Molecular phylogeny of Phalaenopsis Blume (Orchidaceae) on the basis of plastid and nuclear DNA

• DOI: 10.1007/s00606-010-0314-1
• Publication Date: 2010-07-03T12:08:33Z
• Authors: C. C. Tsai; Y. C. Chiang; S. C. Huang; C. H. Chen; C. H. Chou
• Keywords: 0303 health sciences; 03 medical and health sciences; 15. Life on land

The internal transcribed spacers (ITS) of nuclear ribosomal DNA (nrDNA) and plastid DNA, including the trnL intron, the trnL-F spacer, and the atpB-rbcL spacer, from most of the living species in the genus Phalaenopsis were sequenced. The monophyly of the genus described by Christenson (Christenson EA (2001) Phalaenopsis. Timber Press, Portland, p 330), that Doritis and Kingidium are synonyms of Phalaenopsis, was supported by these molecular data. Within the genus, subgenus Polychilos was monophyletic, and the species were divided into two subclades. The subgenus Phalaenopsis was shown to be non-monophyletic, because the sections Esmeralda and Deliciosae appeared separated the from sections Phalaenopsis and Stauroglottis. Meanwhile, subgenera Aphyllae and Parishianae were also shown to be non-monophyletic on the basis of the molecular data. Furthermore, the monotypic species of subgenus Proboscidioides, P. lowii, formed a clade with subgenus Aphyllae. In accordance with geographical distribution, the historical geography of Southeast Asia due to the periodic glacial epochs, and molecular phylogeny, two evolutionary trends of Phalaenopsis from the original center in South China to the Philippines, Indonesia, and Malaysia were suggested. First, using Indochina and some older parts of the Philippines (e.g., Mindoro and Palawan) as stepping stones, Phalaenopsis species dispersed from South China to the Philippines, where the sections Phalaenopsis and Stauroglottis of subgenus Phalaenopsis developed. Second, using the Malay Peninsula as a stepping stone, Phalaenopsis species dispersed from South China to Indonesia and Malaysia, where the subgenus Polychilos developed.