Phylogeny of holoparasitic Orobanche (Orobanchaceae) inferred from nuclear ITS sequences.
Orobanche is the largest genus among the holoparasitic members of Orobanchaceae. We present the first molecular phylogenetic analysis (using nuclear ITS sequences) that includes members of all sections of Orobanche, Gymnocaulis, Myzorrhiza, Trionychon, and Orobanche. Orobanche is not monophyletic, but falls into two lineages: (1) the Orobanche group comprises Orobanche sect. Orobanche and the small Near Asian genus Diphelypaea and is characterized by a chromosome base number of x=19 and (2) the Phelipanche group contains Orobanche sects. Gymnocaulis, Myzorrhiza, and Trionychon and possesses a chromosome base number of x=12. The relationships between these two groups and to other genera such as Boschniakia or Cistanche remain unresolved. Within the Orobanche group, Orobanche macrolepis and Orobanche anatolica (including Orobanche colorata) constitute two phylogenetically distinct lineages. Intrasectional structurings proposed by some authors for O. sect. Orobanche are not confirmed by the molecular data. In most cases, intraspecific sequence divergence between accessions, if present, is negligible and not correlated with morphological or ecological traits. In a few cases, however, there is evidence for the presence of cryptic taxa.
Schneeweiss
Gerald M
GM
Department of Higher Plant Systematics and Evolution, Institute of Botany, University of Vienna, Rennweg 14, A-1030 Vienna, Austria.
Colwell
Alison
A
Park
Jeong-Mi
JM
Jang
Chang-Gee
CG
Stuessy
Tod F
TF
D005075:Biological Evolution; D002467:Cell Nucleus / Q000235:genetics*; D021901:DNA, Intergenic; D017343:Genes, Plant; D031672:Orobanche / Q000235:genetics*; D010802:Phylogeny; D013045:Species Specificity
D021901:DNA, Intergenic