Conservation Genetics

, Volume 11, Issue 2, pp 497–508

An experimental study of the S-Allee effect in the self-incompatible plant Biscutella neustriaca


  • Jean-Baptiste Leducq
    • Laboratoire Génétique et Evolution des Populations Végétales
  • Célia Chantal Gosset
    • Laboratoire Génétique et Evolution des Populations Végétales
  • Matthieu Poiret
    • Laboratoire Génétique et Evolution des Populations Végétales
  • Frédéric Hendoux
    • Conservatoire Botanique National de Bailleul, Hameau de Haendries
  • Xavier Vekemans
    • Laboratoire Génétique et Evolution des Populations Végétales
    • Laboratoire Génétique et Evolution des Populations Végétales
Research Article

DOI: 10.1007/s10592-010-0055-2

Cite this article as:
Leducq, J., Gosset, C.C., Poiret, M. et al. Conserv Genet (2010) 11: 497. doi:10.1007/s10592-010-0055-2


Homomorphic self-incompatibility (SI) evolved in many plant families to enforce selfing avoidance, and is controlled by a single multiallelic locus (the S-locus). In a fragmented landscape, strong variation in population size and in local density is expected to cause strong variation in allelic diversity at the S-locus, which could generate an Allee effect on female reproductive success by constraining compatible pollen availability. In this experimental study, we aimed at detecting this SI-specific Allee effect (or S-Allee effect) in the endangered species Biscutella neustriaca. We demonstrated the occurrence of a SI mating system in the species and determined compatibility relationships among genotypes through a large set of controlled pollinations. For the experiment, we chose three different pollen receptor genotypes, each compatible with respectively 100, 75 and 25% of four other genotypes, which constituted the pollen sources. We placed different ramets of each receptor at different distances from the pollen sources to control for pollen limitation due to low local density, and we measured the seed set on each receptor plant three times consecutively. Analyses performed with generalized linear mixed models showed that both the distance to the pollen sources and the mate availability due to SI had a significant effect on seed set, with a strong reduction observed when mate availability was limited to 25%. Our results suggest that pollen limitation due to a restriction in compatible mate availability could occur in small or scattered populations exhibiting low allelic diversity at the S-locus.


Allee effectPollen limitationMate availabilitySelf-incompatibilityGeneralized linear mixed modelBrassicaceae

Supplementary material

10592_2010_55_MOESM1_ESM.pdf (177 kb)
Supplementary material 1 (PDF 176 kb)

Copyright information

© Springer Science+Business Media B.V. 2010