Incorporating Desirable Genetic Characteristics From an Inferior Into a Superior Population Using Genomic Selection

Abstract

Resistance to specific diseases may be improved by crossing a recipient line with a donor line (a distantly related strain) that is characterized by the desirable trait. However, considerable losses in the total merit index are expected when crossing recipient and donor lines. Repeated backcrossing with the recipient line will improve total merit index, but usually at the expense of the newly introgressed disease resistance, especially if this is due to polygenic effects rather than to a known single major QTL. This study investigates the possibilities for a more detailed introgression program based on marker-trait associations using dense marker genotyping and genomic selection. Compared with classical selection, genomic selection increased genetic gain, with the largest effect on low heritability traits and on traits not recorded on selection candidates (due to within-family selection). Further, within a wide range of economic weights and initial differences in the total merit index between donor and recipient lines, genomic selection produced backcrossed lines that were similar or better than the purebred lines within three to five generations. When using classical selection in backcrossing schemes, the long-term genetic contribution of the donor line was low. Hence, such selection schemes would usually perform similarly to simple purebreeding selection schemes.

Quantitative trait loci (QTLs) analysis of palm oil fatty acid composition in an interspecific pseudo-backcross from Elaeis oleifera (H.B.K.) Cortés and oil palm (Elaeis guineensis Jacq.)

“…This minimizes the bias of marker effects and is allows capturing small effects. Odegard et al (2009) showed that GS could be efficient in introgressing a polygenic trait from an inferior to a superior population by backcrossing. As our pseudo-backcross used E. guineensis individuals from elite families, this is a relevant starting point to introgress the fatty acid profile of E. oleifera into breeding populations of E. guineeenis.…”

Genomic, Marker‐Assisted, and Pedigree‐BLUP Selection Methods for β‐Glucan Concentration in Elite Oat

“…The loss in genetic diversity can eventually lead to decreased genetic variance for the trait of interest and lower gain from selection (Robertson, 1960). In this case, a strategy which introgresses unrelated germplasm could be employed jointly with GS (Odegard et al, 2009;Bernardo, 2009). Another strategy would be a selection criterion that weights the low-frequency favorable alleles more heavily to avoid losing them.…”

Assessment of genomic selection for introgression of polledness into Holstein Friesian cattle by simulation

“…In aquaculture species, Odegard et al (2009b) demonstrated through computer simulation that GS is able to produce backcross lines that perform similarly or better than purebred lines within 3-5 generations. GS could be used to help to improve the genetic merit of polled cattle by shortening the generation interval and achieving a faster genetic progress compared to selection based on EBV estimation by BLUP.…”