| Titre : |
Molecular evolutionary rates shed new light on the relationships of Festuca, Lolium, Vulpia and related grasses (Loliinae, Pooideae, Poaceae) |
| Type de document : |
texte imprimé |
| Auteurs : |
Pilar Catalán, Auteur ; Pedro Torrecilla, Auteur ; Jose Angel López RodrÃguez, Auteur |
| Importance : |
pp. 45-70 |
| Langues : |
Anglais (eng) |
| Catégories : |
[Espèces (in biblio)] Festuca
[Espèces (in biblio)] Lolium
[Espèces (in biblio)] Vulpia
|
| Mots-clés : |
ITS trnL-F. phylogénie |
| Résumé : |
"Festuca L., Vulpia Gmel. and Latium L. are the three main genera of subtribe Loliinae, a group of temperate grasses characterized by their festucoid-type spikelet. Recent phylogenetic studies based on separate and combined analyses of nuclear ITS and chloroplast trnL-F nucleotide sequences have shown that the large genus Festuca, as traditionally circumscribed, is a paraphyletic assemblage of several Loliinae representatives. Monophyletic Festuca s.l. splits into two main diverging lineages, the 'broad-leaved Festuca' and the 'fine-leaved Festuca', each encompassing different genera and with several morphologically-intermediate taxa placed between them or at the base ofthe 'fine-Ieaved' clade. AH these lineages include both perennial and annual taxa that show significant and paraHel differences in rates of nucleotide substitution for the two genomes analyzed. Comparative rate analysis indicate that the 'fine-Ieaved Festuca' evolve, in general terms, faster than the 'broad-Ieaved Festuca', and have presumably been derived from them. Relative rate ratios support the minimum-generation-time hypothesis in both lineages, implying the existence of stabilized selection processes for the slow evolving perennials and rapid adaptive mechanisms for the rapidly evolving annuals. High divergences in rate heterogeneity may be responsible for unsatisfactory resolution at the basal node of the festucoid ITS tree. These
results, together with conflicts between the ITS and the trnL-F trees in the placement of several taxa suggests that the existence of past reticulation events, might have profound implications on their classification." (source : auteurs) |
| Type de publication : |
article de livre |
| Référence biblio : |
Catalán P., Torrecilla P., López RodrÃguez J., 2006 - Molecular evolutionary rates shed new light on the relationships of Festuca, Lolium, Vulpia and related grasses (Loliinae, Pooideae, Poaceae). In : Bailey J., Ellis G., Eds, 2006 - Current taxonomic research on the British & European Flora (Leicester, 13-14 September 2003). London : Botanical Society of the British Isles, 45-70. |
| ID PMB : |
6458 |
| Permalink : |
http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=6458 |
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Molecular evolutionary rates shed new light on the relationships of Festuca, Lolium, Vulpia and related grasses (Loliinae, Pooideae, Poaceae)