Molecular Markers Reject Monophyly of the Subgenera of Satyrium (Orchidaceae)

Satyrium is a morphologically anomalous genus. Although clearly a member of the terrestrial orchid subfamily Orchidoideae, its phylogenetic relationships within the subfamily are uncertain. Morphologically it has always been placed in tribe Diseae, albeit associated with different subtribes, but recent molecular studies suggest a closer relationship to Orchideae. The infrageneric classification of Satyrium is equally problematic, and several different classifications are available. The only infrageneric classification based on a phylogenetic analysis of morphological characters resulted in recognition of the three subgenera Brachysaccium, Bifidum, and Satyrium. DNA sequence data from nuclear (ITS1, 5.8S, and ITS2) and plastid (trnL intron, trnL-F intergenic spacer, and part of the matK gene and trnK intron) genome are used to test the monophyly of these subgenera. Topologies of cladograms resulting from parsimony analysis of separate datasets show several cases of incongruence, some of which are well supported. Combined analysis is performed on a dataset from which two problematic taxa are pruned. Parametric bootstrap, as well as Bayesian posterior probability, rejects monophyly of all three subgenera and alternative groupings are suggested.