Résumé
In plant species with an obligate species-specific pollinator, gamete encounter is a critical phase in the success of reproductive strategies. One of the key factors in the success of gamete encounter, the length of female receptivity, has been rarely studied experimentally. In Ficus species (Moraceae), each exclusively associated with its specific pollinating wasp, the receptive female phase of individual syconia was believed to last only a few days. This estimate, based on field observations of pollinator arrivals, neglected the possibility that unpollinated syconia may remain receptive for a prolonged period. In two distantly related fig species (F. carica and F. aurea), we measured experimentally the duration of receptivity of individual syconia protected from pollinator visits. For these two species, receptivity lasted from 2 to 3 wk. Syconia pollinated at any time during this period of receptivity are capable of setting seeds. Furthermore, it has been assumed that female syconium receptivity stops quickly after pollinator visitation. Our experiments showed that syconia of both species are able to extend their receptive period for a few days longer when visited only by a single wasp. The demonstration of a long duration of female receptivity has important consequences for understanding the maintenance of the fig-wasp mutualism.