The floral scents of Nymphaea subg. Hydrocallis (Nymphaeaceae), the New World night-blooming water lilies, and their relation with putative pollinators Artur Campos Dália Maia a,⇑ , Carla Teixeira de Lima b , Daniela Maria do Amaral Ferraz Navarro a , Marion Chartier c , Ana Maria Giulietti b , Isabel Cristina Machado d a Departamento de Química Fundamental, Universidade Federal de Pernambuco, Recife 50740-560, Brazil b Programa de Pós-graduação em Botânica, Departamento de Ciências Biológicas, Universidade Estadual de Feira de Santana, Feira de Santana 44031-460, Brazil c Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14 A-1030, Vienna, Austria d Departamento de Botânica, Universidade Federal de Pernambuco, Recife 50372-970, Brazil article info Article history: Received 25 September 2013 Received in revised form 31 January 2014 Available online 7 May 2014 Keywords: Water lily Nymphaea subg. Hydrocallis Nymphaeaceae Volatile organic compounds (VOCs) Neotropics Nocturnal anthesis Cantharophily abstract Night-blooming water lilies are characterized by intense emission of floral VOCs. Their unique scent-ori- ented pollinators, cyclocephaline scarabs (Scarabaeidae, Cyclocephalini), are attracted to flowers that they use as reliable sources of food and as mating aggregation sites. Chemical analysis of floral scent sam- ples of seven species of Nymphaea subg. Hydrocallis established remarkably simple fragrant blends, each of which was dominated by one or two prominent compounds that alone accounted for over 95% of total scent emission. A total of 22 VOCs were identified: aliphatics (9), C5-branched chain compounds (5) and aromatics (8). Anisole was the dominant constituent in the floral scents of Nymphaea amazonum subsp. amazonum, N. amazonum subsp. pedersenii and N. tenerinervia, whereas (methoxymethyl)benzene was the most abundant VOC in samples of N. lasiophylla and N. lingulata. Flowers of N. rudgeana and N. gard- neriana emitted high amounts of methyl hexanoate and methyl 2-methylbutanoate. Comparisons of floral VOC composition including other day- and night-blooming species of Nymphaea and Victoria obtained from the literature evidenced disparities related to habitus. While flowers of day-blooming species mostly emit aromatic alcohols and ethers, nocturnal species are particularly rich in aromatic ethers, ali- phatic esters and C5-branched chain esters. These findings strongly suggest that the floral scent compo- sition within closely related Nymphaea and Victoria is linked to pollinator selection, and the putative role of floral VOCs in pollinator attractiveness is discussed. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction The genus Nymphaea is the most speciose of the water lily family (Nymphaeaceae). It constitutes a cosmopolite group of perennial aquatic herbs, comprising 45–50 species distributed in five subgenera: Nymphaea subg. Anecphya (7–10 spp.), N. subg. Brachyceras (14–16 spp.), N. subg. Hydrocallis (14 spp.), N. subg. Lotos (2–3 spp.), and N. subg. Nymphaea (8 spp.; Borsch et al., 2011). The monophyly of the subgenera of Nymphaea has convincing molecular phylogenetic support (Borsch et al., 2007, 2011), which also indicates a strong bias in their biogeographical distribution (Löhne et al., 2008). Nymphaea subg. Nymphaea is found through- out the Northern Hemisphere in temperate regions; N. subg. Brachyceras has a Pantropical range, and N. subg. Anecphya is restricted to Oceania (Löhne et al., 2008). Species belonging to these three subgenera are day-blooming and usually characterized by brightly colored flowers that are sought as a pollen and nectar source by unspecialized anthophilous insects, mainly generalist bees and flies (Prance and Anderson, 1976; Schneider and Chaney, 1981). Two vicariant lineages with night-blooming species, N. subg. Lotos and N. subg. Hydrocallis, appear in the Paleo- and Neotropics, respectively (Löhne et al., 2008; Wiersema, 1987). They are associated with a highly specialized and diverse group of nocturnal pollinators, the scarab beetles of the tribe Cyclocephalini (Coleoptera, Scarabaeidae) (Ervik and Knudsen, 2003; Hirthe and http://dx.doi.org/10.1016/j.phytochem.2014.04.007 0031-9422/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Address: Universidade Federal de Pernambuco, Centro de Ciências Exatas e da Natureza, Departamento de Química Fundamental, Av. Jornalista Anibal Fernandes, s/n, Cidade Universitária, Recife 50740-560, PE, Brazil. Tel./fax: +55 81 21267468. E-mail address: artur_campos_maia@yahoo.com.br (A.C.D. Maia). Phytochemistry 103 (2014) 67–75 Contents lists available at ScienceDirect Phytochemistry journal homepage: www.elsevier.com/locate/phytochem