Abstract
Elite single crosses are frequently identified through combining ability analysis of the results obtained from a diallel cross of selected inbred lines. The parents of these elite single crosses can be improved further by identifying a source of favourable alleles that are not present in the single cross. An unbiased estimator of the potential of an inbred line to donate favourable alleles, μa(B + G), that is easy to compute and free from the assumption of complete dominance, is proposed. The theory for the identification of donor inbred lines is based on a combining ability model. Five methods of identifying donor lines are compared theoretically with the proposed unbiased estimator. A worked example, based on a 12 x 12 diallel cross across two environments, illustrates the relationships between the various statistics used to identify donors. The unbiased estimator, μa(B + G), is shown to provide an appropriate means of identifying donor inbred lines.
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The authors gratefully acknowledge the assistance of the Agricultural Research Council (South Africa) in financing the field trials.
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Hohls, T., Clarke, G., Shanahan, P. et al. An unbiased estimator for identifying lines useful for the improvement of elite single crosses, based on a combining ability model. Heredity 75, 155–163 (1995). https://doi.org/10.1038/hdy.1995.118
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DOI: https://doi.org/10.1038/hdy.1995.118