In multisite forest genetic experiments, the presence of genotype × environment interaction (GEI) is common. GEI may negatively affect the estimates of genetic variance and hamper selection decisions in tree breeding programs. Several measures exist to evaluate the stability of tested genotypes’ performance across environments with a choice of the method likely affecting breeders’ decisions. In this study, we evaluated variation in diameter and height growth performance in the progeny test established at 4 sites with 80 open-pollinated half-sib families of Scots pine. We found significant variation among examined progeny at age 10, reaching up to 31% for diameter and 20% for height depending on site, and significant GEI in both traits. We estimated contribution of each family to GEI using various methods and tools of GEI analysis—AMMI, GGE biplots, heterogeneity of regression coefficients (b_i’s), the deviation mean squares from regression (s²_di) and Kang’s yield-stability index (YS_i). Despite the presence of the cross-over interaction, family ranks did not vary much among sites. The selections based on the phenotype, YS_i and restricted b_i corresponded well to each other leading to the expected response to selection up to 7.8% on diameter and 4.4% on height, whereas those based on the AMMI stability variance were different and lead to a slight loss in both traits. We discuss our results in the context of the usefulness of those measures of genotype stability for tree breeding programs and propose the procedure to follow for making selection decisions in forest experiments with GEI.

在多地点森林遗传实验中，基因型×环境相互作用（GEI）的存在很常见。GEI 可能会对遗传方差的估计产生负面影响，并妨碍树木育种计划中的选择决策。存在多种措施来评估测试基因型在不同环境中的性能稳定性，并选择可能影响育种者决策的方法。在这项研究中，我们评估了在 4 个地点建立的后代测试中直径和高度生长性能的变化，这些测试地点有 80 个开放授粉的苏格兰松半同胞家族。我们发现在 10 岁时检查的后代之间存在显着差异，根据地点的不同，直径可达 31%，高度可达 20%，并且两个性状的 GEI 都显着。我们使用各种 GEI 分析方法和工具——AMMI、GGE 双标图、_i 's)、回归均方偏差 (s ² _di ) 和 Kang 的产量稳定性指数 (YS _i )。尽管存在交叉交互，但站点之间的家庭排名差异不大。基于表型的选择、YS _i和受限制的 b _i彼此很好地对应，导致对选择的预期响应高达 7.8% 的直径和 4.4% 的高度，而基于 AMMI 稳定性方差的选择不同并导致两个特性都有轻微的损失。我们在这些基因型稳定性测量对树木育种计划的有用性的背景下讨论了我们的结果，并提出了在 GEI 森林实验中做出选择决定的程序。