First Record of Three Known Species of the Family Tylenchidae Örley, ۱۸۸۰ (Nematoda: Tylenchina) from Iran with New Morphological and Molecular Data

Three species belonging to three genera of the family Tylenchidae, namely, Cephalenchus leptus, Eutylenchus excretorius, and Lelenchus leptosoma were discovered as first reports for Iran's nematode fauna. They were characterized by morphological, morphometric and molecular phylogenetic studies. The two latter genera are new for Iran. Iranian population of Cephalenchus leptus is characterized by lateral field with six lines in females, stylet length of ۱۶-۲۰ µm and tail length of ۱۵۳-۲۹۰ µm with pointed tip. The recovered population of Eutylenchus excretorius is characterized by ۸۴۸-۱,۰۳۸ µm long females’ body, stylet length of ۲۰.۰-۲۱.۵ µm, having advulval flaps and absence of male. The Iranian population of Lelenchus leptosoma is defined by its narrow slender body, flattened lip region, sinuous amphidial opening and absence of lateral field. The phylogenetic relationships of the three recovered species were studied using the partial sequences of ۲۸S rDNA D۲/D۳ segment and revealed the genera Cephalenchus and Eutylenchus forming a monophyletic clade, while, Lelenchus was placed inside the clade of currently sequenced species of Malenchus in Bayesian tree.