Developing cultivars that use nitrogen more efficiently is a sustainable strategy for reducing nitrogen use in crop production. To assess the genetic diversity for nitrogen use efficiency (NUE) and related traits in potato, a total of 97 (88 for the Western-European market and 9 Ethiopian) cultivars were evaluated at two nitrogen levels (40 kg/ha and 120 kg/ha) for 24 quantitative traits in Debre-Tabor and Injibara (Ethiopia) in the 2013 main rainy season (June to September). Highly significant variation was found among genotypes for almost all measured traits. Plant height, NUE, tuber yield, and yield-related traits and model parameters for canopy development (maximum canopy covers area under the canopy curve) were significantly affected by N levels across locations. Dutch cultivars had more rapid initial canopy development and matured earlier than the Ethiopian cultivars at both N levels and locations. A hierarchical cluster analysis grouped the cultivars in 9 and 11 genetically distinct classes at low and high N, respectively. The genetic component accounted for a large portion of the phenotypic variation for plant height, tuber number per plant, average tuber weight, and NUE under both N regimes, as indicated by a high heritability. Strong phenotypic correlations were observed between NUE and tuber number per plant, days to maturity, tuber dry matter %, maximum canopy cover, and area under the canopy curve under both low and high N conditions. The result is indicative to set the best parental line selection criteria for crossing purpose and utilize the cultivars for further potato NUE breeding programmes.

中文翻译：

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不同氮肥条件下马铃薯品种氮素利用效率的遗传多样性

开发更有效地利用氮的栽培品种是减少作物生产中氮使用的可持续战略。为了评估马铃薯氮利用效率 (NUE) 和相关性状的遗传多样性，在两个氮水平（40 公斤/公顷和 120 公斤/公顷）下对总共 97 个（西欧市场 88 个和埃塞俄比亚市场 9 个）品种进行了评估。 ha) 2013 年主要雨季（6 月至 9 月）Debre-Tabor 和 Injibara（埃塞俄比亚）的 24 个数量性状。在几乎所有测量的性状的基因型中都发现了高度显着的变异。植株高度、NUE、块茎产量以及与产量相关的性状和冠层发育模型参数（冠层曲线下的最大冠层覆盖面积）受不同地点氮水平的显着影响。荷兰品种在 N 水平和位置都比埃塞俄比亚品种具有更快的初始冠层发育和成熟更早。层次聚类分析将栽培品种分别分为低氮和高氮的 9 个和 11 个遗传不同的类别。正如高遗传力所表明的，遗传成分在两种施氮方式下的植物高度、每株块茎数、平均块茎重量和 NUE 的表型变异中占很大一部分。在低氮和高氮条件下，NUE 与每株植物的块茎数、成熟天数、块茎干物质百分比、最大冠层盖度和冠层曲线下面积之间观察到很强的表型相关性。结果表明为杂交目的设定最佳亲本选择标准，并利用该品种进行进一步的马铃薯 NUE 育种计划。