Submitted to: Society for Invertebrate Pathology Annual Meeting Proceedings
Publication Type: Abstract only
Publication Acceptance Date: 8/1/2004
Publication Date: 8/1/2004
Citation: Bai, C., Shapiro Ilan, D.I., Gaugler, R., Hopper, K.R. 2004. Genetic improvement for prevention of beneficial trait deterioration in heterorhabditis bacteriophora through creation of inbred lines. Society for Invertebrate Pathology Annual Meeting Proceedings. p.104. Interpretive Summary: When live organisms are grown repeatedly in the laboratory or in industrial, beneficial characteristics can be lost due to potentially harmful genetic changes. We used a nematode (small round worm) that is used as an environmentally friendly pesticide to demonstrate that detrimental genetic changes can be prevented by creating inbred lines (groups that are the same genetically). Adoption of our technique could lead to improved natural pest control because nematodes kept as inbred lines would be resistant to harmful genetic changes. These results may be useful for improving the use of other natural pest control agents as well as other organisms that are routinely grown in the laboratory or in industry.
Technical Abstract: Continuous subculturing of organisms used for biological pest suppression can lead to detrimental genetic changes and loss of utility. In this study, we demonstrated that genetically homozygous inbred lines deter beneficial trail loss in the entomopathogenic nematode, Heterorhabditis bacteriophora. We created 22 inbred lines from a genetically diverse foundation strain. Three inbred lines and the foundation strain were repeatedly subcultured in vivo. Trait stability was evaluated after 6, 11, and 16 passages. After 16 passages the foundation strain exhibited more than 30% loss in biocontrol traits, i.e., virulence, reproductive capacity, heat tolerance, and host seeking ability. In contrast the three inbred lines were impervious to detectable changes in all beneficial traits. Creation of inbred lines may be a useful technique in maintaining beneficial traits of other biological pest control agents and other organisms that are routinely subcultured.