Abursanema iranicum

Etymology. The name of the genus is Greek meaning ‘ nematode without a bursa’ and is neuter in gender. Specific epithet refers to the country of occurrence. Molecular phylogenetic relationships. Partial 18 S rDNA phylogeny. Our 942 bp partial SSU rDNA sequence, GenBank accession number KF 885743, was used to determine the phylogenetic relationships of Abursanema n. gen. with other tylenchid nematodes. A BlastN search of the GenBank sequence database was performed and the closest sequences / species, along with sequences of genera with morphological similarity, were selected for inclusion in the analyses. The dataset was composed of 2493 total characters, of which 2118 characters were variable and 1824 characters were parsimony-informative after manual editing. The average nucleotide composition was as follows: 25.7 % A, 20.6 % C, 26.4 % G and 27.2 % T. Figure 3 presents a Bayesian phylogenetic tree inferred from the multiple alignment of partial SSU sequences of 23 tylenchid taxa, one outgroup taxon and one isolate of the newly recovered / sequenced genus. The BPP and ML BS values are given on the appropriate clades in the form BPP / ML BS. In this tree, the new genus forms a clade with one species of Deladenus Thorne, 1941 (saccession number EU 306345), and two species of Sphaerularia (accession numbers AB 300595 and AB 250213), members of the superfamily Sphaerularioidea (see Siddiqi, 2000). The monophyly of this clade is well supported in both BI and ML methods (1.00 and 0.96 % respectively). The other species of Deladenus used in our analyses (D. proximus Bedding, 1974, accession number JF 304744) does not share a common ancestor with Deladenus sp. (EU 306345) and occupies another position in the tree. This clade forms a sister clade to the remaining members of Hexatylina with low BPP (0.55) and no support under ML. Based on the current paucity of data and the restricted number of Hexatylina species that have been sequenced, the relationships among these taxa cannot be clearly resolved. D 2 / D 3 segment of 28 S rDNA phylogeny. To reconstruct the 28 S rDNA tree, a 706 bp partial sequence of D 2 / D 3 region with accession number KF 885742 was used. Figure 4 presents the phylogenetic tree of 37 tylenchid taxa, one outgroup and one isolate of Abursanema iranicum n. gen., n. sp. The dataset was composed of 941 total characters of which 887 characters were variable and 827 characters were parsimony-informative after manual editing, with an average nucleotide composition of 23.7 % A, 19.6 % C, 29.8 % G and 26.9 % T. As in the 18 S tree, the new genus formed a clade with two species of Sphaerularia (AB 300595 and AB 733665) with high BPP and ML BS support. This makes sense, considering the morphological similarities of these taxa, mostly in the shape of the pharynx. According to Siddiqi (2000), the families Sphaerulariidae and Paurodontidae are synonymous and the grouping of Sphaerularia, as a member of Sphaerulariidae, and the new genus, as a member of Paurodontidae, in our tree supports his opinion.