Deceptive strategy in Dactylorhiza orchids: multidirectional evolution of floral chemistry

• DOI: 10.1093/aob/mcz003
• Publication Date: 2019-01-03T15:11:19Z
• Authors: Ada Wróblewska; Lech Szczepaniak; Andrzej Bajguz; Iwona Jędrzejczyk; Izabela Tałałaj; Beata Ostrowiecka; Emilia Brzosko; Edyta Jermakowicz; Paweł Mirski
• Keywords: Orchidaceae

The deception strategies of orchids remain poorly understood, especially in regard to the chemical compounds emitted from their flowers and interaction with various taxonomic groups pollinators. We investigated phylogenetic relationships compared variation floral between food-deceptive Dactylorhiza taxa (D. incarnata var. D. ochroleuca, fuchsii majalis) populations north-eastern Poland. propose a model evolution based on signals this genus. A Bayesian approach polymorphic plastid DNA (trnL, trnF psbC–trnK), internal transcribed spacer (ITS) sequences flow cytometry data was applied confirm status studied orchids. also identified classified pollinators flower visitors each population level our results literature data. composition pentane diethyl ether extracts analysed by gas chromatography–mass spectrometry. Variation components visualized non-metric multidimensional scaling Bray–Curtis dissimilarity. genetic distinctiveness incarnata, majalis confirmed. No hybrids them were found, but chloroplast (cpDNA), ITS haplotypes showed similarity ochroleuca. determined that Apis mellifera (Hymenoptera) only shared pollinator these taxa. Strangalia attenuata Alosterna tabacicolor (Coleoptera) Volucella pellucens V. bombylans observed pollinating fuchsii. Visualization emission rates 61 detected (mainly hydrocarbons aldehydes) 51 (with abundant benzenoids non-aromatic acids) strongly differentiated majalis, while those two varieties (var. ochroleuca) almost identical. While clearly supported distinct lineages patterns more complex within series (alkanes taxon-specific (benzenoids esters). Their bouquet can influence sexual, social feeding behaviour different ways. attracted both species-specific Dactylorhiza, confirming multidirectional character Reduction pollination levels orchid may promote hybridization them.