Format: ORAL

Ana Garca-Muoz1, Camilo Ferrn2, Celia Vaca-Benito1, M. Nazaret Martnez-Gmez1, Slvia Castro3, Mariana Castro3, Joo Loureiro3, A. Jess Muoz-Pajares1,4, Mohamed Abdelaziz1

1 University of Granada, Granada, Spain 2 University Rey Juan Carlos, Madrid, Spain 3 University of Coimbra, Coimbra, Portugal 4 Research Unit Modeling Nature, Universidad de Granada, Granada, Spain

The evolution of mating systems in plants is central to understanding the rise of their diversity on Earth. The transition towards self-fertilization is a well-known example of convergent evolution and, in fact, the opposite direction is expected to be forbidden according to evolutionary theories. The mating system is often shaped by the action of biotic drivers such as pollinators in outcrossing plants. Here, we suggest that the ploidy could also promote changes in the reproductive strategies through to its effect on traits related to pollination. To this end, we used several populations from the Erysimum incanum species complex which has been described as predominantly selfing. We performed over 7,000 controlled crosses to assess the inbreeding depression. In addition, we measured mating traits such as flower size, herkogamy, anther exertion and the relative investment between male and female reproductive investment (i.e. pollen-ovule ratio). We described three ploidy levels -the hexaploid level was previously unknown- and estimated the genomic diversity of each ploidy. We found significant differences in the self-pollination success among ploidies and, even, among populations within the same ploidy. A certain degree of inbreeding depression was present in higher ploidies, which were also accompanied by larger flowers with higher anther exposure, a more accentuated herkogamy and a higher allocation in pollen production related to the ovule amount. These findings suggest that ploidy could be promoting alternative reproductive strategies to selfing, driving mating system diversification within a selfing species, which has not been described in the wild before.