Department of Zoology, Washington State University, Pullman, WA 99164-4236 USA
The aquaculture industry is in a novel position, in that significant natural populations of most cultured organisms still exist. These natural populations represent important sources of additional genetic variation that could be incorporated into breeding programs. In order to most effectively utilize the genetic variation of a given complex trait, the genetic architecture of the trait must be understood. In the culture of rainbow trout, development rate represents a complex trait which has significant implications for the culture of this commercially important species. The genetic basis of development rate is likely to involve multiple genes, ant temperature is an environmental variable that may influence the expression of this trait in a complex manner. To understand the genetic basis of development rate, multiple rainbow trout males from widely separated natural populations (Swanson River, AK; Skookumchuk River, WA; American River, CA) were crossed to domesticated females and the development rate of the resultant progeny was measured at 6°, 10°, and 14° C. Significant differences in development rate among populations were observed at all temperatures. In addition, the structure of the additive genetic variance-covariance matrix for development rate across temperatures was determined for each population. Significant differences in the proportion of additive genetic variance for development rate were observed among temperatures. These results, together with ongoing quantitative trait locus analyses using clonal lines derived from the Alaskan natural population, will provide a framework for understanding the genetic basis of development rate in rainbow trout. This could ultimately lead to efficient introduction of natural variation into cultured populations using techniques such as Marker Assisted Selection.
Plant & Animal Genome VII Conference Plant & Animal Genome VII Conference