Titre
Ecological differentiation and diploid superiority across a moving ploidy contact zone.
Type
article
Institution
Externe
Auteur(s)
Buggs, R.J.
Auteure/Auteur
Pannell, J.R.
Auteure/Auteur
Liens vers les personnes
ISSN
0014-3820
Statut éditorial
Publié
Date de publication
2007
Volume
61
Numéro
1
Première page
125
Dernière page/numéro d’article
140
Peer-reviewed
Oui
Langue
anglais
Résumé
Plant polyploid complexes provide useful model systems for distinguishing between adaptive and nonadaptive causes of parapatric distributions in closely related lineages. Polyploidy often gives rise to morphological and physiological changes, which may be adaptive to different environments, but separate distributions may also be maintained by reproductive interference caused by postzygotic reproductive isolation. Here, we test the hypothesis that diploid and descendent polyploid races of the wind-pollinated herb Mercurialis annua, which are found in parapatry over an environmental gradient in northeast Spain, are differentiated in their ecophysiology and life history. We also ask whether any such differences represent adaptations to their different natural environments. On the basis of a series of reciprocal transplant experiments in the field, and experiments under controlled conditions, we found that diploid and polyploid populations of M. annua are ecologically differentiated, but that they do not show local adaptation; rather, the diploids have higher fitness than the polyploids across both diploid- and polyploid-occupied regions. In fact, diploids are currently displacing polyploids by advancing south on two separate fronts in Spain, and previous work has shown that this displacement is being driven to a large extent by asymmetrical pollen swamping. Our results here suggest that ecophysiological superiority of the diploids may also be contributing to their expansion.
PID Serval
serval:BIB_968FAF7296EE
PMID
Open Access
Oui
Date de création
2011-09-20T06:38:51.730Z
Date de création dans IRIS
2025-05-21T01:46:19Z