Phylogeny and Character Evolution of the Genus Geum L. (Family Rosaceae) from Iran: Evidence from Analyses of Plastid and Nuclear DNA Sequences

In the present study, molecular phylogeny of the genus Geum L. in Iran, including 5 species (G. kokanicum, G. iranicum G. heterocarpum, G. rivale and G. urbanum) from two subgenera (Orthostylus Fisch & Mey and Geum) were studied using nrDNA ITS and cpDNA rpl32-trnL(UAG)and combined sequence data. Phylogenetic analyses were performed using maximum parsimony approach as implemented in PAUP*, Bayesian method using MrBayes programm and Maximum Likeliood analysis using RaxmlGUI software. The parsimony analysis led to the formation of nrDNA ITS majority-rule consensus tree with a main clade (A), comprising Geum species and its related genera especially Coluria R. Br., Acomastylis Greene, Erythrocoma Greene and Novosieversia F. Bolle., arranged in two monophyletic groups. In all obtained trees, the two representatives of subgenus Geum completely were resolved and formed monophyletic group. While 3 species of the subgenus Orthostylus formed both tritomy (in nrDNA ITS sequence data analysis) and monophyletic group (in cpDNA rpl32-trnL (UAG) and combined sequence dataanalysis). The results of the present study showed that phylogenetic relationship of the genus is strongly under the influence of hybridization and polyploidy (allopolyploidy). The current result support circumscriptions of the genus presented in flora Iranica and flora of Iran. In this study, the evolutionary trends of fruits morphology, exin sculpturing, seed micromorphology and petiole anatomy were evaluated. Key words: