Phylogenetic Analysis of Medicagoid Trigonella L. Species based on ITS Sequence Data

etc. (Mirzaei et al., 2015b). Recent molecular and morphological evidences indicate the Fabaceae as a monophyletic family. The subtribe Trigonellinae from the tribe Trifoliae of family Fabaceae consists of three genera, Trigonella, Medicago, and Mellilotus that generic delimitation between Trigonella and Medicago has long been a matter of controversy. Members of this subtribe are united by the consistent presence of pinnately trifoliate leaves and high bootstrap support (99%) in analyses of matK (Steel et al., 2003). Some of the earlier taxonomical studies for delimitation of Trigonella and Medicago such as floral characters, asymmetric leaves, phenolic variation, stigma morphology, pollen-ovul pattern and seed characters for discriminating between them were not successful (Bena, 2001) but Small (1987) based on some floral morphological characters transferred 23 Trigonella species including Bucerates and Lunatea sections to the genus Medicago and named them Medicagoid species (Gazara et al., 2001). Medicagoid species are distributed in dry regions and Mediterranean climate in Asia, Europe, North and South America and North Africa (Small, 2011). Molecular markers such as the internal transcribed (ITS) of nuclear ribosomal DNA (rDNA) consists of 18s, ITS1, 5.8 S, ITS2, 28S with several hundred copies in eukaryotes is one of the most extensive sequence markers provides phylogenetic information belonging to wide systematic levels due to amplifying even from small quantities of DNA and has a high degree of variation even between closely related species. The previous molecular studies of Medicagoid species by using analyses of the nrDNA were focused on Medicagoid species by Downie et al. (1998), Bena (2001), Salimpour et al. (2013) and Dangi et al. (2016). These studies proved that majority of Medicagoid species in two sections are monophyletic and are better joined to genus Medicago rather than the genus Trigonella. Major aim of our study was to survey the taxonomic and phylogenetic relationships within Medicagoid species found in Iran. To reach this aim, the internal transcribed species (ITS) region of the 18s-5.8s – 28s nuclear ribosomal DNA (nrDNA) sequenced.