The role of a mixed mating system in the reproduction of a Mediterranean subshrub (Fumana hispidula, Cistaceae)

Knowledge about mixed mating systems can improve our understanding of the evolutionary dynamics of reproductive systems. Here we report a study of the pollination system (floral and reproductive biology, pollen limitation and stigmatic pollen load, floral visitors and inbreeding depression) of Fumana hispidula, a Mediterranean subshrub belonging to a species group with a strong selfing tendency. Autonomous self-pollination, hand self- and hand cross-pollination, open pollination and controls yielded fruits (0.28, 0.65, 0.68, 0.38, and 0.67, respectively); however, autonomous self-pollination resulted in the lowest fruit set. All individuals were fully self-compatible but we found great inter-individual variation in autonomous self-pollination ability, which was probably related to a variable expression of herkogamy degree. Inbreeding depression was low (0.040 for fruit set, 0.015 for seed set and ?0.026 for seed mass). The pollen supplementation experiment did not reveal pollen limitation and pollinators were seen visiting the flowers during the observation periods. These results support the idea that F. hispidula has a mixed mating strategy, which represents a successful reproduction mode in their patchy habitats.