Instituto de Conservación y Mejora de la Agrodiversidad Valenciana, Universitat Politècnica de València, Camino de Vera 14, 46022, Valencia, Spain.
Department of Agraria, University Mediterranea of Reggio Calabria Località Feo di Vito snc, 89124, Reggio, Calabria, Italy.
Plant Physiol Biochem. 2024 Mar;208:108447. doi: 10.1016/j.plaphy.2024.108447. Epub 2024 Feb 19.
Identification of novel genotypes with enhanced nitrogen use efficiency (NUE) is a key challenge for a sustainable tomato production. In this respect, the performance of a panel of thirty tomato accessions were evaluated under high (HN; 5 mM N) and low (LN; 0.5 mM N) nitrogen irrigation solutions. For each treatment, when 50% of plants reached the first flower bud stage, plant growth and biomass traits, chlorophyll, flavonol and anthocyanin indexes, nitrogen balance index (NBI), C:N ratio in leaves, stems, and roots, and NUE were evaluated. Significant (p < 0.05) effects were observed for accession, N treatment, and their interaction across all the traits. Under LN, plants showed a delayed development (40 days for HN vs. 65 days for LN) and reduced growth and biomass. On average, LN condition led to 41.8% decrease in nitrogen uptake efficiency (NUpE) but also 189.0% increase in NUtE, resulting in 62.2% overall increase in NUE. A broad range of variation among accessions was observed under both HN and LN conditions. Under LN conditions, chlorophyll index and NBI decreased, while flavonol and anthocyanin indexes increased. Leaf C:N ratio was positively correlated with nitrogen utilisation efficiency (NUtE) in both N treatments. Multi-trait analyses identified top-performing accessions under each condition, allowing to identify one accession among top performers under both conditions. Correlation analysis revealed that high root biomass and leaf C:N ratio are useful markers for selecting high NUE accessions. These findings offer valuable insights for improving tomato NUE under varying nitrogen fertilization conditions and for breeding high-NUE cultivars.
鉴定具有增强氮利用效率（NUE）的新型基因型是可持续番茄生产的关键挑战。在这方面，评估了 30 个番茄品系在高氮（HN；5 mM N）和低氮（LN；0.5 mM N）灌溉条件下的表现。对于每种处理，当 50%的植物达到第一个花芽阶段时，评估了植物生长和生物量特性、叶绿素、类黄酮和花青素指数、氮平衡指数（NBI）、叶片、茎和根中的 C:N 比以及 NUE。在所有性状中，均观察到品系、氮处理及其相互作用的显著（p < 0.05）影响。在 LN 下，植物发育延迟（HN 为 40 天，LN 为 65 天），生长和生物量减少。平均而言，LN 条件导致氮吸收效率（NUpE）降低 41.8%，但氮利用效率（NUtE）增加 189.0%，导致 NUE 总体增加 62.2%。在 HN 和 LN 条件下，均观察到品系间存在广泛的变异。在 LN 条件下，叶绿素指数和 NBI 降低，而类黄酮和花青素指数增加。叶片 C:N 比与两种氮处理中的氮利用效率（NUtE）呈正相关。多性状分析确定了每种条件下表现最好的品系，在两种条件下均能鉴定出一个表现最好的品系。相关分析表明，高根生物量和叶片 C:N 比是选择高 NUE 品系的有用标记。这些发现为在不同氮施肥条件下提高番茄 NUE 和培育高 NUE 品种提供了有价值的见解。
