Combining large multi‐environment trial (MET) datasets to decide which genotypes to move forward in the breeding process can be challenging, especially when dealing with negatively correlated traits. The use of a selection index has long been identified as an effective strategy in these situations. However, the method has found limited application in turfgrass breeding. The objective of this study was to use MET data for St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] breeding lines evaluated across the southern United States to compare genetic gains achieved with the additive additive genetic index (AI) versus the turf performance index (TPI) incorporating agronomic as well as consumer preference traits. The use of either selection index produced more positive genetic gains across traits than direct selection even in the presence of negative correlations. However, the higher genetic gains obtained with AI versus TPI indicate that the use of an index that weighs traits according to their importance is a better approach for selection. Moreover, under a more stringent selection intensity, none of the best lines identified with AI would have been selected with TPI emphasizing the importance of choosing selection criteria that provide a more nuanced ranking of lines. Additionally, higher heritability values and gains from selection were obtained for turfgrass quality under stress (drought and shade) than under normal conditions indicating that selection under stress environments might be more efficient. Most of the evaluated St. Augustinegrass lines outperformed the checks, further supporting the value of cross‐institutional breeding collaborations.

中文翻译：

---

在圣奥古斯丁草育种中最大限度地提高农艺和消费者偏好性状的遗传增益


结合大型多环境试验 （MET） 数据集来决定在育种过程中推进哪些基因型可能具有挑战性，尤其是在处理负相关性状时。在这些情况下，使用选择索引长期以来一直被认为是一种有效的策略。然而，该方法在草坪草育种中的应用有限。本研究的目的是使用圣奥古斯丁草 [Stenotaphrum secundatum （Walt.）Kuntze] 育种品系在美国南部进行了评估，以比较使用加性加性遗传指数 （AI） 与结合农艺和消费者偏好性状的草坪性能指数 （TPI） 实现的遗传增益。即使在存在负相关性的情况下，使用任一选择指数也比直接选择产生更多的性状正遗传增益。然而，与 TPI 相比，AI 获得的更高遗传增益表明，使用根据性状重要性加权的指数是一种更好的选择方法。此外，在更严格的选择强度下，用 AI 识别的最佳品系都不会被选择，TPI 强调选择提供更细致入微的品系排名的选择标准的重要性。此外，在胁迫（干旱和阴凉）下，草坪草质量的遗传力值和选择收益高于正常条件下，这表明在胁迫环境中的选择可能更有效。大多数评估的 St. Augustinegrass 品系的表现优于检查，进一步支持了跨机构育种合作的价值。