Do consecutive flower visits within a crown diminish fruit set in mass-flowering Hancornia speciosa (Apocynaceae)?
Hancornia speciosa is a self-incompatible, mass-flowering, sphingophilous fruit crop (mangaba) of northeast and central Brazil. The flowers have a precise pollination apparatus, which optimizes pollen transfer between flower and pollinator. While the pollination mechanism avoids self-pollination, mass-flowering promotes geitonogamy. During a flower visit, almost half of the exogenous pollen grains adhering to the proboscis are deposited on the stigma surface. A pollination experiment with a nylon thread simulating six consecutive flower visits within a crown revealed that only the first two flowers visited (positions 1 and 2) are highly likely to set fruit. Super-production of flowers, and consequently obligate low fruit set, seem to be part of the reproductive strategy of the obligate outcrossing plant, Hancornia speciosa.
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Programa de Pós-Graduação em Biologia Vegetal, Universidade Federal de Pernambuco, Brazil.
Oliveira
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Schlindwein
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D000818:Animals; D029062:Apocynaceae / Q000254:growth & development / Q000502:physiology*; D035264:Flowers / Q000502:physiology*; D005638:Fruit / Q000254:growth & development*; D007313:Insecta / Q000502:physiology*; D009055:Mouth / Q000502:physiology; D054817:Pollination; D013559:Symbiosis / Q000502:physiology