Reproductive success of four species of Eugenia L. (Myrtaceae)

Abstract

Eugenia uniflora, E. punicifolia, E. neonitida and E. rotundifolia are perennial species, usually shrubs, which occur in the restinga of the Grumari Natural Municipal Park, in western Rio de Janeiro, Brazil. They have Papaver-type pollen-flowers that are hermaphrodite, polystemonous and pollinated mainly by bees. An assessment of the breeding systems showed that only E. uniflora and E. punicifolia are self-compatible. The fruit/flower, seed/ovule and seed/fruit ratios were calculated for each species. Fruit and seed predators were identified and predation rates were estimated. Total reproductive success for each species in the restinga was extremely low. In order to have one viable seed free from herbivore attack at the end of the reproductive process, the species would need to produce 312.5 E. uniflora, 9090.9 E. neonitida, 11111.1 E. punicifolia and 19230.8 E. rotundifolia flowers. In short, the reproductive success of the four species is affected by pollination efficiency, low seed/ ovule ratios and mainly, high predation rates. Mass flowering strategy in these species can minimize low reproductive efficiency, thus ensuring the maintenance of population dynamics.