Salinity level influenced morpho-physiology and nutrient uptake of young citrus rootstocks

Yahia A Othman; Muayyad Bany Hani; Jamal Y Ayad; Rolston St Hilaire

doi:10.1016/j.heliyon.2023.e13336

Salinity level influenced morpho-physiology and nutrient uptake of young citrus rootstocks

Heliyon. 2023 Jan 31;9(2):e13336. doi: 10.1016/j.heliyon.2023.e13336. eCollection 2023 Feb.

Authors

Yahia A Othman¹, Muayyad Bany Hani², Jamal Y Ayad¹, Rolston St Hilaire³

Affiliations

¹ Department of Horticulture and Crop Science, The University of Jordan, Amman, Jordan.
² Department of Plant Production and Protection, Jerash University, Jerash, Jordan.
³ Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM, USA.

Abstract

Soil and irrigation water salinity are major limiting factor to citrus industry in arid environments. The objective of this study was to assess the effects of different salt stress levels on growth and ion uptake of three-month-old citrus rootstocks; sour orange (Citrus aurantium) and Volkamer lemon (Citrus volkameriana). Six levels of NaCl-salinity were used, 0.7 (control), 2, 4, 8, 12 and 15 dS m^-1. Salinity increment from 2.0 to 15.0 dS m^-1 significantly reduced seedlings height, stem diameter, leaf area, root dry weight, leaf relative water content, chlorophyll content index and chlorophyll fluorescence by one to three folds. In addition, leaf and root N concentration reduced by 10%-50%, P 6%-50%, K 8%-47%, Ca⁺² 7%-51% and Mg⁺² 7%-50% when salt stress in the irrigation water increased from 2.0 to 15.0 dS m^-1. Conversely, salt stress increment (2.0-15.0 dS m^-1) increased leaf stomatal resistance (5 folds), proline concentration (1 fold), Na⁺ and Cl^- in the leaf (10 fold) and root (4 fold) when compared to control (0.7 dS m^-1). In term of rootstock, Volkamer had higher seedling height, stem diameter, and root constituents (length, fresh and dry weight) than sour orange. While sour orange had higher leaf Cl^-, Ca⁺² and Mg⁺², Volkamer lemon had higher N, Na⁺, K⁺, and P. However, root nutrient (N, Na⁺, Cl^-, P and Mg⁺²) from Volkamer had consistently higher concentration compared to sour orange at 4.0, 8.0, 12.0 and 15.0 dS m^-1. Therefore, we believe that the Volkamer rootstock is more tolerant to salt stress than sour orange.

Keywords: Ions uptake; Lemon; NaCl; Salt stress; Sour orange.