| Titre : |
Historical and molecular biogeography of prickly lettuce (L. serriola L.) and evoluation of hybridisation with the crop (L. sativa L.) |
| Type de document : |
texte imprimé |
| Auteurs : |
Luigi D'Andrea, Auteur ; Université de Neuchâtel. Faculté des sciences (Neuchâtel, Suisse), Organisme de soutenance |
| Année de publication : |
2006 |
| Importance : |
91 p. |
| Note générale : |
Thèse soutenue à l'Université de Neuchâtel.Faculté des sciences. Laboratoire de botanique évolutive le 24 mars 2006 et autorisée par le jury à la publication |
| Langues : |
Anglais (eng) |
| Catégories : |
[Espèces (in biblio)] Lactuca sativa L.
[Espèces (in biblio)] Lactuca serriola L.
|
| Mots-clés : |
hybridation pollen changement climatique pertubation biogéographie génétique des populations biologie moléculaire |
| Résumé : |
"Prickly lettuce (L. serriola) distribution has expanded throughout Europe during the past centuries. In the present thesis, we document its spread in time and space by the investigation of historical material. We show that the colonisation of Northern Europe occurred during the end of 18th century and the first decades of the 19th century. Most of Europe was colonised by the beginning of the 20th century. The colonisation is recent and several factors that could explain this massive spread are discussed, in particular the influence of environmental and socio-economic changes on the distribution of the species. This includes different factors as climate warning, globalisation of trade and travel, development of transportation networks and the increased availability of disturbed and ruderal habitats. Its expansion has also been documented using several molecular tools (nuclear microsatellites and chloroplast PCR-RFLPs). The genetic diversity of present wild populations collected all over Europe was analysed. The results were in accordance with the life history strategy of the species. We found a very strong population structure and most of the genetic variation was distributed between populations. A strong pattern of isolation by distance was found, mainly caused by low pollen flow between populations and confirmed by a very high overall inbreeding coefficient and very low amount of observed heterozygotes. No clear grouping patterns could be highlighted at the continental scale. The higher genetic diversity was found in South of France, northern Italy and eastern Europe, while less was present in Great Britain, north Scandinavia and Iberian Peninsula. Kriging of Gene Diversity showed a tendency of decrease westwards and northwards from Eastern Europe. Finally, we studied the hybridisation between prickly lettuce (L. serriola L.) and crop lettuce empirically, by planting the crop in the middle of two fields and wild plants at different distances from it, in two locations in Switzerland during the summer 2003 and 2004. These experiments were carried out in order to assess the risk of (trans)gene escape through pollen flow. Despite flowering mechanisms ensuring self-fertilisation in both species, hybridisation has been found to be the rule rather than the exception at close distances." (source : auteur) |
| Type de publication : |
thèse, mémoire, stage |
| Référence biblio : |
D'Andrea L., 2006 - Historical and molecular biogeography of prickly lettuce (L. serriola L.) and evoluation of hybridisation with the crop (L. sativa L.). Thesis. Neuchâtel : Université de Neuchâtel. Faculté des sciences, 91 p. |
| ID PMB : |
52682 |
| Permalink : |
http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=52682 |
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Historical and molecular biogeography of prickly lettuce (L. serriola L.) and evoluation of hybridisation with the crop (L. sativa L.) (2006)