Molecular identification of Verbascum thapsus l. (Ban Tambaaku) and its ITS sequence comparison with other Verbascum l. species

Internal transcribed spacers (ITS) have been widely used for molecular identification of plant species. Present work provides a rapid and accurate approach for the detection and identification of Verbascum thapsus based on ITS sequences. Amplified sequence of 689 bp fragment by ITS1 and ITS4 primers from nrDNA revealed five regions viz. 18S rRNA (partial sequence, >1….64), ITS-1 (>65….240), 5.8S (>241….404), ITS-2 (>405….619) and 28S rRNA (partial sequence >620….689). The ITS sequences (ITS-1, 5.8 and ITS-2) of V. thapsus show 18 species specific informative sites at 108, 115, 125, 126, 130, 153, 174, 215, 216, 229, 242, 517, 543, 580, 581, 582, 583 and 595 that could be used to differentiate V. thapsus species from other species as well as authenticate the species. A comparative phylogenetic analysis of ITS sequence with other Verbascum L. species revealed that V. thapsus and V. nigrum were closely related and clustered together in the phylogenetic tree.