Fenologia, ecologia da polinização e reprodução em populações de Begonia saxicola A. DC (Begoniaceae) em área de Brejo de altitude no Agreste Pernambucano

Abstract

Aspects related to floral biology, of a plant community provides subsidies for plant- animal interaction, as it provides an important tool for understanding the reproduction of plants and spatio-temporal organization, of the resources available in the environment to associated animals. In this study, we present data on phenological patterns and their relationship with abiotic factors, floral visitors, as well as aspects of the floral and reproductive biology of the population of Begonia saxicola, occurring in a swamp in the state of Pernambuco, highlighting the importance of the interaction of species with its pollinating agents. The leaf fall vegetative phenophase was the most regular, being recorded in the two years peaks in December corresponding to the dry season with ca. 80% of individuals in this phenophase. Budding phenophase lasted an average of 30 days, with a peak in May (rainy season). The peak in bud phenophase for male flowers in the two years of study showed peaks in July (82.5% and 83.3%), however, the button phenophase for female flowers, in the two years of studies, peaked in August. The flowering of B. saxicola lasted an average of three months and the fruits began their development in mid-August, at the beginning of the dry season. The species is monoecious, showing dyasium-like, cuminous inflorescences, with daytime anthesis, occurring in the early hours of the morning. Begonia saxicola have medium flowers (12- 17 mm), with distinct floral odors, between staminate (floral) and pistilate (sweet) flowers. In experiments on apomixis, they showed that this type of reproduction does not occur. In the flowers that were self-pollinated manually pollinated (geitonogamy) with endogenous pollen, fruit development did not occur, but those pollinated with exogenous pollen developed fruits. There was also no fruit development due to anemophilia. Two species of bees were observed, collected and identified during visits to the flowers, representatives of the Apidae family (Trigona spinipes; Apis melífera), one of the fly and the beetle. Apis mellifera and the other species of fly and beetle did not pollinate, being classified as a pollen plunderer, however T. spinipes was registered, making visits in both floral types. The reflectance of the different floral structures was considerably similar between the two floral types of the species. Modeling the color reflectance in the hexagon of the bee revealed that the color locations of the anther and the stigma were plotted in the same UV-green color space as the bees, while the tepals were traced in the achromatic space.