[article] | Titre : | Hybridization and Agamospermy of Bidens in Northwestern Ontario | | Type de document : | périodique | | Auteurs : | David R. Crowe, Auteur ; William H. Parker, Auteur | | Année de publication : | 1981 | | Article en page(s) : | pp. 749-760 | | Langues : | Anglais | | Catégories : | [Espèces (in biblio)] Bidens
[Espèces (in biblio)] Bidens cernua
[Espèces (in biblio)] Bidens connata
[Espèces (in biblio)] Bidens frondosa
[Espèces (in biblio)] Bidens vulgata
| | Mots-clés : | hybridation description critère de détermination comparaison d'espèces | | Résumé : | "Four weedy taxa of Bidens are common in Thunder Bay: B. cernua, B. connata, B. frondosa and B. vulgata. Since B. connata is intermediate in gross morphology and ecological preference between B. cernua and B. frondosa, and since it is only found in areas where B. cernua and B. frondosa are sympatric, an investigation was undertaken to determine whether B. connata is of hybrid origin (B. cernua × B. frondosa). Representative specimens of the 4 taxa were scored for 23 morphological characters, and these data were analyzed by Principal Coordinates Analysis. Seed germination and pollen viability were determined to be high with no significant differences among the 4 taxa. Morphological and cytological data suggest that B. connata (2n = 48) is the result of either a cross between an unreduced gamete of B. cernua (2n = 24) with a normal gamete of B. frondosa (2n = 48), or a cross between a 2n = 24 of B. frondosa with a typical gamete of B. cernua. Since B. connata shows no decrease in seed viability and apparently produces pollen by mitosis only, Thunder Bay populations of B. connata evidently comprise an agamic complex." (source : auteurs) | | Type de publication : | périodique | | Référence biblio : | Crowe D., Parker W., 1981 - Hybridization and Agamospermy of Bidens in Northwestern Ontario. Taxon, 30 (4) : 749-760. | | ID PMB : | 69284 | | DOI : | 10.2307/1220076 | | Permalink : | http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=69284 |
in Taxon > vol. 30, n°4 (Année 1981) . - pp. 749-760
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Affiner la rechercheUne adventice nouvelle pour le Nord-Ouest de la France : Bidens vulgata Greene (Composées) in Bulletin de la Société scientifique de Bretagne, tome 40, fasc. 1 et 2 (Année 1965)
