, Volume 142, Issue 4, pp 281–293 | Cite as

Multigenerational outbreeding effects in Chinook salmon (Oncorhynchus tshawytscha)

  • Sarah J. Lehnert
  • Oliver P. Love
  • Trevor E. Pitcher
  • Dennis M. Higgs
  • Daniel D. Heath


Outbreeding, mating between genetically divergent individuals, may result in negative fitness consequences for offspring via outbreeding depression. Outbreeding effects are of notable concern in salmonid research as outbreeding can have major implications for salmon aquaculture and conservation management. We therefore quantified outbreeding effects in two generations (F1 hybrids and F2 backcrossed hybrids) of Chinook salmon (Oncorhynchus tshawytscha) derived from captively-reared purebred lines that had been selectively bred for differential performance based on disease resistance and growth rate. Parental lines were crossed in 2009 to create purebred and reciprocal hybrid crosses (n = 53 families), and in 2010 parental and hybrid crosses were crossed to create purebred and backcrossed hybrid crosses (n = 66 families). Although we found significant genetic divergence between the parental lines (FST = 0.130), reciprocal F1 hybrids showed no evidence of outbreeding depression (hybrid breakdown) or favorable heterosis for weight, length, condition or survival. The F2 backcrossed hybrids showed no outbreeding depression for a suite of fitness related traits measured from egg to sexually mature adult life stages. Our study contributes to the current knowledge of outbreeding effects in salmonids and supports the need for more research to better comprehend the mechanisms driving outbreeding depression.


Outbreeding depression Heterosis Aquaculture Hybrid Backcrossing 



Yellow Island Aquaculture Ltd. provided experimental fish and facilities for the study. We are grateful to B. Coristine, B. Falica, A. Heath, C. Heath, J. Heath, K. Johnson, K. Jones and M. Wiper for assistance in the field and to C. Harris for assistance with hormone assays. This work was supported by the Collaborative Research and Development (CRD) and Discovery Grants from the Natural Sciences and Engineering Research Council of Canada (NSERC) and the University of Windsor (DDH). All research followed the University of Windsor and Canadian Council of Animal Care guidelines.


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Copyright information

© Springer International Publishing Switzerland 2014

Authors and Affiliations

  • Sarah J. Lehnert
    • 1
  • Oliver P. Love
    • 2
  • Trevor E. Pitcher
    • 1
    • 2
  • Dennis M. Higgs
    • 2
  • Daniel D. Heath
    • 1
    • 2
  1. 1.Great Lakes Institute for Environmental ResearchUniversity of WindsorOntarioCanada
  2. 2.Department of Biological SciencesUniversity of WindsorOntarioCanada

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