Do floral and niche shifts favour the establishment and persistence of newly arisen polyploids? A case study in an Alpine primrose.

Détails

ID Serval
serval:BIB_DC5CD2CA43AC
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Do floral and niche shifts favour the establishment and persistence of newly arisen polyploids? A case study in an Alpine primrose.
Périodique
Annals of Botany
Auteur(s)
Casazza G., Boucher F.C., Minuto L., Randin C.F., Conti E.
ISSN
1095-8290 (Electronic)
ISSN-L
0305-7364
Statut éditorial
Publié
Date de publication
2017
Peer-reviewed
Oui
Volume
119
Numéro
1
Pages
81-93
Langue
anglais
Résumé
Polyploidization plays a key role in plant evolution. Despite the generally accepted 'minority-cytotype exclusion' theory, the specific mechanisms leading to successful establishment and persistence of new polyploids remain controversial. The majority of newly formed polyploids do not become established, because they are less common, have fewer potential mates or may not be able to compete successfully with co-occurring progenitors at lower ploidy levels. Changes in floral traits and ecological niches have been proposed as important mechanisms to overcome this initial frequency-dependent disadvantage. The aim of this study was to determine whether dodecaploids of the heterostylous P. marginata differ from their hexaploid progenitors in P. marginata and P. allionii for selected floral traits and ecological preferences that might be involved in establishment and persistence, providing a possible explanation for the origin of polyploidized populations.
Floral morphological traits and ecological niche preferences among dodecaploids and their hexaploid progenitors in P. marginata and P. allionii ,: all restricted to the south-western Alps, were quantified and compared KEY RESULTS: Differences in floral traits were detected between dodecaploids and their closest relatives, but such differences might be too weak to counter the strength of minority cytotype disadvantage and are unlikely to enable the coexistence of different cytotypes. Furthermore, the results suggest the preservation of full distyly and no transition to selfing in dodecaploids. Finally, dodecaploids occur almost exclusively in environments that are predicted to be suitable also for their closest hexaploid relatives.
In light of the results, P. marginata dodecaploids have probably been able to establish and persist by occupying geographical areas not yet filled by their closest relatives without significant evolution in their climatic and pollination niches. Dispersal limitation and minority-cytotype exclusion probably maintain their current range disjunct from those of its close relatives.

Mots-clé
Ecological niche, minority-cytotype exclusion, pollinator shift, polyploidy, Primula allionii Loisel, Primula marginata Curtis
Pubmed
Web of science
Open Access
Oui
Création de la notice
03/01/2017 18:22
Dernière modification de la notice
20/08/2019 16:01
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