Biologia reprodutiva do bacuri (Platonia insignis Mart.) em vegetação secundária na zona bragantina

Abstract

The bacuriuri tree (Platonia insignis Mart., Clusiaceae) is a large fruit tree native to the Amazon, found in dryland forests in Pará, mainly on the island of Marajó and in the Salgado region as far as Maranhão, Goiás and Mato Grosso, on soils that are often not suitable for cultivation with other crops. The fruit has potential due to the organoleptic properties of the pulp. Currently its exploitation is the basis of extractivism for the regional market. This research aimed to characterize the reproductive biology of the bacuriuri, because studies are essential for the management and preservation of the species. The research was conducted in an area of secondary vegetation in the Bragantina zone, municipality of Bragança, Pará state, Brazil, from September to October 2000. Seven trees were marked for floral observation as to development and floral events. Flowers were collected for morphological description using a magnifying glass. The visiting agents were observed as to behavior and habit during the daytime period and collected for identification purposes in family, genus, and species at the Laboratory of Zoology of the Museu Paraense Emílio Goeldi. It was found that the flower is solitary, white, pinkish, situated terminally on the branches, pedunculate, asymmetric, acyclic, diperianth, heteroclanous, hermaphrodite, without bracts, pentamerous with fleshy petals, with internal and external striations, dialipetal corolla, regular, calyx disepalous, regular, androceous dialistemone, regular, polystemone, hypogynous, with gynecium sincarpic, pentacarpellate, stigma pentapartite, axial placentation, anther apiciphyllous, longitudinally dehiscent, introrsal and with only one teak. Before and diurnal usually in the first hours of the day (7 - 8 h), flower time around ten days and stigma receptivity between (15 - 17 h). The most frequent insects were bees acting as pollen and nectar collectors and coleopterans acting as predators. It was concluded that bees are probably the most frequent agents contributing to pollination syndrome.