rDNA ITS POLYMORPHISM ANALYSIS OF ENTOMOPATHOGENIC NEMATODES

Entomopathogenic nematodes, Steinernema and Heterorhabditis are currently being mass-produced commercially and used to control many economically important pests as an effective biocontrol agent. The biological control potential of these nematodes requires rapid and reliable diagnostic methods for species identification. In this study, rDNA ITS polymorphism of 47 local and introduced entomopathogenic nematode isolates was analyzed by the rDNA ITS PCR-RFLP method, and a phylogenetic tree was constructed from the data obtained. No length variation was observed for ITS regions among the 47 isolates. However, variations in the RFLP patterns were recorded after digestion of the amplified ITS PCR products of various nematode isolates with nine restriction enzymes. Digestion patterns provided strong evidences for the separation of Steinernema and Heterorhabditis spp. From the patterns, the tested Steinernema and Heterorhabditis isolates contained eleven and four groups respectively. The results obtained enlarge the RFLP patterns, which is very useful by other researchers for the identification of entomopathogenic nematodes.