Navarro Josefa M, Antolinos Vera, Botía Pablo, Robles Juan M
Equipo de Riego y Fisiología del Estrés, Instituto Murciano de Investigación y Desarrollo Agrario y Medioambiental, 30150 Murcia, Spain.
Plants (Basel). 2023 Jun 13;12(12):2300. doi: 10.3390/plants12122300.
The use of desalinated seawater (DSW) for irrigation in semi-arid regions is taking hold. Citrus tolerance to ions that predominate in DSW and water stress depends on the rootstock. Deficit irrigation was applied to DSW-irrigated lemon trees and grafted on rootstocks with different tolerance ( (CM) and sour orange (SO)). Plants were irrigated with DSW or Control treatment (distilled water), and, 140 days later, irrigation treatments were started: full irrigation (FI) or DI (50% of the volume applied to FI). After 75 days, differences between CM and SO plants irrigated with DSW and under DI were found. The higher concentrations of Cl and Na in CM and B in SO were the main causes of shoot growth reduction. The osmotic adjustment of CM plants was made possible by the accumulation of Na, Cl, and proline, but SO failed to adjust osmotically. In CM and SO plants, photosynthesis reduction was due to lower chlorophyll levels, but also to stomatal factors (CM plants) or alterations of the photochemical machinery (SO plants). Finally, unlike CM, SO had a good antioxidant system. In the future, knowing the different responses of CM and SO under these stressful conditions could be useful in citrus-growing areas.
在半干旱地区，使用淡化海水（DSW）进行灌溉正逐渐普及。柑橘对DSW中占主导地位的离子以及水分胁迫的耐受性取决于砧木。对用DSW灌溉并嫁接在具有不同耐受性的砧木（卡里佐枳橙（CM）和酸橙（SO））上的柠檬树进行亏缺灌溉。植株分别用DSW或对照处理（蒸馏水）灌溉，140天后开始灌溉处理：充分灌溉（FI）或亏缺灌溉（DI，灌溉量为FI的50%）。75天后，发现用DSW灌溉且处于DI条件下的CM和SO植株之间存在差异。CM中较高的Cl和Na浓度以及SO中较高的B浓度是枝条生长减少的主要原因。CM植株通过积累Na、Cl和脯氨酸实现了渗透调节，但SO未能进行渗透调节。在CM和SO植株中，光合作用降低是由于叶绿素水平降低，也归因于气孔因素（CM植株）或光化学机制的改变（SO植株）。最后，与CM不同，SO具有良好的抗氧化系统。未来，了解CM和SO在这些胁迫条件下的不同反应对于柑橘种植区可能会有帮助。
