Preliminary molecular phylogeny of Eurasian Scrophularia (Scrophulariaceae) based on DNA sequence data from trnS-trnG and ITS regions

Abstract

Both nuclear ribosomal internal transcribed spacer (ITS) and chloroplast intergenic trnS-trnG regions of 20 Scrophularia species were isolated and sequenced. Phylogenetic analyses of these data (separately or combined) showed that the most widely distributed Eurasian representative of the genus, Scrophularia umbrosa, was the first-diverging clade within Scrophularia and formed sister species to all Asian species in the analysis. The Irano-Turanian representatives of the genus were shown to group with each other, with the two Sahara-Arabian representatives of Scrophularia grouping together and nested deeply inside. Our molecular evidence did not support taxonomic recognition of Grau's (Grau J. 1981b. Scrophularia. In: Rechinger KH, editor. Flora Iranica. Graz, Austria: Akademische Druck- u. Verlagsanstatl. Vol. 147, pp. 213–284.) informal species groups. Parallel and independent evolutions were inferred for some morphological characters that were previously used as diagnostic criteria. On the contrary, occurrence of a foliate inflorescence could be used to recognize the subclade within the genus.

Keywords:

• ITS
• morphological data
• phylogeny
• Scrophularia
• trnS-trnG

Acknowledgments

We are very much indebted to Dr. Shahin Zarre from the University of Tehran for his considerable help with the experiment and the data analysis. Grants from the University of Tehran Research Council to Faride Attar are gratefully acknowledged.