GENETIC DIVERSITY IN WILD AND LABORATORY POPULATIONS OF HETERORHABDITIS-BACTERIOPHORA AS DETERMINED BY RAPD-PCR ANALYSIS

Genetic variation in laboratory reared biocontrol agents may be reduce d due to founder effect, inbreeding, and selection. We used random amp lified polymorphic DNA (RAPD-PCR) to compare genetic variation in two strains of Heterorhabditis bacteriophora. One strain (IS5) was recentl y isolated from the field and the other strain (HP88) has been reared under laboratory conditions for over 10 years. For each strain, fiftee n inbred lines were generated by eight cycles of selfing of a single h ermaphrodite (reaching > 90 % homozygosity). Genomic DNA from each of the inbred lines was screened with fourteen decamer primers. Genetic v ariation was calculated based on average percentage similarity of DNA banding patterns and cluster analysis. The level of within population variation detected did not differ significantly between the two strain s.