47 Doubled Haploids versus Conventional Breeding in CIMMYT Wheat Breeding Programs

ABSTRACT Doubled haploid (DH) technology has been usedin breeding programs for several decades andis currently the method of choice in a numberof crop species, including barley (Hordeumvulgare L.), rapeseed (Brassica napus L.), maize(Zea mays L.), and wheat (Triticum aestivumL.). In this study we investigated via computersimulation the benefit of using DHscomparedwith the conventional wheat breeding strategyused at CIMMYT. Two strategies using DHswere considered: DH lines directly derived fromF1 hybrids (F1–DH), and DH lines derived from F3individuals that are retained following selectionfor agronomic traits in the F2 generation (F3–DH). Genetic gains per cycle, per year, andper dollar spent were consistently higher for conventional breeding than for DH breedingstrategies, especially gains per dollar. Thoughthe F1–DH strategy saved 1 yr in completing abreeding cycle, genetic gains per year for theadaptation trait from F1–DH were much lowerthan those from conventional breeding, wheretwo growing seasons are used per year. Thoughthe DH breeding strategy showed no significantadvantages over the conventional wheat shuttlebreedingregime of CIMMYT, we did not exclude the possibility that the DH breeding strategy mayhave advantages when genetic gains per unit of time are considered, and only one generation isgrown per year. The conventional shuttle regime will continue to be the major wheat breedingstrategy at CIMMYT, where two cycles can begrown per year and breeders can do selectionin large populations in both cycles.

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