| Title: | Pollination of the strongly scented Sarcoglottis acaulis (Orchidaceae) by male orchid bees: nectar as resource instead of perfume |
| Author(s): | Albuquerque NSL; Milet-Pinheiro P; Cruz DD; Navarro D; Machado IC; |
| Address: | "Departamento de Botanica, Programa de Pos-Graduacao em Biologia Vegetal, Universidade Federal de Pernambuco, Pernambuco, Brazil. Laboratorio de Ecologia, Universidade de Pernambuco, Campus Petrolina, Petrolina, Brazil. Departamento de Sistematica e Ecologia, Universidade Federal da Paraiba, Paraiba, Brazil. Departamento de Quimica Fundamental, Universidade Federal de Pernambuco, Recife, Brazil" |
| ISSN/ISBN: | 1438-8677 (Electronic) 1435-8603 (Linking) |
| Abstract: | "The Neotropical orchid genus Sarcoglottis comprises ~40 species, which emit strong floral scents, presumably involved in pollinator attraction. Information on basic aspects of its natural history is scant, with the few studies available so far pointing to nectar-seeking orchid bees as pollinators. Here, we investigated the reproductive biology of Sarcoglottis acaulis, addressing the ecological meaning of its floral scent. In Atlantic Forest fragments of NE Brazil, we described the floral biology, determined the breeding system and recorded the pollinators of S. acaulis. Additionally, we chemically characterized its floral scent and assessed its role on pollinator attraction. Although self-compatible, S. acaulis depends on pollinators to boost fruit set. Male orchid bees of Eulaema atleticana and E. niveofasciata were the only recorded pollinators. They foraged for nectar only, in spite of the strong scent emitted by S. acaulis flowers. The floral scent is composed of six compounds, of which geraniol and nerol elicited electroantennographic responses in Eulaema bees. A synthetic mixture of these compounds attracted Eulaema bees in field assays but did not trigger the stereotyped scent-gathering behaviour. The floral scent of S. acaulis acts in signalling and nectar is the sole reward for pollinators. Despite the low pollinator frequency, S. acaulis shows a high fruit set (77%), particularly when compared to other orchids. Attributes such as pollinia that release small pollen loads, allowing a single pollinia-carrying bee to pollinate several flowers, low amount of nectar, steady-state flowering and traplining behaviour of pollinators, might act together to assure this outstanding fruit set" |
| Keywords: | Animals Bees Flowers *Orchidaceae *Perfume Plant Breeding Plant Nectar Pollination Eulaema euglossine bees floral scents nectar; |
| Notes: | "MedlineAlbuquerque, N S L Milet-Pinheiro, P Cruz, D D Navarro, D M A F Machado, I C eng 310508/2019-3 to ICM/Conselho Nacional de Desenvolvimento Cientifico e Tecnologico/ Proc.n. 311021/2014 to ICM/Conselho Nacional de Desenvolvimento Cientifico e Tecnologico/ Financing Code 001/Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior/ APQ-0320-2.05/17/Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco/ BCT-0288-2.05/17/Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco/ England 2021/06/26 Plant Biol (Stuttg). 2021 Sep; 23(5):719-727. doi: 10.1111/plb.13297. Epub 2021 Jun 25" |
