Herkogamy and Mating Patterns in the Self-compatible Daffodil Narcissus longispathus
2005
Medrano, Mónica | Herrera, Carlos M. | Barrett, Spencer C.H.
• Background and Aims Floral design in self-compatible plants can influence mating patterns. This study invest- igated Narcissus longispathus, a self-compatible bee-pollinated species with wide variation in anther–stigma separation (herkogamy), to determine the relationship between variation in this floral trait and the relative amounts of cross- and self-fertilization. • Methods Anther–stigma separation was measured in the field in six populations of N. longispathus from south- eastern Spain. Variation in herkogamy during the life of individual flowers was also quantified. Multilocus out- crossing rates were estimated from plants differing in herkogamy using allozyme markers. • Key Results Anther–stigma separation varied considerably among flowers within the six populations studied (range = 1–10 mm). This variation was nearly one order of magnitude larger than the slight, statistically non-significant developmental variation during the lifespan of individual flowers. Estimates of multilocus outcrossing rate for different herkogamy classes (tm range = 0•49–0•76) failed to reveal a monotonic increase with increasing herkogamy. • Conclusions It is suggested that the lack of a positive relationship between herkogamy and outcrossing rate, a result that has not been previously documented for other species, could be mostly related to details of the foraging behaviour of pollinators.
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