Abstract:

Using Elaeagnus angustifolia L. and Elaeagnus moorcroftii Wall. Ex Schlecht collected from Minqin region, Gansu Province as materials, their response to NaCl stress and their salinity threshold were investigated. The seedlings were cultured in plastic pots filled with sand containing 0, 0.3%, 0.6%, 0.9%, 1.2%, and 1.5% NaCl Hoagland solution. After 28 days, the plant height, fresh weight, dry weight, water content,and contents of Na ⁺and K ⁺ of different parts of the plants were measured. The results showed that the plant height, fresh weight and dry weight of two species declined with the increasing of NaCl concentration, and the E.angustifolia declined more than the E.moorcroftii under the same NaCl concentration. The water content of two species of Elaeagnus declined with increasing of NaCl concentration and the water content in shoots of two species of Elaeagnus had no significant difference under the same NaCl concentration, but the water content in roots of E.moorcroftii was significantly higher than that of E.angustifolia. The contents of Na ⁺ in shoots and roots of two species of Elaeagnus significantly increased with increasing NaCl concentration. Most of Na ⁺ was accumulated in roots, followed in mature leaves. The content of ions of E.moorcroftii was lower than that of E.angustifolia under the same NaCl concentration. It was concluded that the mechanism of salt tolerance of two species of Elaeagnus were the same. The salinity threshold of E.angustifolia was 0.96% (about 165mmol/L). The salinity threshold of E.moorcroftii was 1.30% (about 225mmol/L). The results showed the Elaeagnus had a better salt tolerance and the salt-tolerant mechanism was salt exclusion.

Key words: Elaeagnus angustifolia, Elaeagnus moorcroftii, NaCl stress, Salinity threshold