Rodriguez A.M.,Jardin Botanico Canario Viera y Clavijo |
Scholz S.,University of La Laguna
Willdenowia | Year: 2013
A new species of Trisetum Pers. (Poaceae, Aveneae), T. tamonanteae Marrero Rodr. & S. Scholz, from Fuerteventura, Canary Islands, Spain, is described. We discuss its affinities to related taxa, and provide information about its habitat and ecology, noting its possible ability to reproduce vegetatively by pseudoviviparism, as well as the conservation status of its populations. This is the first reference to Trisetum s. str. for the Canary Islands and the whole of Macaronesia. © 2013 BGBM Berlin-Dahlem.
Caujape-Castells J.,Jardin Botanico Canario Viera y Clavijo
Conservation Genetics | Year: 2010
While knowledge of the degree of inter-population genetic differentiation underlies the understanding of microevolutionary processes in any organism, its calculation through GST, FST, or θ (which, unlike the previous two, was designed to correct for unequal and small sample sizes) is often based in severely restricted intra-population samples, which are nonetheless tacitly assumed adequate to their accurate estimation. Empirical assessment of the influence of the number and intra-population distribution of samples on the values of GST and θ for several Canarian endemic plants compellingly suggests that (1) contrary to expectations based on simulated datasets, θ does not account for empirical sampling bias better than GST; (2) sample sizes being equal, collections scattered across each population's occupancy area entail significantly lower over-estimates of GST and θ than if they only consider one of the population extremes, especially in narrow allogamous taxa with small populations; (3) in small samples, a scattered sampling strategy is significantly less sensitive to GST inflation than sampling in one of the population extremes; and (4) a software-related component of bias should be considered when pooling values of GST from different studies to calculate averages. Thus, unlike the sampling methods used for many plant endemics from the Canaries and other regions, collections for a reliable estimation of inter-population differentiation using molecular markers should encompass the whole occupancy area of each population, and include a higher proportion of individuals respect to the total size in narrow endemics than in widespread congeners. Critically, the high average allozyme inter-population differentiation reported for the Canarian endemic Flora is possibly an over-estimate, and could be explained predominantly by the generally biased intra-population sampling associated with GST estimates, rather than by specific factors of insularity that restrict gene flow radically, as it has been hitherto assumed. © 2009 Springer Science+Business Media B.V.
Desamore A.,University of Liege |
Laenen B.,University of Liege |
Gonzalez-Mancebo J.M.,University of La Laguna |
Jaen Molina R.,Jardin Botanico Canario Viera y Clavijo |
And 4 more authors.
Journal of Biogeography | Year: 2012
Aim Using the heather Erica scoparia s.l. as a model, this paper aims to test theoretical predictions that island populations are genetically less diverse than continental ones and to determine the extent to which island and continental populations are connected by pollen- and seed-mediated gene flow. Location Macaronesia, Mediterranean, Atlantic fringe of Europe. Methods Patterns of genetic diversity are described based on variation at two chloroplast DNA (cpDNA) loci and one nuclear DNA (nDNA) locus for 109 accessions across the entire distribution range of the species. Global patterns of genetic differentiation were investigated using principal coordinates analysis. Genetic differentiation between island and continental areas, estimations of pollen- and seed-mediated gene flow, and the presence of phylogeographical signal were assessed by means of F st/N ST (continental scale) and F ij/N ij (local scale). Extant and past distribution ranges of the species were inferred from niche modelling using layers describing present and Last Glacial Maximum (LGM) macroclimatic conditions. Results The Azores exhibited a significantly higher genetic diversity than the continent. The lowest levels of genetic differentiation were observed between the Azores and the western Mediterranean, and the diversity observed in the Azores resulted from at least two colonization waves. Within the Azores, kinship coefficients showed a significant and much steeper decrease with geographical distance in the cpDNA than in the nDNA. The distribution predicted by LGM models was markedly different from the current potential distribution, particularly in western Europe, where no suitable areas were predicted by LGM models, and along the Atlantic coast of the African continent, where LGM models predicted highly suitable climatic conditions. Main conclusions The higher diversity observed in Azorean than in continental populations is inconsistent with MacArthur and Wilson's equilibrium model and derived theoretical population genetic expectations. This inverted pattern may be the result of extinction on the continent coupled with multiple island colonization events and subsequent allopatric diversification and lineage hybridization in the Azores. The results highlight the role of allopatric diversification in explaining diversification on islands and suggest that this process has played a much more significant role in shaping Azorean biodiversity than previously thought. © 2011 Blackwell Publishing Ltd.
Torras-Claveria L.,University of Barcelona |
Berkov S.,University of Barcelona |
Jauregui O.,University of Barcelona |
Caujape J.,Jardin Botanico Canario Viera y Clavijo |
And 3 more authors.
Phytochemical Analysis | Year: 2010
Introduction - Pancratium canariense Ker Gawler is a plant species belonging to family Amaryllidaceae. Plants from this family are known to synthesise a particular type of bioactive compounds, named Amaryllidaceae alkaloids, which have shown AChE inhibitory activity. Objective - To perform the metabolite profiling of methanolic extracts from P. canariense in order to identify bioactive compounds. Methodology - Methanolic extracts from bulbs, leaves and fruits were separated into alkaloid-free apolar and polar fractions, as well as alkaloid fractions, and subjected to AChE assay. Metabolite profiling of extracts and fractions of P. canariense was carried out by GC-EI-MS and LC-ESI-TOF-MS. Results - AChE inhibitory activities of the alkaloid fractions at a concentration of 10 μg/mL were 29.80 ± 0.91, 40.93 ± 4.60 and 58.06 ± 1.18% for the bulbs, leaves and fruits, respectively. Seventy-six metabolites-mono-, di- and trisaccharides, fatty acids, amino acids, sterols as well as several Amaryllidaceae alkaloids-were detected. Further purification of the alkaloids from the methanolic extracts resulted in the detection of 31 compounds including several potent AChE inhibitors such as habranthine and galanthamine, and the structural elucidation of 3-O-acetylhabranthine, a new natural compound with potential AChE inhibitory activity. Conclusion - The described method resulted in effective integration of both GC-EI-MS and LC-ESI-TOF-MS strategies, which permitted the identification of many metabolites, as well as the structural elucidation of new compounds with potential AChE inhibitory activity. Copyright © 2009 John Wiley & Sons, Ltd.
Ojeda I.,University of British Columbia |
Caujape-Castells J.,Jardin Botanico Canario Viera y Clavijo |
Jaen-Molina R.,Jardin Botanico Canario Viera y Clavijo |
Marrero A.,Jardin Botanico Canario Viera y Clavijo |
Cronk Q.C.B.,University of British Columbia
International Journal of Plant Sciences | Year: 2012
Bird pollination has evolved in four species of Macaronesian Lotus from a bee-pollinated ancestor. The transition is associated with the modification of several floral traits, including flower color and size, relative size and orientation of the petals, and nectar composition and quantity. Here, we examine petal surface micromorphology in relation to pollination type, using SEM and LM. In the bee-pollinated Lotus (the majority of the genus), papillose conical cells (PCS) are the most abundant epidermal type on dorsal and lateral petals. However, bird-pollinated species completely lack PCS on their dorsal petals and have only a small patch of PCS in a highly localized region of the lateral petal. In the bee-pollinated species (including those most closely related to the bird-pollinated species), PCS develop early in floral development. In contrast, the small amount of residual PCS in bird-pollinated species forms later in development, after the other two major epidermal types have been formed. The almost complete elimination of PCS during the shift of pollination syndrome from bee to birds may be adaptively driven as a both probird and antibee trait. © 2012 by The University of Chicago.