Molecular characterizations of the entomopathogenic nematodes, Heterorhabditis bacteriophora and Oscheius myriophilus from Iraq

Abstract

A survey was conducted in three main regions of Iraq to isolate and identify entomopathogenic and insect parasitic nematodes. Soil samples were collected from 15 sites across 3 provinces from grassland, date palm, and citrus fields, and tested for the presence of nematodes. Out of 100 samples collected, 2 isolates of nematodes were recognized. The collected specimens were characterized first morphologically and then by molecular studies to characterize and identify the isolates based on ITS and 18S rDNA genes. Both isolates were recovered from soil samples of citrus and palm orchards located in 3 regions in the city of Baghdad. The isolates were identified by analyzing sequenced results and then by DNA sequences that were blasted against the NCBI database in GenBank. The 2 isolates were separated into 2 genera, assigned as IRQ.1 and were identified as Heterorhabditis and IRQ.2, that was identified as Oscheius. Molecular analysis and phylogenetic relationship of both genera were analyzed, using the DNA sequences of 2 loci. The Heterorhabditis species was assigned as Heterorhabditis bacteriophora, while the Oscheius species was identified as Oscheius myriophilus. These species were the first to be reported in Iraq.