Marker-assisted backcrossing for simultaneous introgression of two genes

Publikations-Art

Zeitschriftenbeitrag

Autoren

Frisch, M., and A.E. Melchinger

Erscheinungsjahr

2001

Veröffentlicht in

Crop Sci. 41: 1716-1725

Marker-assisted selection is used to accelerate recovery of the recurrent parent genome (RPG) in backcross programs. Our objectives were to compare various selection strategies and breeding plans for the simultaneous introgression of two genes with respect to the RPG recovered and the number of marker data points (MDP) required. Computer simulations were performed with a published genetic map in maize (Zea mays L.) consisting of 80 markers and assuming selection for dominant target genes on the basis of phenotypic evaluation. For unlinked as well as for linked target genes, a shortening of the backcross program from six to three generations resulted from applying marker-assisted background selection. In breeding programs with three backcross generations, the least MDP were required when (i) applying selection strategies consisting of three or four selection steps on the basis of presence of the target genes and selection indices calculated from the marker genotype, (ii) increasing the population size from early to advanced generations, and (iii) merging the target genes in an early generation. These principles can be used for optimizing the design of marker-assisted backcross programs for the simultaneous introgression of two genes.