Maintenance of mixed mating after the loss of self-incompatibility in a long-lived perennial herb.

Détails

ID Serval
serval:BIB_B061AA7F815B
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Maintenance of mixed mating after the loss of self-incompatibility in a long-lived perennial herb.
Périodique
Annals of Botany
Auteur(s)
Voillemot M., Pannell J.R.
ISSN
1095-8290 (Electronic)
ISSN-L
0305-7364
Statut éditorial
Publié
Date de publication
2017
Peer-reviewed
Oui
Volume
119
Numéro
1
Pages
177-190
Langue
anglais
Résumé
Many hermaphroditic plants avoid self-fertilization by means of a molecular self-incompatibility (SI) system, a complex trait that is difficult to evolve but relatively easy to lose. Loss of SI is a prerequisite for an evolutionary transition from obligate outcrossing to self-fertilization, which may bring about rapid changes in the genetic diversity and structure of populations. Loss of SI is also often followed by the evolution of a 'selfing syndrome', with plants having small flowers, little nectar and few pollen grains per ovule. Here, we document the loss of SI in the long-lived Spanish toadflax Linaria cavanillesii, which has led to mixed mating rather than a transition to a high rate of selfing and in which an outcrossing syndrome has been maintained.
We performed crosses within and among six populations of L. cavanillesii in the glasshouse, measured floral traits in a common-garden experiment, performed a pollen-limitation experiment in the field and conducted population genetic analyses using microsatellites markers.
Controlled crosses revealed variation in SI from fully SI through intermediate SI to fully self-compatible (SC). Flowers of SC individuals showed no evidence of a selfing syndrome. Although the SC population of L. cavanillesii had lower within-population genetic diversity than SI populations, as expected, population differentiation among all populations was extreme and represents an FST outlier in the distribution for both selfing and outcrossing species of flowering plants.
Together, our results suggest that the transition to SC in L. cavanillesii has probably been very recent, and may have been aided by selection during or following a colonization bottleneck rather than in the absence of pollinators. We find little indication that the transition to SC has been driven by selection for reproductive assurance under conditions currently prevailing in natural populations.

Mots-clé
Fruit set, Linaria cavanillesii, genetic diversity, mixed mating, outcrossing, pollen limitation, reproductive assurance, self-incompatibility, selfing syndrome
Pubmed
Web of science
Open Access
Oui
Création de la notice
17/02/2017 14:35
Dernière modification de la notice
20/08/2019 16:19
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