Malted barley (Hordeum vulgare) is a crucial component of beer, and it has been established that barley genotype has an effect on malting quality and beer flavor. This study extends this exploration by evaluating the effects of genotype, environment, and management on malting quality. Five fall-planted malting barley lines were grown in three locations, each representing a distinct growing environment in the Pacific Northwest (United States), and under nitrogen (N) treatments: control (N1) and N application at heading in addition to the control (N2). Genotype × location interactions were observed for all agronomic (yield, test weight) and grain quality metrics (grain protein, plumpness), and N treatment × genotype interactions were observed for grain protein and plumpness. Overall, N2 increased grain protein, without exceeding specifications, by almost 1% point. Based on random forest analysis, the major driver of all-malt index score was grain protein, followed by peak gelatinization temperature, germination energy, and water sensitivity. Still, over 70% of variation in all-malt index score was unexplained, which is likely due to genotype and location differences, as indicated by principal component analysis. This research confirms the agronomic potential of fall-planted malting barley in the Pacific Northwest and, although micromalted samples did not meet industry specifications, trends were identified that indicate the potential for these varieties at these locations. This research also demonstrates the potential of N management to fine-tune malting quality through grain protein, and that malting quality is influenced by genotype and environment, though many of the specific drivers remain unknown.

中文翻译：

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大麦籽粒蛋白质受基因型、环境和氮管理的影响，是麦芽质量的主要驱动因素

发芽大麦（Hordeum vulgare) 是啤酒的重要组成部分，并且已经确定大麦基因型对麦芽质量和啤酒风味有影响。本研究通过评估基因型、环境和管理对麦芽质量的影响来扩展这一探索。在三个地点种植了五个秋季种植的麦芽大麦品系，每个品系代表太平洋西北地区（美国）的独特生长环境，并且在氮（N）处理下：控制（N1）和除控制外的抽穗期施氮(N2)。在所有农艺（产量、容重）和谷物质量指标（谷物蛋白质、丰满度）中观察到基因型×位置相互作用，在谷物蛋白质和丰满度中观察到氮处理×基因型相互作用。总体而言，N2 在不超过规格的情况下将谷物蛋白质提高了近 1%。根据随机森林分析，全麦芽指数得分的主要驱动因素是谷物蛋白质，其次是峰值糊化温度、发芽能和水敏感性。尽管如此，如主成分分析所示，全麦芽指数得分中超过 70% 的变异无法解释，这可能是由于基因型和位置差异所致。这项研究证实了太平洋西北部秋季种植的麦芽大麦的农艺潜力，尽管微麦芽样品不符合行业规范，但确定的趋势表明这些品种在这些地区的潜力。这项研究还证明了氮管理通过谷物蛋白质微调麦芽质量的潜力，麦芽质量受基因型和环境的影响，尽管许多具体的驱动因素仍然未知。