Caracterização da Coloração de Richardia grandiflora (Cham. & Schltdl.) Steud. de acordo com a visão de himenópteros

Abstract

Herbaceous plants play an important role in forest ecosystems, especially in relation to the interaction with floral visitors. Pollination is an essential ecological process for the reproduction of most Angiosperms, considered a mutualistic interaction, that is, it provides benefits to the participants, increasing the adaptive value (fitness) of both. The relationship between flower and visitor is established, most of the time, through an attraction (resource). Bees are by far the best-studied pollinators for physiology and mechanisms related to vision, as well as color preferences. These visitors also differ greatly in terms of behavior and use a number of factors to choose the flowers they visit, such as the number of available resources, flower handling time and energy spent during foraging. Although other causes are suggested to explain the variation in colors and patterns in flowers, it is certain that the interaction with floral visitors exerts the greatest selective pressure on these characteristics. Few studies have addressed the relationship between flower color change and pollinator vision. day, identify whether floral visitation can influence the color change and whether the color change would be visible by the visual system of bees. The study was carried out in March 2022, at the Federal University of Rio Grande do Norte (UFRN). A total of 135 flowers were collected. To measure the coloration of flowers and leaves, a USB4000 UV-VIS spectrophotometer (Ocean Optics, Inc.) and the SpectraSuit program (Ocean Optics, Inc.) were used. For the processing and analysis of the reflectance spectra, the Chittka color hexagon model was used and to verify if there was a color change, chromatic contrast values were calculated. Despite the modeling results of the study indicating that the flowers of Richardia grandiflora present themselves to their pollinators in the blue/UV range, with differences in the spectrum and in the percentage of reflectance, it was not possible to state whether there is a pattern of color change in the flower of Richardia grandiflora throughout the day in the view of these animals, as it seems to be for the human view.