Morphological mutant in the entomopathogenic nematode, Heterorhabditis bacteriophora

Heterorhabditis bacteriophora is an entomopathogenic nematode that has potential as a biological control agent. As a first step in the genetic analysis of this nematode, we induced and isolated a short nematode (dumpy) from the F2 progeny of an EMS mutagenized nematode. Phenotypically, the dumpy adult is 60% shorter than the wild type. There is almost no longitudinal growth after the infective juvenile stage. Dumpy is completely recessive with 100% penetrance and uniform expressivity. When F1 progeny were allowed to self, F2 progeny segregated wild: dumpy in a 15:1 ratio (chi 2 = 0.634, .5 > P > .2). This dumpy mutation (Rhdpy) complements another dumpy mutation isolated in Israel and is the second gene known for this species.