|
Dépouillements
Ajouter le résultat dans votre panierReproductive ecology of the endangered alpine species eryngium alpinum l. (apiaceae) : phenology, gene dispersal and reproductive success / Myriam Gaudeul in Annals of Botany, 93 (2004)
Titre : Reproductive ecology of the endangered alpine species eryngium alpinum l. (apiaceae) : phenology, gene dispersal and reproductive success Type de document : Électronique Auteurs : Myriam Gaudeul (1976-) ; Irène Till-Bottraud Année de publication : 2004 Article en page(s) : 711-721 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Phénologie Mots-clés : Eryngium alpinum L. Résumé : Background and aims Eryngium alpinum (Apiaceae) is an endangered perennial, characteristic of the Alpine flora. Because the breeding system influences both demographic (reproductive success) and genetic (inbreeding depression, evolutionary potential) parameters that are crucial for population maintenance, the reproductive ecology of E. alpinum was investigated. Specifically, the aims of the study were (1) to determine the factors (resources and/or pollen) limiting plant fitness; and (2) to assess the potential for gene flow within a plant, within a patch of plants, and across a whole valley where the species is abundant. Methods Field experiments were performed at two sites in the Fournel valley, France, over three consecutive years. Studies included a phenological survey, observations of pollinators (visitation rates and flight distances), dispersal of a fluorescent powder used as a pollen analogue, the use of seed traps, determination of the pollen/ovule ratio, and an experiment to test whether seed production is limited by pollen and/or by resources. Key resultsE. alpinum is pollinated by generalist pollinators, visitation rates are very high and seed set is resource‐ rather than pollen‐limited. The short flights of honeybees indicate a high potential for geitonogamy, and low pollen and seed dispersals suggest strong genetic structure over short distances. These results are interpreted in the light of previous molecular markers studies, which, in contrast, showed complete outcrossing and high genetic homogeneity. Conclusions. The study highlights the usefulness of adopting several complementary approaches to understanding the dynamic processes at work in natural populations, and the conservation implications for E. alpinum are emphasized. Although the studied populations do not seem threatened in the near future, long‐term monitoring appears necessary to assess the impact of habitat fragmentation. Moreover, this study provides useful baseline data for future investigations in smaller and more isolated populations. Lien pérenne : DOI : 10.1093/aob/mch098 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=140705
in Annals of Botany > 93 (2004) . - 711-721Gaudeul, Myriam (1976-), Till-Bottraud, Irène 2004 Reproductive ecology of the endangered alpine species eryngium alpinum l. (apiaceae) : phenology, gene dispersal and reproductive success. Annals of Botany, 93: 711-721.Documents numériques
Consultable
Article (2004)URL
Titre : Comparative ITS and AFLP analysis of diploid cardamine (brassicaceae) taxa from closely related polyploid complexes Type de document : Imprimé Auteurs : Karol Marhold ; Judita Lihová ; Marián Perny ; Walter Bleeker Année de publication : 2004 Article en page(s) : 507-520 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Phylogénie (liens existant entre espèces apparentées) Mots-clés : Cardamine pratensis L. Cardamine raphanifolia Cardamine amara L. Résumé : Background and aims: Diploid representatives from the related polyploid complexes of Cardamine amara, C. pratensis and C. raphanifolia (Brassicaceae), were studied to elucidate phylogenetic relationships among the complexes and among the individual taxa included. Methods: Two independent molecular data sets were used: nucleotide sequences from the internal transcribed spacers (ITS) of nrDNA, and amplified fragment length polymorphism (AFLP) markers. Seventeen diploid taxa from the studied groups were sampled. Key results: Both ITS and AFLP analyses provided congruent results in inferred relationships, and revealed two main lineages. While the C. amara group, consisting of C. wiedemanniana and four subspecies of C. amara, was resolved as a well-supported monophyletic group, taxa from the C. pratensis and C. tenera groups (the latter representing diploid taxa of the complex of C. raphanifolia) all appeared together in a single clade/cluster with no support for the recognition of either of the groups. Intra-individual polymorphisms and patterns of nucleotide variation in the ITS region in C. uliginosa and C. tenera, together with the distribution of AFLP bands, indicate ancient hybridization and introgression among these Caucasian diploids. Conclusions: The lack of supported hierarchical structure suggests that extensive reticulate evolution between these groups, even at the diploid level, has occurred (although an alternative explanation, namely ancestral polymorphism in ITS data, cannot be completely excluded). Several implications for the investigation of the polyploid complexes of concern are drawn. When tracing origins of polyploid taxa, a much more complex scenario should be expected, taking into account all relatives as potential parents, irrespective of the group in which they are classified.
Lien pérenne : DOI : 10.1093/aob/mch073 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=149111
in Annals of Botany > 93 (2004) . - 507-520Marhold, Karol, Lihová, Judita, Perny, Marián, Bleeker, Walter 2004 Comparative ITS and AFLP analysis of diploid cardamine (brassicaceae) taxa from closely related polyploid complexes. Annals of Botany, 93: 507-520.Documents numériques
Article (2004)URL
