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Auteur Bruno Colas |
Documents disponibles écrits par cet auteur (6)
trié(s) par (Pertinence décroissant(e), Titre croissant(e)) Affiner la rechercheCentaurea corymbosa, a cliff-dwelling species tottering on the brink of extinction : A demographic and genetic study / Bruno Colas in Proceedings of the National Academy of Sciences of the United States of America, vol. 94, n°7 (Année 1997)
Titre : Centaurea corymbosa, a cliff-dwelling species tottering on the brink of extinction : A demographic and genetic study Auteurs : Bruno Colas, Auteur ; Isabelle Olivieri (1957-2016), Auteur ; Miquel Riba, Auteur Année de publication : 1997 Article en page(s) : pp. 3471–3476 Langues : Anglais (eng) Catégories : [Espèces (in biblio)] Centaurea corymbosa
[Thèmes] Conservation
[Thèmes] Plante à forte valeur patrimonialeMots-clés : aire de répartition diversité génétique réintroduction d'espèces Résumé : "Centaurea corymbosa (Asteraceae) is endemic to a small area (≤3 km2), and <500 individuals reproduce in any given year. Nevertheless, enzyme polymorphism was found within and among the six local extant populations, the most distant at 2.3 km. Levels of gene flow among populations and seed and pollen dispersal data indicated very low dispersal capacity. Rarity of long distance dispersal events coupled with traits such as prolonged juvenile period, monocarpy, and self-incompatibility precludes the establishment of new populations and thus the evolution toward colonization ability through increased dispersal rate, polycarpy, or self-compatibility. The species thus appears to be trapped on an evolutionary dead-end toward extinction, even though, from a preliminary introduction experiment, we conclude that several nearby unoccupied sites would be suitable for the species." (source : auteurs) Type de publication : périodique Référence biblio : Colas B., Olivieri I., Riba M., 1997 - Centaurea corymbosa, a cliff-dwelling species tottering on the brink of extinction : A demographic and genetic study. Proceedings of the National Academy of Sciences of the United States of America, 94 (7) : 3471–3476. ID PMB : 72252 DOI : 10.1073/pnas.94.7.3471 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=72252
in Proceedings of the National Academy of Sciences of the United States of America > vol. 94, n°7 (Année 1997) . - pp. 3471–3476[article]Exemplaires(0)
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Titre : Fine-scale genetic structure and gene dispersal in Centaurea corymbosa (Asteraceae), I. Pattern of pollen dispersal Auteurs : Olivier J. Hardy, Auteur ; Santiago C. González-Martínez, Auteur ; Hélène Fréville, Auteur ; G. Boquien, Auteur ; Agnès Mignot, Auteur ; Bruno Colas, Auteur ; Isabelle Olivieri (1957-2016), Auteur Année de publication : 2004 Langues : Anglais (eng) Catégories : [Espèces (in biblio)] Centaurea corymbosa
[Thèmes] Plante à forte valeur patrimoniale
[Thèmes] Pollinisation, pollen, nectarMots-clés : dispersion pollinique Résumé : "Pollen dispersal was characterized within a population of the narrowly endemic perennial herb, Centaurea corymbosa, using exclusion-based and likelihood-based paternity analyses carried out on microsatellite data. Data were used to fit a model of pollen dispersal and to estimate the rates of pollen flow and mutation/genotyping error, by developing a new method. Selfing was rare (1.6%). Pollen dispersed isotropically around each flowering plant following a leptokurtic distribution, with 50% of mating pairs separated by less than 11 m, but 22% by more than 40 m. Estimates of pollen flow lacked precision (0-25%), partially because mutations and/or genotyping errors (0.03-1%) could also explain the occurrence of offspring without a compatible candidate father. However, the pollen pool that fertilized these offspring was little differentiated from the adults of the population whereas strongly differentiated from the other populations, suggesting that pollen flow rate among populations was low. Our results suggest that pollen dispersal is too extended to allow differentiation by local adaptation within a population. However, among populations, gene flow might be low enough for such processes to occur." (source : auteurs) Note de contenu : Cette article montre que la dispersion du pollen de Centaurea corymbosa est principalement locale mais peut atteindre des distances considérables, avec des implications pour la structure génétique et la différenciation des populations. Type de publication : périodique Référence biblio : Hardy O., González-Martínez S., Fréville H., Boquien G., Mignot A., Colas B., Olivieri I., 2004 - Fine-scale genetic structure and gene dispersal in Centaurea corymbosa (Asteraceae), I. Pattern of pollen dispersal. Journal of Evolutionary Biology, 17 (4) : . ID PMB : 72266 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=72266
in Journal of Evolutionary Biology > vol. 17, n°4 (Année 2004)[article]Exemplaires(0)
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Titre : Fine-Scale Genetic Structure and Gene Dispersal in Centaurea corymbosa (Asteraceae), II. Correlated Paternity Within and Among Sibships Auteurs : Olivier J. Hardy, Auteur ; Santiago C. González-Martínez, Auteur ; Bruno Colas, Auteur ; Hélène Fréville, Auteur ; Agnès Mignot, Auteur ; Isabelle Olivieri (1957-2016), Auteur Année de publication : 2004 Article en page(s) : pp. 1601-14 Langues : Anglais (eng) Catégories : [Espèces (in biblio)] Centaurea corymbosa
[Thèmes] ConservationMots-clés : analyse génétique microsatellite dispersion pollinique Résumé : "The fine-scale pattern of correlated paternity was characterized within a population of the narrow-endemic model plant species, Centaurea corymbosa, using microsatellites and natural progeny arrays. We used classical approaches to assess correlated mating within sibships and developed a new method based on pairwise kinship coefficients to assess correlated paternity within and among sibships in a spatio-temporal perspective. We also performed numerical simulations to assess the relative significance of different mechanisms promoting correlated paternity and to compare the statistical properties of different estimators of correlated paternity. Our new approach proved very informative to assess which factors contributed most to correlated paternity and presented good statistical properties. Within progeny arrays, we found that about one-fifth of offspring pairs were full-sibs. This level of correlated mating did not result from correlated pollen dispersal events (i.e., pollen codispersion) but rather from limited mate availability, the latter being due to limited pollen dispersal distances, the heterogeneity of pollen production among plants, phenological heterogeneity and, according to simulations, the self-incompatibility system. We point out the close connection between correlated paternity and the “TwoGener” approach recently developed to infer pollen dispersal and discuss the conditions to be met when applying the latter." (source : auteurs) Note de contenu : Cet article se concentre sur la structure génétique fine et les mécanismes de dispersion des gènes au sein d'une population de Centaurea corymbosa, une espèce de plante endémique à aire de répartition restreinte. L'étude utilise des microsatellites et des analyses de progéniture naturelle pour évaluer la paternité corrélée à la fois au sein des fratries et entre elles, sur différentes échelles spatiales et temporelles. Il vise à comprendre les schémas de dispersion génétique et les modes de reproduction de Centaurea corymbosa afin d'élaborer des stratégies de conservation permettant de maintenir sa diversité génétique et d'assurer sa survie à long terme. Type de publication : périodique Référence biblio : Hardy O., González-Martínez S., Colas B., Fréville H., Mignot A., Olivieri I., 2004 - Fine-Scale Genetic Structure and Gene Dispersal in Centaurea corymbosa (Asteraceae), II. Correlated Paternity Within and Among Sibships. Genetics, 168 (3) : 1601-14. ID PMB : 72265 En ligne : https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1448787/ Format de la ressource électronique : document Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=72265
in Genetics > vol. 168, n°3 (Année 2004) . - pp. 1601-14[article]Titre précédentExemplaires(0)
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Titre : Multilocus genetic structure at contrasted spatial scales of the endangered water fern Marsilea strigosa Willd. (Marsileaceae, Pteridophyta) Auteurs : Renaud Vitalis, Auteur ; Miquel Riba, Auteur ; Bruno Colas, Auteur ; Patrick Grillas, Auteur ; Isabelle Olivieri (1957-2016), Auteur Année de publication : 2002 Article en page(s) : pp. 1142-55 Langues : Anglais (eng) Catégories : [Espèces (in biblio)] Marsilea strigosa
[Thèmes] Conservation
[Thèmes] Plante à forte valeur patrimoniale
[Thèmes] ReproductionMots-clés : diversité Génétique Résumé : "Marsilea strigosa (Marsileaceae, Pterydophyta) is a rare water fern found in the Mediterranean basin, in temporary flooded habitats only. We analyzed the level and the distribution of genetic variation at seven microsatellite loci, both at the Mediterranean scale and at a narrower scale within a highly fragmented French metapopulation. Genetic diversity among individuals within each pond suggests that M. strigosa reproduces predominantly through selfing. The very high population differentiation at the Mediterranean scale indicates that gene flow (if any) is highly restricted. Similar differentiation is also found at the scale of a single metapopulation. The distribution of multilocus genotypes suggests that the genetic variation in this species is maintained mainly through the interplay of mutation and low recombination." (source : auteurs) Type de publication : périodique Référence biblio : Vitalis R., Riba M., Colas B., Grillas P., Olivieri I., 2002 - Multilocus genetic structure at contrasted spatial scales of the endangered water fern Marsilea strigosa Willd. (Marsileaceae, Pteridophyta). American Journal of Botany, 89 (7) : 1142-55. ID PMB : 72259 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=72259
in American Journal of Botany > vol. 89, n°7 (Année 2002) . - pp. 1142-55[article]Exemplaires(0)
Disponibilité aucun exemplaire Role of Corridors in Plant Dispersal : an Example with the Endangered Ranunculus nodiflorus / Florian Kirchner in Conservation Biology, vol. 17, n°2 (Avril 2003)
Titre : Role of Corridors in Plant Dispersal : an Example with the Endangered Ranunculus nodiflorus Type de document : texte imprimé Auteurs : Florian Kirchner, Auteur ; Jean-Baptiste Ferdy, Auteur ; Christophe Andalo, Auteur ; Bruno Colas, Auteur ; Jacques Moret, Auteur Année de publication : 2003 Article en page(s) : pp. 401-410 Langues : Anglais (eng) Résumé : "The proposition that the migration of organisms between habitat patches could be enhanced bycorridors has been much discussed among conservation biologists. But the few experimental studies support-ing the usefulness of corridors have all concerned animal species. We investigated the role of corridors in seeddispersal, studying population genetic and demographic structure in metapopulations of the rare, pond-dwelling, autogamous plant species Ranunculus nodiflorus L. in the Fontainebleau Forest (France). Differenti-ation on three polymorphic isozyme markers was strong among local populations (ponds) within metapopu-lations (sites) and moderate among metapopulations. Partial Mantel tests revealed that the connection ofponds through temporarily flooded natural corridors, facilitating seed migration, had a strong negative effecton genetic differentiation between local populations and that a pond was more likely to be colonized whenconnected by corridors to other occupied ponds. Thus, corridors are probably a key element of landscapestructure for metapopulation dynamics in R. nodiflorus. From a conservation perspective, our results suggestthat corridors could increase the chance of persistence of plant species living in fragmented habitats by pro-moting seed dispersal between habitat patches." Type de publication : périodique Référence biblio : Kirchner F., Ferdy J.-B., Andalo C., Colas B., Moret J., 2003 - Role of Corridors in Plant Dispersal : an Example with the Endangered Ranunculus nodiflorus. Conservation Biology, 17 (2) : 401-410. En ligne : https://botany.natur.cuni.cz/zuzmun/corridors.pdf Format de la ressource électronique : document Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=67231
in Conservation Biology > vol. 17, n°2 (Avril 2003) . - pp. 401-410[article]Exemplaires(0)
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