Optimization of recurrent selection on the phenotypic value of doubled haploid lines.

Three methods of recurrent selection using doubled haploids (DH) are compared with the same resources: individual line selection (with one DH line per plant), selection between and within families, and selection index of family and line within family values. It seems that for low heritabilities at the individual level, the selection index method is the most efficient method, followed by the selection between and within families. Because of the difficulty in optimizing selection intensities, the selection between and within families can be less efficient than individual line selection. For very low heritabilities, it will be better to use selection index with a relatively low number of lines per haploidized plant, to minimize the rate of decrease of the effective population size. For a large range of situations, recurrent selection with only one DH line per plant seems one of the more efficient and the simpler methods.