Development of heat and desiccation tolerance of genetically selectedhybrid strains of Heterorhabditis bacteriophora during in vivoand in vitro propagation with and without selection pressure

Abstract: Repeated culturing of entomopathogenic nematodes under laboratory or industrialscale can lead to deterioration of beneficial traits. Assessment of the development of heat anddesiccation tolerance was performed on heat and desiccation tolerant hybrid strains ofHeterorhabditis bacteriophora. The test was done in in vivo and in vitro production with orwithout selection pressure for heat and desiccation. Tolerance to heat and desiccation stress wasusually lower when nematodes were propagated without selection pressure but were morepronounced when nematodes had been propagated in vivo compared to in vitro cultivation.