Abstract:

To reveal the rule of mineral ions distribution of the Elaeagnus angustifolia Linn. in saline soil habitat to ensure the efficient planting and high yield, mature E. angustifolia grown in different salinity soils were used as study materials, the characteristics of absorption, transport and distribution of Na⁺, K⁺, Mg²⁺and Ca²⁺ in roots, branches and leaves were analyzed. The results showed that in saline soil environment, leaves of E. angustifolia had strong selective absorbing capacity for Ca²⁺ and Mg²⁺. In lower salt (from Grade I to II) soil environment, the Na⁺ content in leaves increased significantly, while in higher salt (from Grade III to IV) situation, Na⁺ absorbed in roots was more than that in branches and leaves. With the increase of soil salinity, the accumulation of K⁺, Ca²⁺ and Mg²⁺ in branches and leaves increased significantly. The capacity of mineral ions transportation from roots to branches and leaves increased in Grade I-III salinity soil environment, and this capacity was inhibited in Grade IV salinity soil environment. The values of K⁺/Na⁺and Mg²⁺/Na⁺in roots and branches increased first and then decreased. K⁺/Na⁺ and Mg²⁺/Na⁺ value in leaves had little variation, and the Ca²⁺/Na⁺ value in the roots and leaves varied greatly. The salt adaptation mechanism of mature E. angustifolia is mainly achieved by the accumulation of Na⁺ in roots and the enhanced selective absorbing capacity of K⁺, Mg²⁺ and Ca²⁺ in leaves, and also related to the relatively stable selective transport capacity of K⁺, Na⁺, Mg²⁺ and Ca²⁺in branches.

Key words: soil salinity grade, mineral ion homeostasis, ion absorption and distribution, selective transportation, salt ion accumulation, salt adaptation