Abstract:Tamarix chinensis is a dominant shrub in the Yellow River Delta region. Salt glands occur on the leaves of T. chinensis, which can effectively exclude salt from the plant. However, due to the effects of global climate change and human over-exploitation of seawater resources, soil salinization and degradation has occurred in this region. The growth of T. chinensis has gradually decreased under conditions of high soil osmotic pressure, poor aeration and moisture, low nutrient availability, and high soil salinity. However, the roots can directly sense soil salinity changes, which mean that the effect of differing salinity on the eco-physiological characteristics of roots of T. chinensis cuttings is very important for the ecological restoration of coastal wetlands. In the present study, we studied the effects of different salinities (0.0, 0.4%, 0.8%, 1.2%, 2.4%, 3.6% NaCl solutions) on the eco-physiological characteristics of roots of 1-year old T. chinensis. To explore the response of T. chinensis root growth and eco-physiological characteristics to different salinity levels, the rooting rate of T. chinensis cuttings, root lifespan, root number, root length, aboveground biomass, root biomass, hydrogen peroxide enzyme (CAT) activity, adenosine triphosphate (ATP) synthase, and the content of abscisic acid were determined. The results revealed that (1) the rooting rate was approximately 83% in the 0.8% NaCl treatment, and the rooting rate and life of the root decreased significantly when the salinity increased to greater than 0.8%; (2) the root length gradually decreased with increasing salinity, while the root quantity initially increased and then decreased with increasing salinity once the salinity was greater than 1.2%; (3) examining the biomass allocation pattern of T. chinensis adjustment to acclimate to salinity conditions, the aboveground biomass was higher than root biomass at lower salinity and the proportion of root biomass increased gradually; however, was still less than the aboveground biomass; and (4) the activity of ATP synthase and CAT increased when salinity was less than 0.8%, and the activities decreased when the salt content was greater than 0.8%. In addition, the content of abscisic acid increased with increasing salinity and then decreased when the salinity increased to greater than 1.2%.