per locus and from 2 to 64 per population (mean = 24). Our analysis showed a clear separation between samples from the Azores and those from other regions. Overall, São Miguel populations seemed to encompass the majority of the variability found within the archipelago. Regarding the Azorean populations only, the highest percentage of genetic variation was found within populations (92 %). Still, about 7 % of the variation was found among populations within islands. Expected heterozygosity ranged from values near 0 in the most depauperate populations up to 0.18. With a few exceptions, the level of differentiation between Azorean populations was generally low and gene flow was clearly above 1. Analysis of ITS sequences also detected differences between the Azores and the remaining regions but the trnL region did not reveal any variation. The genetic identity of P. azorica was recognised and thus should be preserved; however, the present results suggest that the Azorean taxon should be reinstated at the subspecies level. © 2013 Springer-Verlag Wien. Source

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