ABSTRACT

Apple is an important fruit tree in semi-arid and arid regions, but increasing water scarcity limits apple production. Earlier studies have reported that partial root-zone irrigation (PRI) can increase water use efficiency (WUE), but the effects of PRI on fruit quality and nutritional value are still less known. To close this knowledge gap, a two-year field experiment conducted to evaluate the effect of PRI treatments on biochemical properties, WUE, and stomatal leaf traits in the Red Delicious and Braeburn apple cultivars. The results showed that alternate partial root-zone irrigation (APRI75) and fixed partial root-zone irrigation (FPRI75) increased WUE by about 20–36% compared to control, respectively, but there was no significant difference in WUE between control and FPRI50. The highest antioxidant capacity, phenolic compounds, and phenylalanine ammonia-lyase (PAL) activity recorded in PRI treatments compared to control. In addition to improving the WUE and maintaining the yield, using APRI75 and FPRI75 to irrigate apple trees could be more effective in improving antioxidant capacity and phytochemical compounds such as anthocyanins and leading to increased nutritive value and quality of the apple fruits. Therefore, APRD75 and FPRD75 as potential water savings strategies might be suitable for irrigation apple trees under water scarcity.

摘要

苹果是半干旱和干旱地区的重要果树，但日益严重的缺水限制了苹果的生产。早期的研究报告称，部分根区灌溉 (PRI) 可以提高水分利用效率 (WUE)，但 PRI 对果实质量和营养价值的影响仍然鲜为人知。为了缩小这一知识差距，进行了为期两年的田间试验，以评估 PRI 处理对 Red Delicious 和 Braeburn 苹果品种的生化特性、WUE 和气孔叶片性状的影响。结果表明，与对照相比，交替部分根区灌溉（APRI75）和固定部分根区灌溉（FPRI75）分别使 WUE 增加了约 20-36%，但对照和 FPRI50 之间的 WUE 没有显着差异。最高的抗氧化能力，酚类化合物，与对照相比，PRI 处理中记录的苯丙氨酸解氨酶 (PAL) 活性。除了提高 WUE 和保持产量外，使用 APRI75 和 FPRI75 灌溉苹果树可以更有效地提高抗氧化能力和花青素等植物化学物质，从而提高苹果果实的营养价值和品质。因此，APRD75 和 FPRD75 作为潜在的节水策略可能适用于缺水条件下灌溉苹果树。使用 APRI75 和 FPRI75 灌溉苹果树可以更有效地提高抗氧化能力和花青素等植物化学物质，从而提高苹果果实的营养价值和品质。因此，APRD75 和 FPRD75 作为潜在的节水策略可能适用于缺水条件下灌溉苹果树。使用 APRI75 和 FPRI75 灌溉苹果树可以更有效地提高抗氧化能力和花青素等植物化学物质，从而提高苹果果实的营养价值和品质。因此，APRD75 和 FPRD75 作为潜在的节水策略可能适用于缺水条件下灌溉苹果树。