Morphology and molecular study of an entomopathogenic nematode, Steinernema bicornutum (Nematoda, Rhabditida, Steinernematidae) from Iran

An entomopathogenic nematode was isolated by Galleria baiting technique from soil samples collected near Marand, East Azarbaijan province, North-west of Iran during 2003. Based on morphological and morphometric characters, as well as molecular data it was identified as Steinernema bicornutum Tallosi, Peters & Ehlers, 1995. Morphometrics comparison of the isolate with the type species showed no obvious differences between them. Differences in ITS-rDNA PCR-RFLP were found between the Iranian isolate, i.e. IRA7, with the type (Yugoslavian) isolate. The RFLP analysis was able to distinguish Iranian isolate from the type population of S. bicornutum in the HinfI (four restriction sites in the type vs three restriction sites in the IRA7), Hin6I (550, 250 and 250 bp in the studied isolate vs 541 and 474 in the type isolate) and AluI profiles (715, 177 and 123 in the type and 710 and 220 in the IRA7). These molecular differences are considered as intraspecific variations, and the described population from Iran is another isolate of S. bicornutum.