Morphological and molecular characterization of a new isolate of Heterorhabditis bacteriophora Poinar, 1976 from East Azarbaijan, Iran


  • M. Nikdel
  • G. Niknam
  • G. Eliasy


Heterorhabditis bacteriophora, strain Azarbaijan (IRAZ8), was collected from a natural rangeland in East Azarbaijan province, Iran. Morphometric and morphological characters of the new isolate were compared with those published for the type species and of other isolates obtained from various regions of Iran. The results showed that the characteristics of infective juveniles and amphimictic females of IRAZ8 are similar to those of other isolates with some minor differences. However, hermaphroditic females have a peculiar cuticular pattern surrounding the vulva, forming a number of transverse ridges separated by grooves and protruding outward with distinct crescent patterns and hypertrophied vulval lips. In the males, the proximal portion of the gubernaculum is noticeably curved and the eighth pair of bursal papillae is shorter. Molecular studies of the rDNA ITS region showed that the Iranian isolate is closely related to the other described isolates of H. bacteriophora in GenBank and that they form a monophyletic group with a high bootstrap support.