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3 résultat(s) recherche sur le mot-clé 'Cichorieae' 
trié(s) par (Pertinence décroissant(e), Titre croissant(e)) Affiner la recherche Générer le flux rss de la rechercheImpact of interspecific hybridization within a polyploid agamic complex of Pilosella (Asteraceae, Cichorieae) in Bulgaria compared with Central Europe / Anna Krahulcová in Willdenowia, vol. 48, n°3 (Année 2018)
Titre : Impact of interspecific hybridization within a polyploid agamic complex of Pilosella (Asteraceae, Cichorieae) in Bulgaria compared with Central Europe Type de document : Livre Auteurs : Anna Krahulcová, Auteur ; Frantisek Krahulec, Auteur ; Vladimir Vladimirov, Auteur Année de publication : 2018 Article en page(s) : pp. 345-362 Langues : Anglais Catégories : [Espèces (in biblio)] Hieracium
[Espèces (in biblio)] Pilosella
[ZG] Europe centrale
[Thèmes] ApomixieMots-clés : Cichorieae hybridation microévolution ploïdie reproduction gamète Résumé : "The species-mixed Pilosella populations comprising diploid sexual and polyploid facultatively apomictic biotypes were studied in Bulgaria. Parentage of co-occurring recent hybrids was inferred from a combination of morphology and ploidy level that corresponded to simple/multiple crosses of basic species via either reduced or unreduced gametes. The flow cytometric seed screening illustrated the capacity for heteroploid hybridization both in open-pollinated plants in the mixed-ploidy populations and in crossing experiments. The diploid sexual species in Bulgaria have a limited impact on interspecific hybridization, and simple inter-cytotype hybrids are only sporadically formed. The origin of the most common hybrids in Bulgaria that are apomictic and retain the pentaploid/hexaploid ploidy level of a co-occurring putative apomictic parent remains unclear. The absence of stabilized hybridogeneous species and scarcity of commonly hybridizing polyploid sexual biotypes are crucial attributes that distinguish the Pilosella populations in Bulgaria from those in the Czech Republic and Germany. No recent high-polyploid hybrids of 2n + n origin that would potentially become drivers of ongoing hybridization in the mixed sexual-apomictic Pilosella populations similar to those in Central Europe have been recorded in Bulgaria. The pattern of co-occurring cytotypes in Bulgaria likely limits interspecific hybridization due to stronger ploidy barriers." (source : auteurs) Type de publication : périodique Référence biblio : Krahulcová A., Krahulec F., Vladimirov V., 2018 - Impact of interspecific hybridization within a polyploid agamic complex of Pilosella (Asteraceae, Cichorieae) in Bulgaria compared with Central Europe. Willdenowia, 48 (3) : 345-362. Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=68062
in Willdenowia > vol. 48, n°3 (Année 2018) . - pp. 345-362[article]Exemplaires
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Titre : Northern Hemisphere disjunctions in Lactuca (Cichorieae, Asteraceae) : independent Eurasia to North America migrations and allopolyploidization Type de document : Livre Auteurs : Kathy E. Jones, Auteur ; Edward E. Schilling, Auteur ; Elisabete F. Dias, Auteur ; Norbert Kilian, Auteur Année de publication : 2018 Article en page(s) : pp. 259-284 Langues : Anglais Catégories : [Espèces (in biblio)] Lactuca
[Thèmes] BiogéographieMots-clés : Cichorieae allopolyploïdie analyse des temps de divergence hémisphère nord phylogénétique disjonction des plantes Résumé : "The Lactucalineage is one of nine lineages in the lettuce subtribe (Cichorieae, Asteraceae) distributed in Europe, Africa, Asia and North America. Within the Lactucalineage two clades show disjunct Eurasian-North American distributions. One disjunct clade consists of diploids (x= 8) and allotetraploids (x= 17), the former restricted to Eurasia and the latter to North America and the Azores. In contrast, members of the other Eurasian-North American disjunct clade are all diploid (x= 9), like the remainder of the Lactucalineage (diploid,x= 8 or 9). The aims of the present study were to investigate the migration pathways that led to the disjunct distributions of these two Eurasian-North American clades and the potential progenitors of the allopolyploid taxa. We conducted deep taxon sampling and multi-locus phylogenetic analyses using nuclear ribosomal DNA (ETS and ITS), a low-copy nuclear marker (A44) and five non-coding plastid markers. Divergence time estimations with BEAST and ancestral biogeographic estimations with BioGeoBEARS suggested that both lineages reached North America by the late Miocene. Cloning of the A44 region revealed two sequence copies within allopolyploid individuals that were resolved in divergent clades and this helped to identify potential progenitors. We provide competing hypotheses for the progenitor species and biogeographic pathways that gave rise to the allotetraploid lineage, and we propose a North American origin for the Azorean endemic. Taxonomic conclusions includeL. raminifoliavar.mexicanabeing raised to specific rank with the nameL. brachyrrhynchaand the alleged endemicL. jamaicensisin fact represents the SE AsianL. indica, introduced to Jamaica." (source : auteurs) Type de publication : périodique Référence biblio : Jones K., Schilling E., Dias E., Kilian N., 2018 - Northern Hemisphere disjunctions in Lactuca (Cichorieae, Asteraceae) : independent Eurasia to North America migrations and allopolyploidization. Willdenowia, 48 (2) : 259-284. Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=68060
in Willdenowia > vol. 48, n°2 (Année 2018) . - pp. 259-284[article]Exemplaires
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Titre : Taxonomic study on the Greek endemic genus Hymenonema (Asteraceae : Cichorieae), using morphological and karyological traits Type de document : Livre Auteurs : Eleni Liveri, Auteur ; Pepy Bareka, Auteur ; Georgia Kamari, Auteur Année de publication : 2018 Article en page(s) : pp. 5-21 Langues : Anglais Catégories : [Espèces (in biblio)] Asteraceae
[Thèmes] TaxonomieMots-clés : Cichorieae Compositae Hymenonema morphologie distribution plante endémique Résumé : "Hymenonema is a Greek endemic genus consisting of two species, H. laconicum and H. graecum, occurring in the lowlands of S Peloponnisos and on most of the C Aegean islands, respectively. Morphological investigation of 20 gatherings covering the entire distribution range revealed clear morphological differences between the two species, mainly in pappus, achenes, anther tube, ligules and basal leaf characters. A corresponding emended identification key to the species is given. Karyological investigation of 11 accessions included karyotypes, idiograms and karyological indices for both species. Six karyomorphological parameters were also statistically analysed. Populations with intermediate morphological characters between the two species are recorded for the first time and their relationship with the typical two species is discussed. The geographical distribution of the genus is mapped and doubtful locations are commented on. The cytotaxonomic data and the geographical distribution of the species support the characterization of H. laconicum and H. graecum as schizoendemics. The conservation status of both species is suggested as Vulnerable (VU) according to IUCN criteria." (source : auteurs) Type de publication : périodique Référence biblio : Liveri E., Bareka P., Kamari G., 2018 - Taxonomic study on the Greek endemic genus Hymenonema (Asteraceae : Cichorieae), using morphological and karyological traits. Willdenowia, 48 (1) : 5-21. Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=67387
in Willdenowia > vol. 48, n°1 (Année 2018) . - pp. 5-21[article]Exemplaires
Cote Localisation Disponibilité P0170 Brest Exclu du prêt
