Orchidaceae - 18S

Data: Aligned 18S rDNA sequences for 26 genera of Orchidaceae and appropriate outgroup taxa. Gaps are indicated with "-". Characters 1-50 and 1786-1836 were excluded from the analysis. The alignment was created with the software program Clustal V. Multiple alignment parameters were set with a floating gap penalty of 10 (scale of 1-100; higher value results in shorter gaps) and a fixed gap penalty of 10 (scale 1-100; higher value results in fewer gaps). Taxon name abbreviations in the matrix correspond to the following species and their associated GenBank accession numbers:

Apostasia stylidioides Reichb.f. AF135207; Neuweidia veratrifolia Blume AF135208; Paphiopedilum delenatii Guillaumin AF135206; Cypripedium calceolus L. AFO69208; Tropidia sp. AF135192; Spiranthes cernua (L.) Richards AF135195; Diuris sulphurea R. Br. AF135196; Rhizanthella gardnerii R. Rogers AF135197; Orchis quadripunctata Cyrillo ex. Tenore AF135194; Cephalanthera austinae (A. Gray) Heller(= Eburuphyton austinae) U59949; Neottia nidus-avis Richards U59948; Triphora trianthophora (Swartz) Rydb. AF135193; Cyrtosia septetrionalis (Reichb.f.) Garay AF135198; Erythrorchis cassythoides (A. Cunn. ex Lindl.) Garay AF135199; Epistephium subrepens Hoehne AF135200; Eriaxis rigida Reichb.f. AF135201; Lecanorchis multiflora J. J. Sm. AF135203; Vanilla aphylla Bl. AF135202; Aplectrum hymale Torr. U59937; Corallorhiza maculata (Raf.) Raf. U59940; Cleistes divaricata (L.) Ames AF135205; Isotria verticillata (Muhl. ex Willd.) Raf. AF135204; Hypoxis leptocarpa (Engelm. & A. Gray) Small AF135209; Gladiolus buckerveldii (L. Bol.) Goldblatt L54062; Isophysis tasmanica T. Moore L54063; Chlorophytum nepalense Baker CNU42066

Matrix type: Aligned, interleaved nexus format.

Reference: Cameron, K. M. and M. W. Chase, in press. Nuclear 18S rDNA sequences of Orchidaceae confirm the subfamilial status and circumscription of Vanilloideae. D. Morrison and K. Wilson (eds.), Proceedings of the Monocots II Conference. CSIRO Publishing, Syndey.

Summary of results: 18S rDNA sequences were analyzed from genera representing each subfamily of Orchidaceae. Results support the division of Orchidaceae into at least five subfamilial clades corresponding to Apostasioideae, Cypripedioideae, Vanilloideae, Orchidoideae, and Epidendroideae. The 18S results support the inclusion of Cyrtosia and Lechanorchis within the vanilloid clade and the removal of Rhizanthella from it to a position in the orchidoid clade. Plastid sequences from many of these myco-heterotrophic taxa have been unobtainable. The vanilloid orchids would be classified best as a subfamily, Vanilloideae, circumscribed to include taxa from previously recognized subtribes Pogoniinae, Vanillinae, Galeolinae, and Lechanorchidinae.

Contact person: Kenneth M. Cameron, The Lewis B. and Dorothy Cullman Program for Molecular Systematics Studies, The New York Botanical Garden, Bronx, NY, 10458, U.S.A., telephone: (718) 817-8182, fax: (718) 817-8166, e-mail: kcameron@nybg.org

Date posted on WWW: 04/16/99

View the data file: (click here)

Download data file: File size 63,306 bytes (click here)