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During a nematological survey in southern Iran, a population belonging to the family Tylenchidae was recovered from a tomato field in Bushehr province. The recovered population belongs to the genus Filenchus, was described and illustrated herein as F. multistriatus n. sp. It is mainly characterized by having a wide and low annulated lip region continuous with adjacent body; amphidial openings confined to the labial plate; four lines in lateral fields forming three bands, with the two outer bands broken by transverse, and the inner one broken by both transverse and longitudinal lines; and median bulb oval with visible valve and elongate-conoid tail uniformly and gradually narrowing toward the distal region, ending in a widely rounded tip. Its morphological and morphometric differences with three closely similar species were discussed. The phylogenetic relationships of the new species with other relevant genera and species were reconstructed using partial sequences of small, and large subunit ribosomal DNA (SSU and LSU rDNA) sequences. Morphometric and morphological data were also provided for an Iranian population of F. sandneri recovered from Bushehr province. Both populations were characterised using SEM data.

Thada populus n. sp. was found in the rhizosphere of Populus euphratica in the city of Dezful, south-western Iran. The new species is characterized by its 365-453 μm body length, cuticle with transverse annuli 0.9-1.2 μm wide, lateral fields with four lines, lip region low with one or two annuli, 7.0-8.5 μm wide at base, longitudinal or slightly sigmoid amphidial slit, delicate stylet 8.4-9.8 μm long with posteriorly directed knobs, dorsal pharyngeal gland opening at 1.0-1.5 μm posterior to the stylet knobs, non-muscular and valve-less median bulb, pyriform and offset basal bulb, almost oval spermatheca, posterior position of vulva (V = 75-79%) without lateral membrane, short post-vulval uterine sac and conical tail with finely to broadly rounded terminus. Morphological differences of the new species with those of the type species, Thada striata, are discussed. Molecular phylogenetic studies of the new species using partial sequences of small subunit ribosomal DNA revealed that the new species formed a clade with Malenchus spp., Filenchus facultativus, F. fungivorus and Filenchus sp. in Bayesian inference. Morphological and molecular phylogenetic studies were also performed on Tenunemellus indicus, the second recovered species, the latter analysis using partial sequences of large subunit ribosomal DNA. In the inferred Bayesian tree, T. indicus formed a clade with Labrys fuzhouensis, Lelenchus leptosoma from the Netherlands, Malenchus spp. and Filenchus discrepans.

Paktylenchus tuberosus gen.n., sp.n. is described and illustrated from soil around Solanum tuberosum from Kaghan Valley, Pakistan. Paktylenchus gen.n, can be distinguished from the most closely related genus, Agelenchus Andrassy, 1954, by the distinct longitudinal striae, three incisures in the lateral field, and absence of males. Paktylenchus tuberosus shows affinities to Coslenchus Siddiqi, 1978 but differs in having an oblique vagina-to-body axis and a prominent sunken vulva with vulval flaps. Four genera of the subfamily Tylenchinae are also discussed herein.