What pollinators see does not match what they smell: Absence of color-fragrance association in the deceptive orchid Ionopsis utricularioides

Author(s)

Bignelli Valente Aguiar, Joao Marcelo Robazzi ^[1] ; Ferreira, Gabriel de Souza ^[2] ; Sanches, Patricia Alessandra ^{[3, 4]} ; Simoes Bento, Jose Mauricio ^[4] ; Sazima, Marlies ^[5]

Affiliation

^[1] Univ Estadual Campinas, Inst Biol, Programa Posgrad Ecol, BR-13083865 Campinas, SP - Brazil

^[2] Eberhard Karls Univ Tubingen, Senckenberg Ctr Human Evolut & Palaeoenvironm HEP, Sigwartstr 10, D-72076 Tubingen - Germany

^[3] Swiss Fed Inst Technol, Dept Environm Syst Sci, CH-8092 Zurich - Switzerland

^[4] Univ Sao Paulo, Escola Super Agr Luiz de Queiroz ESALQ, Dept Entomol & Acarol, BR-13418900 Piracicaba, SP - Brazil

^[5] Univ Estadual Campinas, Inst Biol, Dept Bot, BR-13083865 Campinas, SP - Brazil

• Document type: Journal article
• Source: Phytochemistry; v. 182, FEB 2021.
• Web of Science Citations: 0

Abstract

Many deceptive orchids present variation in floral color and fragrance. This might be advantageous for the plant, as it can disturb the associative avoidance learning of pollinators, promoting more visits to the flowers. Some studies have shown that color and fragrance can be correlated in polymorphic deceptive orchids, but these studies employed color traits based on the human visual system and not the visual perception of pollinators. Thus, we investigated the composition of the floral fragrance of Ionopsis utricularioides (Sw.) Lindl., a polymorphic deceptive orchid, and analyzed possible correlations with the floral color as seen by bees, Apis mellifera L. and Melipona quadrifasciata Lepeletier, using the color hexagon model. We found high color and fragrance intraspecific variation, as expected for deceptive species. However, we found no color-fragrance association in individuals, either by comparing fragrance profiles with the color variable saturation or by comparing them with the placement of individuals in the color hexagon for both bee species. This lack of correlation contradicts the biochemical pathway hypothesis, which proposes that associations between floral color and scent in polymorphic flowers arise from shared biochemical pathways. However, a complete absence of correlation between floral signals is consistent with selection arising through pollinator cognitive ecology. Lack of correlation would increase the floral variability perceived by bees, given their multimodal learning, and this variability could disrupt avoidance learning of deceptive flowers, thus enhancing the efficacy of the plant's deceptive pollination mechanism. (AU)

• FAPESP's process: 19/10620-2 - Turtle macroevolution: contributions from quantitative, virtual paleontology, and biomechanical analyses
• Grantee: Gabriel de Souza Ferreira
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 15/05919-8 - Is floral trait polymorphism related to pollination in deceptive orchids?
• Grantee: João Marcelo Robazzi Bignelli Valente Aguiar
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 14/50871-0 - INCT 2014: National Institute of Science and Technology of Semiochemicals in Agriculture
• Grantee: José Roberto Postali Parra
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 19/20408-0 - The effect of pesticides in learning and memory of native Brazilian bees
• Grantee: João Marcelo Robazzi Bignelli Valente Aguiar
• Support Opportunities: Scholarships in Brazil - Post-Doctoral