Selective Breeding and Identification of Quantitative Trait Loci (QTLs) associated with Body Weight in a Domesticated Strain of Coho salmon

Description

Globally, enhancement of performance traits for finfish aquaculture has utilized traditional quantitative genetics methods that can result in significant gains (~5-10%) per generation. With the advent of genomics, molecular genetic marker-based selection procedures are now being utilized in selective breeding programs for plant and animal agricultural species. These approaches seek to identify specific genetic loci controlling traits of interest, and develop tightly linked molecular markers that can be used to directly select for alleles conferring enhanced performance. Analysis of the genetic basis of growth in coho salmon and rainbow trout has revealed that this trait is largely controlled by additive genetic variance, making it likely that QTL-based controls of growth rate will be found in these two species using family analyses of phenotypic variation coupled with molecular genetics.

QTLs for application in a species can be identified de novo by genetic mapping of an array of molecular markers within families displaying quantitative variation for a trait of interest. This method is certain but expensive. A second approach, now becoming feasible for salmonid fishes, involves the testing of QTL markers previously identified in one species to closely related species. Researchers in the Ferguson and Danzmann labs at the University of Guelph are convincingly showing that QTL marker loci (such as microsatellites and SNPs) identified in one salmonid species are likely to be associated with control of the same trait in other salmonids . This approach provides a cost-effective alternative to the de novo development of QTLs independently for each species. We will utilize QTLs developed de novo in rainbow trout (and Arctic char and Atlantic salmon) to determine if the same loci identify QTLs for body weight in domesticated coho salmon, and subsequently apply them in a broodstock development program.

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)

Year(s)

2007 - 2010

Ecoregion(s)

Pacific: Vancouver Island West Coast

Principal Investigator(s)

Ruth Withler
Email: Ruth.Withler@dfo-mpo.gc.ca