Correlated response of flesh color to selection for harvest weight in coho salmon (Oncorhynchus kisutch)

Abstract

Chilean coho salmon (Oncorhynchus kisutch) represents about 90% of the worldwide production. From a commercial perspective rapid growth to market weights and product quality are important aspects of profitability. The objective of this study was to determine genetic parameters, genetic trends and correlated response of flesh color (FC) after eight generations of selection for harvest weight (HW) in two coho salmon populations spawning independently in even and odd years. A total of 41,597 and 37,319 records for HW and 4946 and 6731 for FCwere included in the analysis for the even and odd populations, respectively. A linear bivariate animal modelwas used to estimate genetic parameters and compute breeding values for both traits. Estimated heritabilities for HWand FCwere 0.41 +/- 0.03 and 0.08 +/- 0.02 in the even population and 0.22 +/- 0.03 and 0.04 +/- 0.01 the in odd population, respectively. Genetic and phenotypic correlations betweenHW and FC were 0.15 +/- 0.11 and 0.07 +/- 0.02 in the even population and 0.25 +/- 0.14 and 0.12 +/- 0.02 in odd population, respectively. Response to selection was measured as the slope of the linear regression fitted on the mean breeding values per generation per trait. We found a positive genetic trend for both traits after eight generations of selection for HW. The increase in HW per generation was 0.31 +/- 0.01 and 0.26 +/- 0.02 kg for the even and odd populations, respectively. The correlated increase in FC was 0.04 +/- 0.01 and 0.04 +/- 0.00 fan units per generation in the even and odd population, respectively, showing that selection for HWcan increase FC.

Statement of relevance.

Correlated response in color to selection for growth in coho