[article]
| Titre : |
Genetic variation and natural hybridization between Orchis laxiflora and Orchis palustris (Orchidaceae) |
| Type de document : |
texte imprimé |
| Auteurs : |
Paola Arduino, Auteur ; Federica Verra, Auteur ; Rossella Cianchi, Auteur ; Walter Rossi, Auteur ; Bruno Corrias, Auteur ; Luciano Bullini, Auteur |
| Année de publication : |
1996 |
| Langues : |
Anglais (eng) |
| Catégories : |
[Espèces (in biblio)] Orchis laxiflora
[Espèces (in biblio)] Orchis palustris
[Thèmes] Plante à forte valeur patrimoniale
[Thèmes] Taxonomie
|
| Mots-clés : |
génétique hybridation |
| Résumé : |
"Genetic divergence between population samples ofOrchis laxiflora and ofO. palustris from various European locations was studied by electrophoretic analysis of 25 enzyme loci. An average genetic distance of DNei = 1.24 was found between the two taxa, with 12 out of 25 loci showing alternative alleles (diagnostic loci). Genetic heterogeneity was observed within bothO. laxiflora andO. palustris, when northern and southeastern populations were compared, being lower in the former taxon (D = 0.06), than in the latter (D = 0.16). Karyologically, 2n = 36 was found for bothO. laxiflora andO. palustris. O. laxiflora andO. palustris produce hybrids, described asO. ×intermedia. Genotype analysis of several sympatric samples showed the presence of hybrid zones, including F1 hybrids and, in low proportions, recombinant classes, putatively assigned to Fn and backcrosses, as well as a few introgressed individuals of both taxa. These data indicate that hybrids are only partially fertile, with a very limited mixing up of the two parental gene pools; this is also shown by the lack of significant lowering of genetic distances when sympatric and allopatric heterospecific samples are compared. Accordingly,O. laxiflora andO. palustris form a syngameon; nevertheless they can be considered as good taxonomic species, with virtually distinct gene pools, which evolve independently. The genetic variability inO. laxiflora andO. palustris is remarkably low (H¯ e = 0.05 andH¯ e = 0.02, respectively). In particular, nearly complete absence of polymorphic loci was found inO. palustris from northcentral Europe. Two hypotheses are considered to explain the low genetic variability of this endangered species." (source : auteurs) |
| Type de publication : |
périodique |
| Référence biblio : |
Arduino P., Verra F., Cianchi R., Rossi W., Corrias B., Bullini L., 2002 - Genetic variation and natural hybridization between Orchis laxiflora and Orchis palustris (Orchidaceae). Plant Systematics and Evolution, 202 : . |
| ID PMB : |
71104 |
| Permalink : |
http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=71104 |
in Plant Systematics and Evolution > vol. 202 (Année 1996)
[article]
|
Genetic variation and natural hybridization between Orchis laxiflora and Orchis palustris (Orchidaceae) in Plant Systematics and Evolution, vol. 202 (Année 1996)