Two orchids, one scent? Floral volatiles of Catasetum cernuum and Gongora bufonia suggest convergent evolution to a unique pollination niche

Autor(es)

Nunes, Carlos E. P. ^[1] ; Gerlach, Guenter ^[2] ; Bandeira, Karen D. O. ^[3] ; Gobbo-Neto, Leonardo ^[3] ; Pansarin, Emerson R. ^[4] ; Sazima, Marlies ^[5]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Inst Biol, Programa Posgrad Biol Vegetal, CP 6109, BR-13083970 Campinas, SP - Brazil

^[2] Bot Garden Munchen Nymphenburg, Menzinger Str 61, D-80638 Munich - Germany

^[3] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, Av Do Cafe S-N, BR-14040903 Ribeirao Preto, SP - Brazil

^[4] Univ Sao Paulo, Fac Filosofia Ciencias & Letras, Dept Biol, BR-14040901 Ribeirao Preto, SP - Brazil

^[5] Univ Estadual Campinas, Inst Biol, Dept Biol Vegetal, CP 6109, BR-13083970 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: FLORA; v. 232, p. 207-216, JUL 2017.
• Citações Web of Science: 8

Resumo

Floral volatile organic compounds (VOCs) are important signals in plant-pollinator communication and thus subjected to olfactory-mediated selection. Occasionally, phylogenetically unrelated plant species will converge towards similar patterns of floral scent signalling to harness pollinators, representing a common adaptive pollination niche. Catasetum cernuum and Gongora bufonia, epiphytic orchids that are native to the Atlantic Forest of southeastern South America, are exclusively pollinated by male Eufriesea violacea orchid-bees; we hypothesised that the two species have converged towards similar floral scent compositions to effectively attract these particular fragrance-seeking floral visitors. The similarity of the chemical composition of floral scent samples obtained through headspace collection was tested using multiple approaches of multivariate analyses (Multiple Response Permutation Procedure-MRPP). According to MRPP, floral scents of C. cernuum and G. bufonia are significantly different. Additionally, the floral scents of C. cernuum and G. bufonia present (E)-beta-ocimene and (E)-epoxyocimene as their major compounds, respectively. (E)-beta-ocimene is a common constituent of floral scents from euglossine-pollinated orchids, while (E)-epoxyocimene is quite rare in orchids' floral scents and it is found in only a few other species which occur outside the distribution range of C. cernuum, G. bufonia and E. violacea. However, 12 out of the 34 identified VOCs, including (E)-beta-ocimeneand (E)-epoxyocimene, are shared between both species. Therefore, we assume that both (E)-beta -ocimeneand (E)-epoxyocimene, either alone or mixed with other floral VOCs, play a major role in the specific association between these two orchids and their exclusive euglossine pollinator. (C) 2016 Elsevier GmbH. All rights reserved. (AU)

• Processo FAPESP: 14/14969-6 - Evolução das características florais em um gênero neotropical exclusivamente polinizado por abelhas Euglossine
• Beneficiário: Emerson Ricardo Pansarin
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 14/20436-0 - Metabolômica como ferramenta na análise quimiotaxonômica do gênero Catasetum (Orchidaceae)
• Beneficiário: Karen Dayane de Oliveira Bandeira
• Modalidade de apoio: Bolsas no Brasil - Mestrado