Bitter melon is a monoecious and ruderal species of economic interest. The knowledge of its reproductive mechanisms is important for its conservation and management. The species floral biology, reproductive phenology, pollination, and breeding system were studied. The species has diclinous flowers, with diurnal anthesis. The period of flowering lasted around 100 days and its peak occurred in October. In the beginning of the flowering the species presents dicogamy of the protandry type. The female flowers do not produce nectar, while the male flowers produce nectar during the entire period of anthesis. There was identified a mimicry of the male flowers by the female flowers. Fruit formation occurred through crossed-pollination and self-pollination. The number of seeds in the fruits did not differ (H = 1.13; P > 0.05) among the type of pollination. The relation seed/egg was in the order of 80%. All floral visitors collected and observed on the flowers belong to the class Insecta. Diabrotica speciosa (Coleoptera, Chrysomelidae) was the most abundant species (40%) and the main pollinator of Momordica charantia in the study area. Other insects, however, as bees (Apoidea) and butterflies (Hesperiidae and Pieridae), were also observed in the flowers and can contribute as pollinators.
bitter melon; breeding system; floral biology; pollination
