Genomewide selection with minimal crossing in self-pollinated crops

Genomewide selection in plants has focused on cross-pollinated species, such as maize (Zea mays L.), in which selected plants can be easily crossed to obtain a large number of seeds for the next cycle of selection. Here I describe and present simulation results for a genomewide selection procedure that requires minimal crossing in self-pollinated crops. This procedure, referred to as GWS_Self, involves producing only a few F₁ seeds from crosses among the selected progenies in Cycle 0, allowing the F₁ seeds to naturally self-pollinate to produce F₂ seeds, conducting marker-based selection among the resulting F₂ plants, and repeating this select-recombine-self procedure in a yearround nursery or greenhouse. With barley (Hordeum vulgare L.) as a model species, I found from simulation experiments that selection responses with GWS_Self were 81 to 87% of the responses obtained if genomewide selection procedures appropriate for maize were used. These lower responses can be compensated for by more stringent selection.