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Floral Biology and the reproductive system of Byrsonima coccolobifolia (Kunth) in an amazonian savanna

The reproductive biology of Byrsonima coccolobifolia was evaluated in a savanna area of State of Roraima, Brazil. This is a woody species of bushes and small trees 3m tall. The flowers are hermaphrodite, pentamerous, zygomorphic, arranged in a terminal inflorescence, produced in new sprouts. Five sepals form the calyx, each one with a pair of oil-producing glands, called elaiophores. The corolla is pale-pink and formed by five clawed and fringed petals, and the androecium is composed of ten stamens with yellow-colored anthers. The anthesis can be nocturnal or diurnal, which lasts for an average of 12 hours, and the flowers usually remain open and pretty for 15 more hours after the end of the process, when senescing begins. Two flowering periods were registered and the fire seems to be a factor environmental stimulator of this phonological phase. The predominant floral visitors were bees of the families Anthophoridae (Centris sp. and Xylocopasp.) and Apidae (Apis mellífera and Bombus sp.). Results of controlled pollination and the self-incompatibility index (ISI) suggest that the species presents protogynous behavior and is self-compatible, producing fruits in all self-pollination treatments in similar proportions as under natural pollination. The production of apomict fruits was not confirmed. However, the percentages of fruits formed under xenogamy treatments were significantly superior to the fruit-set in self-fertilization. This suggests that the species presents a mixed reproductive system with high allogamy and autogamy levels.

Byrsonima; murici; floral biology; reproductive system


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