Abstract: The seeds of desert plantTamarix taklamakanensiswere used as experimental materials. Different concentrations of NaCl, MgCl2, LiCl, and NaHCO3solutions were used for stress treatment to study the response of seed germination and seedling physiological characteristics to different types of salt, and to explore the mechanism ofT. taklamakanensisadapting to different types of saline-alkali soil, aiming to provide theoretical basis for the protection and breeding ofT. taklamakanensis, and the restoration of saline land vegetation. The results showed that as the concentration of different salt solutions increased, the germination rate, germination potential, germination index, and vigor index ofT. taklamakanensisseeds gradually decreased, while the relative salt damage rate gradually increased. The root length, bud length, and fresh weight ofT. taklamakanensisseedlings initially increased and then decreased with the increase of NaCl concentration. Low concentrations of NaCl (≤100 mmol/L) could promote the growth ofT. taklamakanensisseedlings. The degree of toxicity to the roots of seedlings was significantly higher than that to the shoots. The seeds ofT. taklamakanensisexhibited extremely high salt tolerance during germination, particularly strong tolerance to NaCl. With the increase of different salt concentrations, the activities of POD, SOD and CAT inT. taklamakanensisseedlings initially increased and then decreased, while the content of MDA increased, indicating thatT. taklamakanensisresponded to salt stress by dynamically regulation of the activity of antioxidant enzymes. The effects of four kinds of salt stress onT. taklamakanensiswere ranked as follows: NaHCO3> LiCl > MgCl2> NaCl, indicating that the toxicity of alkaline salt was stronger than that of neutral salt, and the toxicity of lithium salt was stronger than that of magnesium salt. Therefore,T. taklamakanensiswas suitable for introduction and cultivation in saline-alkali soil where chloride was the main component.

Key words: Tamarix taklamakanensis, saline-alkali stress, seed germination, physiological characteristics