The genus Cynodon includes species that have huge potential to produce high-quality fodder, for grazing and hay production. In perennial forage breeding, selection should be performed based on repeated measurements in the same individual over time, which maximizes the selective efficiency. Thus, the objectives of this study were to estimate the coefficients of repeatability and optimal number of measures for the genetic selection of Cynodon spp. clones. We evaluated 202 clones, being five checks, during four harvests, in augmented block design. A mixed model methodology (REML/BLUP) was used to estimate the variance components and predict the genotypic values. The repeatability coefficient for plant height, green weight, dry matter, and plant vigor were equal to 0.50, 0.67, 0.25, and 0.73, respectively. The accuracies obtained by performing m repeated measures revealed that 5, 2, 13, and 2 measurements are required to attain an accuracy ≥ 90% in genetic gain from the selection for plant height, green weight, dry matter, and plant vigor, respectively. Furthermore, the efficiency of performing four measurements compared with that of performing only one measurement was 27%, 15%, 51%, and 12% for plant height, green weight, dry matter, and vigor, respectively. In addition, the additive index, adopting a 10% selection intensity, was used in simultaneous selection, leading to desirable genetic gains for plant height, green weight, and plant vigor. In conclusion, the use of the repeatability coefficient suggests performing three measurements to obtain a high accuracy and good efficiency on the selection of superior genotypes of Cynodon spp.

中文翻译：

---

犬齿兽属遗传选择的重复性系数和最佳措施数的估计。

犬齿龙属包括具有生产优质饲料、用于放牧和干草生产的巨大潜力的物种。在多年生牧草育种中，应根据同一个体随时间重复测量进行选择，以最大限度地提高选择效率。因此，本研究的目的是估计犬齿兽属遗传选择的重复性系数和最佳措施数。克隆。我们评估了 202 个克隆，在四次收获期间进行了五次检查，采用增强块设计。混合模型方法 (REML/BLUP) 用于估计方差分量并预测基因型值。株高、绿重、干物质和植物活力的重复性系数分别等于 0.50、0.67、0.25 和 0.73。通过执行 m 次重复测量获得的准确度表明，分别需要 5、2、13 和 2 次测量才能从植物高度、绿重、干物质和植物活力的选择中获得≥ 90% 的遗传增益准确度。此外，与仅进行一次测量相比，进行四次测量的效率分别为 27%、15%、51% 和 12% 的株高、绿重、干物质和活力。此外，加性指数采用 10% 的选择强度，用于同步选择，导致植物高度、绿重和植物活力的理想遗传增益。总之，重复性系数的使用建议执行三个测量以获得在选择狗牙属的优良基因型方面的高准确度和良好效率。