Intrafloral Color Modularity in a Bee-Pollinated Orchid

Autor(es)

Bignelli Valente Aguiar, Joao Marcelo Robazzi ^[1] ; Maciel, Artur Antunes ^[2] ; Santana, Pamela Cristina ^[3] ; Telles, Francismeire Jane ^[2] ; Bergamo, Pedro Joaquim ^[4] ; Oliveira, Paulo Eugenio ^[5] ; Garcia Brito, Vinicius Lourenco ^[5]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Biol, Programa Posgrad Entomol, Ribeirao Preto - Brazil

^[2] Univ Fed Uberlandia, Inst Biol, Programa Posgrad Ecol & Conservacao Recursos Nat, Uberlandia, MG - Brazil

^[3] Univ Sao Paulo, Dept Ecol, Programa Posgrad Ecol, Sao Paulo - Brazil

^[4] Inst Pesquisas Jardim Bot Rio de Janeiro, Rio De Janeiro - Brazil

^[5] Univ Fed Uberlandia, Inst Biol, Uberlandia, MG - Brazil

• Tipo de documento: Artigo Científico
• Fonte: FRONTIERS IN PLANT SCIENCE; v. 11, NOV 9 2020.
• Citações Web of Science: 0

Resumo

Flower color has been studied in different ecological levels of organization, from individuals to communities. However, it is unclear how color is structured at the intrafloral level. In bee-pollinated flowers, the unidirectional gradient in color purity and pollen mimicry are two common processes to explain intrafloral color patterns. Considering that floral traits are often integrated, usually reflecting evolutionary modules under pollinator-mediated selection, we hypothesize that such intrafloral color patterns are structured by intrafloral color modules as perceived by bee color vision system. Here, we studied the tropical bee-pollinated orchid Cattleya walkeriana, given its intrafloral color complexity and variation among individuals. Considering bee color vision, we investigated if intrafloral color modules arose among intrafloral patches (tip or base of the sepals, petals, and labellum). We expected a separate color module between the labellum patches (the main attractive structure in orchids) and petals and sepals. We measured the color reflectance and calculated the photoreceptor excitation, spectral purity, hue, and the chromatic contrast of the floral structures in the hexagon color model. Spectral purity (saturation) was higher in the labellum tip in comparison to petals and sepals, generating a unidirectional gradient. Labellum base presented a less saturated yellow UV-absorbing color, which may reflect a pollen mimicry strategy. C. walkeriana presented three intrafloral color modules corresponding to the color of petals and sepals, the color of the labellum tip, and the color of labellum base. These color modules were unrelated to the development of floral structures. Given the importance of intrafloral color patterns in bee attraction and guidance, our results suggest that intrafloral patterns could be the outcome of evolutionary color modularization under pollinator-mediated selection. (AU)

• Processo FAPESP: 19/20408-0 - Efeito de agrotóxicos no aprendizado e memória de abelhas nativas do Brasil
• Beneficiário: João Marcelo Robazzi Bignelli Valente Aguiar
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado