This study is a continuation of our work on other subtribes of the tribe Maxillarieae, especially subtribes Oncidiinae, Stanhopeinae, and Zygopetalinae.
PHYLOGENETICS OF ZYGOPETALINAE
Subtribe Zygopetalinae: ABSTRACT: The phylogenetic relationships of the orchid subtribe Zygopetalinae were evaluated using parsimony analyses of combined DNA sequence data of nuclear ITS 1 and 2 (including the 5.8s region and portions of the flanking 18s and 26s regions) and of the plastid trnL intron plus the trnL-F intergenic spacer and the plastid matK. Analyses of the three separate data sets produced highly congruent and moderately supported patterns, so these were combined in a single analysis. Combined analysis of 104 ingroup and two outgroup taxa produced highly resolved cladograms. Zygopetalinae comprises a Zygopetalum grade or clade (pseudobulbs prominent; leaves usually plicate, revolute); a Huntleya grade (pseudobulbs reduced or lacking; leaves conduplicate), including Dichaea, Huntleya, Chaubardia, and the Chondrorhyncha complex, plus Cryptarrhena that is weakly supported as sister to the Huntleya clade; and a Warrea grade. Chondrorhyncha s.l. is polyphyletic and six genera are proposed as monophyletic segregates.
Details of relationships in the Huntleya alliance based on ITS/matK/trnL-F. See Whitten et al. 2005 for discussion of this group.
Values above branches are Fitch lengths; values below branches are bootstrap percentages followed by Bayesian posterior probability values if > 95; an asterisk indicates posterior probability value <95. Black squares indicate nodes that collapse in the strict consensus tree.
Details of relationships in the Zygopetalum alliance based on ITS/matK/trnL-F. See Whitten et al. 2005 for discussion of this group.
The following reference contains the complete discussion of this group.
Whitten, W.M., N. H. Williams, R. L. Dressler, G. Gerlach, and F. Pupulin. 2005. Generic relationships of Zygopetalinae (Orchidaceae: Cymbidieae): combined molecular evidence. Lankesteriana 5: 87-108.