Molecular Phylogeny of Nepenthaceae Based on Cladistic Analysis of Plastid trnK Intron Sequence Data

Abstract

Nepenthaceae are an exceptional family with regard to carnivory and the uniformity of characters. This makes it difficult to resolve phylogenetic relationships due to convergent evolution of morphological features. Using comparative sequencing of the chloroplast trnK intron, the monophyly of this complex family and hypotheses of infrageneric relationships were tested. Sequences from 71 Nepenthes taxa, representing all groups and two taxa of the closely related Ancistrocladaceae and Dioncophyllaceae as outgroup, were determined and analysed using maximum parsimony methods. Results of this analysis show that the isolated taxa N. distillatoria (Sri Lanka) and N. pervillei (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 these taxa. N. khasiana (North India) has an intermediate position between these relic Western species and the remaining taxa. The species of the Malay Archipelago can be referred to three distinct lineages which indicate a correlation to biogeography. Thus the recent disjunct distribution of Nepenthes is interpreted as a result of an incisive extinction of progenitors, a process of migration and a subsequent diversification on the islands of Borneo, Sumatra, Sulawesi and New Guinea. Based on our molecular data, two interpretations concerning the origin of Nepenthes are possible: i) evolution in the Northern Tethys which is supported by fossil pollen records from the European Focene, or, ii) a Gondwanaland origin at a time when the Indian plate was separated from Madagascar. Molecular data indicate that colonization of SE Asia started from an ancient Indian stock. Subsequently, in the Malay Archipelago a new secondary centre of diversity developed. Madagascar, the Seychelles and New Caledonia were probably reached by migration via land bridges, starting from widespead common ancestors with subsequent extinction leaving the current taxa. There is no evidence for long‐distance dispersal. Current infragenic classification of Nepenthes is only partly in accordance with the phylogeny inferred from trnK intron data.

Chemical composition of epicuticular wax crystals on the slippery zone in pitchers of five Nepenthes species and hybrids

“…The sequences of N. albomarginata and N. alata were identical to those previously reported for the same species (Gene Bank accession numbers AF315908 and AF315891, respectively, Meimberg et al 2001). The sequence of the N. khasiana specimen (1,800 of 2,400 bp determined) was highly diverging from the published sequence of N. khasiana (Meimberg et al 2001).…”

“…The sequences of N. albomarginata and N. alata were identical to those previously reported for the same species (Gene Bank accession numbers AF315908 and AF315891, respectively, Meimberg et al 2001). The sequence of the N. khasiana specimen (1,800 of 2,400 bp determined) was highly diverging from the published sequence of N. khasiana (Meimberg et al 2001). Instead, the N. "khasiana" specimen investigated here showed no diVerences to the sequences previously published for N. albomarginata and N. raZesiana (AF315908 and AF315910), indicating that it had been hybridized during cultivation.…”

“…The sequence determined for N. x intermedia was most similar to Nepenthes northiana and thus inherited from species other than N. raZesiana or N. hirsuta, the assumed parental species for N. x intermedia. In addition, the sequence diVered by two autapomorphic pointmutations from all other Nepenthes species investigated previously (Meimberg et al 2001(Meimberg et al , 2006. In summary, all Wve specimen were clearly distinct from the previously investigated N. alata, and could be assigned to three groups deWned as (1) the species N. albomarginata, (2) the hybrids of known origin N. x superba and N. x henriana, and (3) the hybrids of unknown origin N. "khasiana" and N. x intermedia.…”

“…and Nepenthes khasiana, as well as of the three culture hybrids Nepenthes x intermedia, Nepenthes x superba, Nepenthes x henriana were continuously cultivated under tropical conditions in greenhouses in the Botanical Garden of the University of Würzburg. To verify the identiWcation of these specimens, plastid trnK introns were sequenced and compared with previously published sequence data (Meimberg et al 2000(Meimberg et al , 2001. DNA isolation, PCR ampliWcation of the trnK intron, sequencing and phylogenetic analysis was performed as described previously (Meimberg et al 2001(Meimberg et al , 2006.…”

Phylogeny and Biogeography of Exacum (Gentianaceae): A Disjunctive Distribution in the Indian Ocean Basin Resulted from Long Distance Dispersal and Extensive Radiation

“…Therefore, Cenozoic dispersal was considered as a more plausible explanation than Mesozoic vicariance. A few similar debates exist in plants; for example, the oceanic dispersal versus Gondwana vicariance for the biogeography of the genus Adansonia (Baum et al, 1998), the circum-global dispersal versus Gondwana vicariance for the history of the family Melastomataceae , migration versus vicariance in Malpighiaceae (Davis et al, 2002a(Davis et al, , 2002b, the post-Gondwana longdistance dispersal versus Gondwana vicariance for the historical biogeography of the genus Polyscias (Plunkett et al, 2001), and the widespread-extinction hypothesis versus vicariance or long-distance dispersal theories for the history of the genus Nepenthes (Meimberg et al, 2001). Recently, Sanmartin and Ronquist (2004) also found that most of the plant patterns of suspected Gondwanan origin fit a dispersal rather than a vicariance scenario.…”