Effect of NaCl treatment on the anatomy of Lycium ruthenicum leaves

The present study investigated the effects of NaCl treatment on the anatomy of Lycium ruthenicum leaves. The leaf anatomy was studied using paraffin sectioning, and the relationship between NaCl concentration and various anatomical parameters were analyzed. The results confirmed that L. ruthenicum is a typical salt-tolerant plant that possesses salt-resistant structures. With increasing NaCl concentration, the thickness of the leaves, palisade parenchyma and main veins increased, the thickness of the epidermis increased initially and then decreased, and the thickness of the spongy parenchyma decreased. When the NaCl concentration was 100 mmol·L^–1, the thicknesses of the upper and lower epidermises and the cell tense ratio of the leaf after 15 days were 67.72 μm, 44.39 μm, and 29.90%, respectively, and after 30 days were 79.70 μm, 55.99 μm, and 33.54%, respectively. However, with increasing NaCl concentrations, the thickness of the upper and lower epidermises and the CTR decreased. Meanwhile, no significant or regular changes were observed in the other indicators. Therefore, L. ruthenicum can grow normally at NaCl concentrations below 100 mmol·L^–1 but is adversely affected by higher concentrations.