Molecular phylogeny of Nepenthaceae based on cladistic analysis of plastidtrnK intron sequence data

Nepenthaceae are an exceptional family with regard to carnivory and the uni formity of characters. This makes it difficult to resolve phylogenetic rela tionships due to convergent evolution of morphological features. Using comp arative sequencing of the chloroplast trnK intron, the monophyly of this co mplex family and hypotheses of infrageneric relationships were tested. Sequ ences from 71 Nepenthes taxa, representing all groups and two taxa of the c losely related Ancistrocladaceae and Dioncophyllaceae as outgroup, were det ermined and analysed using maximum parsimony methods. Results of this analy sis show that the isolated taxa hi. distillatoria (Sri Lanka) and N. pervil lei (Seychelles) are the most basal, clearly separated from the Madagascan taxa N. madagascariensis and N. masoalensis which are placed in a distinct subclade. This corresponds with some plesiomorphic characters shared by the se taxa. N. khasiana (North India) has an intermediate position between the se relic Western species and the remaining taxa. The species of the Malay A rchipelago can be referred to three distinct lineages which indicate a corr elation to biogeography. Thus the recent disjunct distribution of Nepenthes is interpreted as a result of an incisive extinction of progenitors, a pro cess of migration and ii subsequent diversification on the islands of Borne o, Sumatra, Sulawesi and New Guinea. Based on our molecular data, two inter pretations concerning the origin of Nepenthes are possible: i) evolution in the Northern Tethys which is supported by fossil pollen records from the E uropean Focene, or, ii) a Gondwanaland origin at a time when the Indian pla te was separated from Madagascar. Molecular data indicate that colonization of SE Asia started from an ancient Indian stock. Subsequently, in the Mala y Archipelago a new secondary centre of diversity developed. Madagascar, th e Seychelles and New Caledonia were probably reached by migration via land bridges, starting from widespread common ancestors with subsequent extincti on leaving the current tars. There is no evidence for long-distance dispers al. Current infragenic classification of Nepenthes is only partly in accord ance with the phylogeny inferred from trnK intron data.