Biologia da polinização de Byrsonima intermedia A. Juss. (“Murici”): floração, visitantes florais e sistema reprodutivo, em área de cerrado no distrito de itahum, município de Dourados-MS

Abstract

The interactions between plants and pollinators are vital to the structural and functional integrity of natural ecosystems, as well as to maintain or increase production of food for humans. 75% of Cerrado plant species are pollinated exclusively, primarily or secondarily by bees. The Cerrado has a high biological diversity and a great number of endemic species genuinely Brazilian and in the last 35 years, more than half of its area has been transformed into pastures, grain crops and other uses. Mapighiaceae The family is widely distributed in Neotropical regions, especially in America. The genus Byrsonima, popularly known as "Murici", fleshy fruit, is inserted in the Brazilian savanna. The flowers of Byrsonima intermedia A. Juss. are yellow, cyclical, hermaphrodites, diclamídeas, zygomorphic symmetry, gathered in inflorescences panicles and calyx glands in 10 (elaiophores), two on each sepal. Several papers address the reproductive biology of native species of the Malpighiaceae family, especially Byrsonima, summarize the diversity of floral visitors with main occurrence of the tribe Centridini individuals (collected oil), and other groups of bees, noting that the supply of oil and pollen by these plants ensures a natural pollination is essential for the formation of fruit. This work aimed to study and learn about the development of “Murici” (phenology and floral biology), to identify visitors to the flowers the bees, evaluate the behavior of foraging in the flowers and to evaluate the reproductive system of a plant located in the Cerrado region, District of Itahum, the city of Dourados-MS. We evaluated a total of 27 individuals of B. intermedia in the study area, between the months of nov./2009 to apr./2011, and according to the frequencies of individuals and focuses on the budding phenophases, deciduous, producing buds, blossoms and fruit. Peak flowering occurred in the months from December to February, and more buttons seen at the beginning of anthesis occurred at 11h30min. We totaled 65 hours of collection and observations of floral visitors in the midst of a period of intense flowering of the population of B. intermedia. For parameters of faunistic analysis were estimated Richness (S), Frequency, Constancy and Dominance. We sampled 344 bees, classified in 13 different species, into 6 distinct genera contained in two families: Apidae and Halicitidae. Of these nine species belonged to the tribe Centridini, representing 80,52% of all individuals. The main pollinator of "Murici," keeping in view the behavior observed high frequency of pollination and the floral visits was Epicharis (Triepicharis) sp2 (39,52%). B. intermedia is a species with selfcompatibility, but due to the effectiveness of pollinators is clear, given the reproductive success obtained by cross-pollination, not only superior to the method of natural pollination (control). The study of periods of supply of floral resources "Murici", and the activity of the community of visitors, gives us an important clue to the functions of the pollination process for the proper management of natural ecosystems, since these also increase pollinator production in growing areas.