Plant Breeding and Genetics Section, School of Integrative Plant Sciences, Cornell University, Ithaca, NY, 14853, USA.
Plant Genome. 2021 Nov;14(3):e20138. doi: 10.1002/tpg2.20138. Epub 2021 Sep 5.
New breeding programs are faced with many challenges including evaluation of unknown germplasm, initiation of breeding populations that will satisfy short- and long-term breeding goals, and implementation of efficient phenotyping strategies for multiple traits. Genomic selection (GS) is a potentially valuable tool for recently established breeding programs to quickly accelerate genetic gain. Genomic selection on selection index (SI) values may increase gain over phenotypic selection but empirical studies remain limited. We compared gain in overall SI value for height, heading date, preharvest sprouting (PHS) resistance, and spot blotch resistance and component traits in two cycles of GS with one round of phenotypic selection (PS) in two-row spring malting barley (Hordeum vulgare L.). Higher realized gain for SI value, height, and PHS was observed with GS compared with PS but GS did not result in significant gain for heading date and spot blotch. Genetic variances for height and heading date, which had small index weights, were not reduced with GS but variances were substantially reduced for heavily weighted PHS and correlated seed germination traits. Inbreeding was increased by GS compared with PS but restricted mating of high breeding value individuals limited potential inbreeding. Our results indicate GS is a useful method to improve selection on index values with different weights.
新的育种计划面临着许多挑战，包括评估未知的种质资源、启动满足短期和长期育种目标的育种群体，以及实施针对多个性状的高效表型选择策略。基因组选择（GS）是最近建立的育种计划快速加速遗传增益的一种有潜力的有用工具。对选择指数（SI）值的基因组选择可能会比表型选择增加增益，但经验研究仍然有限。我们比较了在两轮 GS 和一轮表型选择（PS）中，对两排春大麦（Hordeum vulgare L.）的高度、抽穗期、抗穗发芽（PHS）和斑点叶斑病的总体 SI 值和组成性状的增益。与 PS 相比，GS 对 SI 值、高度和 PHS 的实现增益更高，但 GS 对抽穗期和斑点叶斑病没有显著增益。GS 并未降低高度和抽穗期的遗传方差，因为这些性状的指数权重较小，但 PHS 和相关的种子发芽性状的权重较大，方差显著降低。GS 比 PS 增加了近交，但限制高育种值个体的近亲交配限制了潜在的近交。我们的结果表明，GS 是一种有用的方法，可以改善具有不同权重的指数值的选择。
