A genetic analysis of the London strain of rainbow trout

The London strain of rainbow trout (Oncorhynchus mykiss) was created by int erbreeding three other strains of rainbow trout and therefore was expected to have higher levels of genetic variation than other strains of rainbow tr out. We examined 129 London strain rainbow trout from Indiana by allozyme e lectrophoresis to assess levels of genetic variation and to examine the rel ationship between the London strain and other hatchery strains. When using the same loci to compare with other hatchery strains the London strain show ed levels of genetic variation within the range of other hatchery strains: mean heterozygosity of 0.053 (0.031-0.099), 1.27 (1.20-1.60) alleles per lo cus and 20.0% (20.0-40.0%) of the loci were polymorphic. The London strain is somewhat distinct from other hatchery strains (D = 0.009-0.072), in part because of the high frequency of the sIDHP*40 allele.