Stability of combining ability and the nature and extent of genetic and genotype × environment interaction is poorly understood in orchardgrass especially under climate change conditions. This study was conducted to evaluate the adaptability and yield stability of orchardgrass families in order to facilitate comparison among HS families and environments and identify suitable families for future breeding studies. In the present study, first-generation half-sib families of orchardgrass derived from the polycross of 25 parental genotypes were evaluated in the field during five years under two irrigation regimes of normal and water deficit. Considerable genotypic variation was observed among half-sib families for all of the evaluated traits, demonstrating high potential for improving these traits through half-sib mating. The effects of water deficit on dry forage yield increased from the first to fifth year and consequently declined the persistence of half-sib families. Results showed that both genetic and non-genetic gene actions played a role in the control of dry forage yield. The environment effect was a predominant source of variation which explained 58.6% of total variation, whereas G and GE captured 4.2% and 21.5%, respectively. The partitioning of GGE through GGE biplot analysis showed that the first two PC accounted for 65% and 11% of the GGE sum of squares respectively, explaining a total of 76% variation. The stability of general combining ability, plant productivity, and drought tolerance clearly identified G4, G5, G6, and G14 as the superior and stable parental genotypes able to transmit both stability and forage productivity to their progenies.

在果园草中，特别是在气候变化条件下，对配合力的稳定性以及遗传和基因型×环境相互作用的性质和程度知之甚少。本研究旨在评估果园科的适应性和产量稳定性，以促进 HS 科和环境之间的比较，并为未来的育种研究确定合适的科。在本研究中，在正常和缺水两种灌溉制度下，在田间评估了来自 25 个亲本基因型多交的果园草的第一代半同胞家族，为期五年。在所有评估性状的半同胞家族中观察到相当大的基因型变异，表明通过半同胞交配改善这些性状的潜力很大。水分亏缺对干草产量的影响从第 1 年到第 5 年增加，从而降低了半同胞家庭的持久性。结果表明，遗传和非遗传基因作用在干草产量的控制中都起作用。环境效应是变异的主要来源，它解释了总变异的 58.6%，而 G 和 GE 分别占 4.2% 和 21.5%。通过 GGE biplot 分析对 GGE 进行划分表明，前两个 PC 分别占 GGE 平方和的 65% 和 11%，解释了总共 76% 的变异。一般配合力、植物生产力和耐旱性的稳定性清楚地表明 G4、G5、G6 和 G14 是能够将稳定性和草料生产力传递给后代的优良和稳定的亲本基因型。