A functional decomposition of sex inconstancy in the dioecious, colonizing plant Mercurialis annua.

Détails

ID Serval
serval:BIB_E5BB979AD936
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
A functional decomposition of sex inconstancy in the dioecious, colonizing plant Mercurialis annua.
Périodique
American Journal of Botany
Auteur(s)
Cossard G.G., Pannell J.R.
ISSN
1537-2197 (Electronic)
ISSN-L
0002-9122
Statut éditorial
Publié
Date de publication
2019
Peer-reviewed
Oui
Volume
106
Numéro
5
Pages
722-732
Langue
anglais
Résumé
Plants with separate sexes often show "inconstant" or "leaky" sex expression, with females or males producing a few flowers of the opposite sex. The frequency and degree of such inconstancy may reflect residual hermaphroditic sex allocation after an evolutionary transition from combined to separate sexes. Sex inconstancy also represents a possible first step in the breakdown of dioecy back to hermaphroditism. In the Mercurialis annua (Euphorbiaceae) species complex, monoecy and androdioecy have evolved from dioecy in polyploid populations. Here, we characterize patterns of sex inconstancy in dioecious M. annua and discuss how sex inconstancy may have contributed to the breakdown of separate sexes in the genus.
We measured sex inconstancy in three common gardens of M. annua over 2 years using a modification of Lloyd's phenotypic gender in terms of frequency and degree, with the degree calibrating inconstancy against the sex allocation of constant males and constant females, yielding a measure of gender that does not depend on the distribution of gender in the population.
Unusually for dioecious plants, the frequency of sex inconstancy in M. annua was greater in females, but its degree was greater for males in the 2 years of study. We suggest that this pattern is consistent with the maintenance of inconstancy in dioecious M. annua by selection for reproductive assurance under mate limitation.
Our study illustrates the utility of decomposing measures of sex inconstancy into its frequency and its degree and throws new light on the origin of variation in sexual systems in Mercurialis.
Mots-clé
Euphorbiaceae, androdioiecy, functional gender, leaky dioecy, monoecy, sexual system
Pubmed
Web of science
Création de la notice
03/06/2019 8:36
Dernière modification de la notice
20/08/2019 17:09
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