Resumo

HOKCHE D, Omaira  e  RAMIREZ, Nelson. Reproductive biology and biomass floral allocation in Solanum gardneri  Sendth. (Solanaceae): an andromonoecious species. Acta Bot. Venez. [online]. 2006, vol.29, n.1, pp.69-88. ISSN 0084-5906.

    The breeding system and floral characteristics of Solanum gardneri Sendth., a woody shrub widely distributed in Venezuela, were investigated considering the floral dimorphism associated with the pistil length in order to know if this floral condition determines an andromonoic sexual system. Anthesis is diurnal; flowers offering only pollen as reward, and the pollinators are bees, belonging to the genera Augochloropsis, Centris, Exomalopsis and Xylocopa. S. gardneri has a xenogamous mating system, of a self-incompatible species, related to a high P/O ratio, associated with a high biomass allocation to male and attraction functions. Female sterility in short-style flower and significant differences between floral morphs in number and ovule size, and pollen size indicate the andromonocious condition of S. gardneri. The allocation invested in the male function and in the attraction structures promote outcrossing. The male function explains the relatively high fruit-set. The high ovule abortion level found has been associated to a better postcigotic resource allocation level and the higher seed number per fruit is probably related to the fruit dispersal strategy,which is ornitochory.

Palavras-chave : Andromonoecy; Floral biomass allocation; Floral dimorphism; Pollination; Reproductive biology; Self-incompatibility; Solanum; Venezuela.