Markers linked to valuable traits are many and increasing in number. Together with decreasing costs of marker assays and the opportunity to outsource marker screening and avoid expensive setup costs, the potential to apply markers is becoming accessible to more and more breeding programs in developed and developing countries alike. This chapter outlines principles and provides formulas and tables to support breeders in designing crossing and selection methodologies incorporating marker-assisted selection. The focus is on inbreeding species or where inbreeding is used at certain stages of the breeding process as is common for hybrid crops. The best strategy will vary based on the objectives of the breeding program and the level and mix of resources available. The most efficient strategy can substantially reduce population sizes and cost needed to recover desirable genotypes or allow selection at the maximum number of loci for a given level of resource. Enriching rather than fixing alleles in early generations to avoid drift while minimizing population sizes is an important component of these strategies. However there are limits to how many desirable alleles can be combined in a single breeding cycle with even the most efficient strategy and this chapter allows a realistic assessment of what is possible.

Global Wheat Program

Text in English

INT2902

CIMMYT Staff Publications Collection