The divergence history of the perennial plant Linaria cavanillesii confirms a recent loss of self-incompatibility

M. Voillemot (1) , Q. Rougemont (2) , Camille Roux (3, 1) , J. R Pannell (1)

1 DEE - Department of Ecology and Evolution [UNIL, Lausanne] = Département d'écologie et évolution
2 IBIS - Institut de Biologie Intégrative et des Systèmes
3 Evo-Eco-Paléo (EEP) - Évolution, Écologie et Paléontologie (Evo-Eco-Paleo) - UMR 8198

Many angiosperms prevent inbreeding through a self-incompatibility (SI) system, but the loss of SI has been frequent in their evolutionary history. The loss of SI may often lead to an increase in the selfing rate, with the purging of inbreeding depression and the ultimate evolution of a selfing syndrome, where plants have smaller flowers with reduced pollen and nectar production. In this study, we used approximate Bayesian computation (ABC) to estimate the timing of divergence between populations of the plant Linaria cavanillesii that differ in SI status and in which SI is associated with low inbreeding depression but not with a transition to full selfing or a selfing syndrome. Our analysis suggests that the mixed-mating self-compatible (SC) population may have begun to diverge from the SI populations around 2810 generation ago, a period perhaps too short for the evolution of a selfing syndrome. We conjecture that the SC population of L. cavanillesii is at an intermediate stage of transition between outcrossing and selfing.

Mots clés: approximate Bayesian computation simulations; mating system transition; population divergence; purging; self-compatibility; selfing syndrome

Domaines: Génétique des populations [q-bio.PE]

M. Voillemot, Q. Rougemont, Camille Roux, J. R Pannell. The divergence history of the perennial plant Linaria cavanillesii confirms a recent loss of self-incompatibility. Journal of Evolutionary Biology, 2018, 31 (1), pp.136 - 147. ⟨10.1111/jeb.13209⟩. ⟨hal-01713172⟩