Lobocriconema iranense (Van den Berg, Eskandari, Tiedt & Karegar, 2010) n. comb. and description of L. nokandense n. sp. (Nematoda: Criconematidae) from Iran

Two populations of Lobocriconema were recovered from the rhizosphere of Parrotia persica in Rango forest, Gorgan, and Nargesi forest, Nokandeh, Golestan province, northern Iran. Both of the recovered populations were characterised using morphological (light and scanning electron microscopy), morphometric and molecular data based upon small, partial large and internal transcribed spacer 1 ribosomal RNA (SSU, LSU D2-D3, ITS1 rDNA) and the mitochondrial cytochrome c subunit oxidase I (COI mtDNA) gene sequences. The first examined population, recovered from Gorgan, was mainly characterised by having 34-39 retrorse body annuli 11-16 μm thick at mid-body with crenate, dentate and lobulate margins, longitudinal cuticular scratches on entire body on both lateral regions, sometimes one or two anastomoses along the body, a single labial annulus with smooth margin and smaller than the first body annulus, four distinct submedian lobes, simple open vulva with no overhang, and a terminal anus. This population was almost identical to Neolobocriconema iranense, a close examination of a topotype population recovered in this study confirming that they were conspecific. The second population, L. nokandense n. sp., was recovered from the Nokandeh and looked similar to the first population but was morphologically separated from it by a slightly crenate labial annulus under SEM (vs smooth), longer tail (13-21 vs 6-10 μm) and smaller ratio c (23.6-32.4 vs 44.7-86.0). In molecular phylogenetic analyses, the two populations formed a clade in both SSU and LSU phylogenies. In ITS1 and COI phylogenies, the Nokandeh population (the new species) formed a separate sister clade to the N. iranense clade. Detailed observations using SEM data revealed a small annulus between the submedian lobes and the single labial annulus, an open vulva and a slightly ornamented cuticle in all three studied populations (the newly recovered populations from Golestan and the topotype population of N. iranense from Mazandaran province and the new species), corroborating their placement under Lobocriconema. As a result, N. iranense was transferred to Lobocriconema as L. iranense n. comb. (= N. iranense). The new species was morphologically compared with its close relatives L. iranense n. comb., L. pauperum, L. incrassatum, and L. nasuense, all of which having the aforementioned small annulus between the submedian lobes and the first labial annulus. The phylogeny of the genus is discussed.