Phylogenetics of Papaver and related genera based on DNA sequences from ITS nuclear ribosomal DNA and plastid trnL intron and trnL-F intergenic spacers.
OBJECTIVE
Representatives from Papaver, Roemeria, Stylomecon and Meconopsis were studied to elucidate phylogenetic relationships between Papaver and these closely allied genera.


METHODS
Two molecular data sets were used individually and combined and included sequences from the internally transcribed spacer region (ITS) of 18S-26S nuclear ribosomal DNA and the trnL intron and the trnL-trnF intergenic spacer region of plastid DNA.


RESULTS
Parsimony analysis demonstrated that the genus is not monophyletic unless the closely related Roemeria, Stylomecon and Meconopsis cambrica are included in a revised circumscription of Papaver. Three distinct clades are resolved in a combined ITS and trnL-F analysis. Clade 1 consists of Papaver sect. Meconella and Asian Meconopsis. Clade 2 contains a group here identified as Papaver s.s., comprising sections Carinatae, Meconidium, Oxytona, Papaver, Pilosa, Pseudopilosa and Rhoeadium. Clade 3 consists of Papaver sect. Argemonidium and Roemeria refracta. A number of diagnostic indels support these groupings. Within clade 2, sects. Papaver and Rhoeadium are either not monophyletic or lack evidence supporting their monophyly.


CONCLUSIONS
The results of this molecular analysis indicate that a number of morphological characters such as valvate capsule dehiscence, dark or light filaments and sessile stigmatic discs have arisen in parallel. The phylogenetic trees are incongruent with the existing taxonomy of Papaver, and a revised classification is suggested.
Carolan
James C
JC
Department of Botany, School of Natural Sciences, University of Dublin, Trinity College, Ireland. james.carolan@ucd.ie
Hook
Ingrid L I
IL
Chase
Mark W
MW
Kadereit
Joachim W
JW
Hodkinson
Trevor R
TR