مشخصات پژوهش

Background: The position of Digramma interrupta (Cholodkovsky, 1914) remains disputable as it was raised by Cholodkovsky from Ligula alternans. This study aims to survey evolutionary relationships and the taxonomic position of D. interrupta and L. intestinalis. It also intends to support or reject the validity of D. interruptaas an independent genus and its correlation with Ligula intestinalis on the basis of their morphological characteristics and a study on molecular data. Methods: PCR was used to generate a fragment spanning two independent ITS-inclusive parts: ITS1-5.8S and ITS2 with two pairs of primers. Results: Nucleotide variation between L. intestinalis and D. interrupta samples amounts to about 3% to 7%. Between samples of L. intestinalis in this study and GenBank data, and also between D. interrupta specimens and GenBank data, the diversity was seen for about 1% to 3%. Also, about 1% to 4% nucleotide variation was seen only in L. intestinalis samples caught from the same host, which could be supplementary to the presence of a species and/or strains in this genus. Conclusion: We reach and verify the theory that maybe D. interrupta was just a rare diplogonadic form of the Ligula species not a different genus and not synonymous with the Ligula genus, but only another species of the Ligula genus.