| To reveal the physiological mechanism of salt alkali tolerance of ‘Junzao’ Jujube based on characteristics of nutrient absorption, utilization, and accumulation in ‘Junzao’ Jujube trees, the content of mineral elements such as N, P, K, Ca, Mg, Fe, Mn, Zn, Cu, Na in organs of ‘Junzao’ Jujube under different concentrations of salt alkali treatment was measured. The characteristics of nutrient absorption, accumulation, and transportation distribution in different organs of ‘Junzao’ Jujube were analyzed. The results showed that mineral ions were mainly concentrated in the main roots and perennial branches under salt alkali stress. With and without salt alkali stress, Na+ mainly gathered in the main roots of ‘Junzao’ Jujube, and the K+ concentration was highest in the leaves, which can maintain a high K+/Na+ concentration. The transport capacity of Mg and Ca was enhanced at low concentrations of saline alkali (60 mmol·L-1). Under high concentration saline alkali (180 mmol·L-1), the transport capacity of Mg and Ca from fibrous roots to leaves significantly decreased by 44.7% and 33.1%, and the Ca2+/Na+ and Mg2+/Na+ values in leaves significantly decreased by 72.8% and 71.6%, but still greater than 1. In other organs, K+/Na+, Ca2+/Na+ and Mg2+/Na+ remained stable and greater than 1. Compared with CK, the Mn and Fe content in the annual branches and the Mg content in the perennial branches increased by 14.01%, 11.11%, and 10.52% respectively under high concentration saline alkali. The content of Cu, Zn, Mn, and Fe in the fibrous roots increased by 117.53%, 25.65%, 84.98%, and 26.19%, while the content of N, P, Zn, Mn, Fe, and Ca in the main roots decreased by 23.07%, 15.38%, 80.48%, 49.58%, 8.82%, and 30.44%. The results indicated that the salt adaptation mechanism of adult ‘Junzao’ Jujube was mainly achieved through the accumulation of Na+ by roots and the enhanced selective absorption ability of K, Mg, and Ca by leaves. |