Rotylenchus sardashtensis n. sp., a monosexual species from Iran, with molecular identification and detailed morphological observations on an Iranian population of Rotylenchus cypriensis Antoniou, 1980 (Nematoda: Rhabditida: Hoplolaimidae).

Rotylenchus sardashtensis n. sp., a new monosexual species is described and illustrated based on morphological, morphometric and molecular studies. Rotylenchus sardashtensis n. sp. appears close morphologically and molecularly to eight known species of the genus, i.e. R. buxophilus Golden, 1956, R. eximius Siddiqi, 1964, R. breviglans Sher, 1965, R. cypriensis Antoniou, 1980, R. pakistanensis Maqbool & Shahina, 1986, R. vitis Cantalapiedra-Navarrete, Liébanas, Archidona-Yuste, Palomares-Rius & Castillo, 2012, R. paravitis Cantalapiedra-Navarrete, Navas-Cortés, Liébanas, Vovlas, Subbotin, Palomares-Rius & Castillo, 2013 and R. dalikhaniensis Aliramaji, Pourjam, Álvarez-Ortega, Pedram & Atighi, 2015 from which the morphological differences are discussed. The new species is characterised mainly in having a hemispherical and well set off lip region with 3-4 annuli under light microscopy and irregular cob-like appearance under scanning electron microscopy (SEM), a stylet 26-30 µm long, a vulva located at 61-77% of body length with double epiptygma, rounded tail with 2-4 annuli and ventral mucron at its tip. Morphologically, R. sardashtensis n. sp. could be distinguished from all similar species within the genus by its matrix code as follows: A3, B1, C1, D4, E1, F2, G2, H5, I2, J2, K1. Rotylenchus cypriensis collected from the rhizosphere of Prunus sp. in Gilangharb region is characterised with its morphological and molecular data. Phylogenetic analyses based on sequences of the D2-D3 expansion region of the 28S rRNA gene and the ITS1 fragment revealed the relationships of both species examined in present study and other species of the genus Rotylenchus Filipjev, 1936 and the family Hoplolaimidae Filipjev, 1934 included in analyses.