Marker-Assisted Breeding for Disease Resistance in Crop Plants

Abstract

Breeding disease-resistant crop varieties is a cornerstone of disease management. Marker-assisted selection (MAS) incorporates a plethora of plant genomic resources into the process of breeding disease-resistant crops. Although there are species-specific and disease-specific considerations, much of the procedures and theory behind MAS are conserved. Using molecular markers is most likely to increase the efficiency of the breeding process in cases where disease resistance is controlled by one or few genes, and those genes have a large effect on the resistance phenotype. In cases where disease resistance is controlled by many genes of small effect, genomic selection (GS) may be more efficient than MAS or pheno-typic selection. GS is an emerging technology, and many of the statistical principles and procedures are still being developed. This chapter should begin to inform breeders as to the potential and the details to consider if using a marker-assisted breeding tool in their plant breeding program. The genetic improvement of plant species for the benefit of humanity is an ongoing endeavor with a rich history and hope-filled future. Domestication traits were selected from natural variation within plant populations beginning in prehistory. Farmers continued selecting plant traits which improved agricultural outputs and increased quality for millennia. Beginning in the late nineteenth century, plant genetic improvement began to be practiced in a more organized fashion, now called