Utility of ITS2 sequence data of nuclear ribosomal DNA: Molecular evolution and phylogenetic reconstruction of Lathyrus spp.

• Nuclear ribosomal DNA sequencing among Lathyrus spp.
• ITS intergenic spacer polymorphism.
• Phylogenetic relationships assessed with haplotypic and nucleotide diversity tests.
• ITS2 considered as a barcode.
• The novel overlapping of sections which disagrees with other Lathyrus classifications

The genus Lathyrus comprises about 187 species belonging to thirteen sections and constitutes significant farming weeds and model organisms for genetic and ecological approach. In this work, sequence results achieved from nrDNA-ITS2 (nuclear ribosomal DNA-Internal Transcribed Spacer 2) frame was considered for phylogenetic inter-relationships of 28 Lathyrus species. The final aligned data matrix of ITS2 region yielded 217 characters out of which 109 conserved sites and 104 display nucleotide divergence. The phylogenetic tree resulting from MP analysis exhibited a continuum of genetic variation among Lathyrus species. The ambiguous systematic of Lathyrus is compared with a morphological classification of Kupicha. The ITS2 was efficient for the phylogeny of this genus but it does not agree at 100% with Kupicha’s. This study validates the utility of ITS2-nrDNA not as a part of ITS but as DNA barcode and can serve as a supplementary methodology for identification of broader range of plant taxa.