EFFICIENT INTEGRATION OF MOLECULAR AND CONVENTIONAL BREEDING METHODOLOGIES

摘要

Molecular markers make it possible for breeders to combine desirable alleles at agreater number of loci and at earlier generations than is possible with conventionalbreeding methodologies. With an increasing number of markers for important traits,marker assisted selection (MAS) strategies that minimize population sizes and assaynumbers while ensuring important alleles are not lost become increasingly important.In practical breeding, strategies will often have to balance MAS with the need to retainvariability for important traits that are selected partly or wholly by conventional meansThis paper will discuss strategies to maximize the number of traits that can becombined in a single breeding cycle taking account of practical limits such as reasonablepopulation sizes that can be managed in a breeding program. Examples from ourbreeding program and mapping populations will be used to illustrate the effects ofdifferent MAS strategies on population size and levels of residual genetic variation atunselected loci. It is these unselected loci that become important where conventionalselection follows MAS.