[article]
Titre : | Studies on variation and evolution in Centaurium erythraea Rafn and C. littorale (D. Turner) Gilmour in the British Isles, 2. Cytology | Type de document : | Livre | Auteurs : | R. A. E. Ubsdell, Auteur | Année de publication : | 1976 | Article en page(s) : | pp. 33-43 | Langues : | Anglais | Catégories : | [ZG] Royaume-Uni [Espèces (in biblio)] Centaurium erythraea [Espèces (in biblio)] Centaurium erythraea Raf. subsp. erythraea var. capitatum (Willd.) Melderis [Espèces (in biblio)] Centaurium littorale
| Mots-clés : | Centaurium erythraea Rafn subsp. erythraea var. subcapitatum | Résumé : | "Chromosome counts of Celllallrium erythraea Rafn and C. littorale (D. Turner) Gilmour from northern Europe are given. They confirm those made by Zeltner (1970) and show both species to be tetraploid (211 = 40) with regular meiosis. Morphologically intermediate (Ft-like) plants from Ainsdale, S. Lancs. (v.c. 59), were found to be tetraploid with irregular meiosis. They were almost sterile, as were Ft-like plants from Newborough, Anglesey (v.c. 52), and were almost identical in their morphology and cytology to artificial Fl hybrids. Morphologically intermediate plants from northern Germany were found to be tetraploid, but with regular meiosis and a high fertility. It is suggested that they are stabilized derivatives of the F 1 hybrid. Hybrid plants from St Annes, W. Lancs. (v.c. 60), which resemble C. erythraea in their morphology and are probably backcrosses to this species, were found to be tetraploid with regular meiosis and a high fertility. Hybrid plants from Ainsdale, Freshfield and Hightown, S. Lancs. (v.c. 59), which closely resemble C. littorale in their morphology, were found to be hexaploid (211 = 60) with regular meiosis and a high fertility. They are shown to breed true, to be isolated from their tetraploid parents and other (tetraploid) hybrids by a difference in chromosome number, and to be able to compete successfully with their parents. They are, therefore, considered to constitute a new species, and a possible origin involving hybridization and polyploidy is discussed." (source : auteur) | Type de publication : | périodique | Référence biblio : | Ubsdell R.-A.-E., 1976 - Studies on variation and evolution in Centaurium erythraea Rafn and C. littorale (D. Turner) Gilmour in the British Isles, 2. Cytology. Watsonia, 11 : 33-43. | ID PMB : | 69463 | En ligne : | http://archive.bsbi.org.uk/Wats11p33.pdf | Format de la ressource électronique : | document | Permalink : | http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=69463 | in Watsonia > vol. 11 (Année 1976) . - pp. 33-43
[article]
Studies on variation and evolution in Centaurium erythraea Rafn and C. littorale (D. Turner) Gilmour in the British Isles, 2. Cytology [Livre] / R. A. E. Ubsdell, Auteur . - 1976 . - pp. 33-43. Langues : Anglais in Watsonia > vol. 11 (Année 1976) . - pp. 33-43 Catégories : | [ZG] Royaume-Uni [Espèces (in biblio)] Centaurium erythraea [Espèces (in biblio)] Centaurium erythraea Raf. subsp. erythraea var. capitatum (Willd.) Melderis [Espèces (in biblio)] Centaurium littorale
| Mots-clés : | Centaurium erythraea Rafn subsp. erythraea var. subcapitatum | Résumé : | "Chromosome counts of Celllallrium erythraea Rafn and C. littorale (D. Turner) Gilmour from northern Europe are given. They confirm those made by Zeltner (1970) and show both species to be tetraploid (211 = 40) with regular meiosis. Morphologically intermediate (Ft-like) plants from Ainsdale, S. Lancs. (v.c. 59), were found to be tetraploid with irregular meiosis. They were almost sterile, as were Ft-like plants from Newborough, Anglesey (v.c. 52), and were almost identical in their morphology and cytology to artificial Fl hybrids. Morphologically intermediate plants from northern Germany were found to be tetraploid, but with regular meiosis and a high fertility. It is suggested that they are stabilized derivatives of the F 1 hybrid. Hybrid plants from St Annes, W. Lancs. (v.c. 60), which resemble C. erythraea in their morphology and are probably backcrosses to this species, were found to be tetraploid with regular meiosis and a high fertility. Hybrid plants from Ainsdale, Freshfield and Hightown, S. Lancs. (v.c. 59), which closely resemble C. littorale in their morphology, were found to be hexaploid (211 = 60) with regular meiosis and a high fertility. They are shown to breed true, to be isolated from their tetraploid parents and other (tetraploid) hybrids by a difference in chromosome number, and to be able to compete successfully with their parents. They are, therefore, considered to constitute a new species, and a possible origin involving hybridization and polyploidy is discussed." (source : auteur) | Type de publication : | périodique | Référence biblio : | Ubsdell R.-A.-E., 1976 - Studies on variation and evolution in Centaurium erythraea Rafn and C. littorale (D. Turner) Gilmour in the British Isles, 2. Cytology. Watsonia, 11 : 33-43. | ID PMB : | 69463 | En ligne : | http://archive.bsbi.org.uk/Wats11p33.pdf | Format de la ressource électronique : | document | Permalink : | http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=69463 |
|