مطالعه مولکولی و ریخت شناختی گونه Aporcelinus mediterraneus

The genus Aporcelinus belonging to the Aporcelaimidae family, is characterized by its ventrally curved strong body with 0.9 to 2.2 mm long, two-layered cuticle of the different thickness, lip region offset by constriction, Lips rounded and more or less distinct, amphideal fovea cup-shaped with broad opening , odontostyle somewhat longer than lip region width with an aperture occupying half of its length, cardia conical with a dorsal gland-like structure present at pharyngo-intestinal junction, genital system of female didelphic-amphidelphic, vulva transverse with sclerotized lips, short pre-rectum, tail conical with convex dorsal contour or at first a convex-conoid and then concave, 1-2.5 times the anal body diameter long, similar in both sexes. In order to study the genera of this family, a number of soil samples were collected from rhizosphere of various plants in East- Azarbaijan province during 2016-2017. Nematodes were extracted using the modified whitehead tray method, fixed by De Grisse method and transferred to anhydrous glycerin. After the preparation of permanent slides, identification of the nematodes was performed based on morphological and morphological characteristics using light microscopy and valid keys. In the molecular study, the genomic region of D2-D3 segment of 28S rRNA, was amplified using specific primers and sent for sequencing. The maximum likelihood phylogenetic methods was used for reconstructing of the phylogenetic tree. The understudy population was identified as Aporcelinus mediterraneus based on morphometric, morphological and molecular data. The comparison of its sequences related to the D2-D3 segment of 28S rRNA gene showed homology with available sequences of this species. This species is most similar to A. diadematus, but is differentiated from this species by having a cylindrical body with less curvature, less distinctive lips and a longer peri-rectum, longer body length (1.70-2 vs 1.40-1.65 mm), lip region (18.7- 20.6 vs. 16-18 μm), larger odontostyle (21.8-23.7 vs 20-21 μm) and longer tail length (59.3 -71.4 vs. 45-55 μm). This species is similar to Allodorylaimus andrassy based on morphometric and morphological characteristics but is distinguished from this species regarding the following indices: L (1.7-2 vs 2.2 mm), lower a (23-27 vs 29-33), lower b (3.3-4.3 vs 5.3-6), lower c (25-32 vs 37-41) and greater V (50-57 vs 47) values. Taking into account the position of A. andrassy and A. mediterraneus in a common clade, it can be with high probability that the first species also belongs to the genus Aporcelinus and its diagnosis requires reconsideration.