Phylogeny and biogeography of Morinaceae (Dipsacales) based on nuclear and chloroplast DNA sequences

AbstractThe Morinaceae (Dipsacales) contains 13 species placed in Acanthocalyx, Cryptothladia or Morina, and is distributed from the mountains of southeastern Europe through the Himalayas to the Qinghai-Tibetan Plateau, mainly in alpine habitats. Sequence data from two chloroplast regions (the trnK intron and the trnL-F region) and the internal transcribed spacer (ITS) region of nuclear ribosomal DNA were used to infer phylogenetic relationships of Morinaceae and related Dipsacales. Both the nuclear and chloroplast datasets, as well as the combined data, provide strong support for relationships within the Valerina clade, placing Morinaceae as the sister group of a clade containing Valerianaceae and Dipsacaceae plus Triplostegia. The Morinaceae, Acanthocalyx, Cryptothladia, and a clade containing Morina and Cryptothladia, are all supported as monophyletic. However, Morina was found to be paraphyletic in several of our analyses, with Morina longifolia more closely related to Cryptothladia than to other Morina species. There is some evidence that Morina longifolia produces cleistogamous flowers, as do Cryptothladia species. Dispersal-vicariance analyses support the view that Valerina radiated initially within Asia, with subsequent movement into Europe in Morinaceae, Dipsacaceae, and Valerianaceae, and into the New World in Valerianaceae. For Morinaceae, as for a number of plant groups, the Brahmaputra river drainage marks a significant biogeographic divide, although this has been spanned within Acanthocalyx and the Morina-Cryptothladia lineage