Annals of Botany

Seasonal variation in selfing rate

Flowering plants display considerable variation in mating system, particularly the relative frequency of cross- and self-fertilization. The majority of estimates of outcrossing rate do not account for temporal variation, particularly during the flowering season.

Incarvillea sinensis
The showy floral displays of Incarvillea sinensis at the study site in Inner Mongolia, China.. Photo by Yin et al..

Yin et al. investigate seasonal variation in mating using genetic markers in Incarvillea sinensis (Bignoniaceae), a desert annual with showy, insect-pollinated flowers capable of delayed selfing. They report evidence of mixed mating but with a significant increase in selfing as pollinator visitation declined towards the end of the season. They suggest that delayed selfing provides reproductive assurance when harsh environments limit pollinator service.