GENETIC DIVERSITY IN INSECT-PARASITIC NEMATODES (RHABDITIDA, HETERORHABDITIDAE)

Little is known about the genetic structure of various species and pop ulations of entomopathogenic nematodes. We determined genetic variabil ity within and among isolates of seven Heterorhabditis species using r andom amplified polymorphic DNA (RAPD) markers. We used 10 random prim ers which were previously identified as useful to quantify genetic var iability among these species. Mean percentage similarity among the ind ividuals of conspecific species was 96.25%, whereas, the mean value am ong different isolates for three species was 83.8%. Mean percentage si milarity among different species was 31.3%. The banding patterns produ ced by RAPDs positively correlated with described morphological classi fication; however, H. hawaiiensis could not be separated from H. indic us, or H. marelatus from H. hepialius. RAPD profiles placed an unident ified isolate (IS5) with H. indicus. (C) 1998 Academic Press.