Salt Tolerance Of The Dense Branches Tamarix

Phenotypic and physiological parameters of dense branches Tamarisk and Tamarisk chinensis Lour under salt stress conditions were measured to evaluate the salt tolerant and application potential. Paired comparison test and randomized block were used in experiment design. There were ten salinity treatments, namely 0%(CK)、1.2%、1.6%、2.0%、2.4%、2.8%、3.2%、3.6%、4.0%、4.4%. Growth traits,such as biomass, growth rate, survival rate and salt resistance performance and physiological traits, such as photosynthesis, root activity, chlorophyll content, leaf conductivity, the decreasing rate of conductivity of the solution, were measured. And then paraffin section on the stem and leaf of dense branches Tamarisk and Tamarisk chinensis Lour were completed and observed. The main conclusions are as follows:(1) Dense branches Tamarisk and Tamarisk chinensis Lour have strong salt tolerance. There were several survivals under the circumstances of 4.4% salt concentration.(2) Biomass, growth rate, survival rate and salt tolerance table values of dense branches Tamarisk and Tamarisk chinensis Lour were both decreasing along with the increasing salt concentration. There were no significant differences between these two kinds of materials.(3) With the increasing of salt concentration, Pn, Tr, Gs of dense branches Tamarisk and Tamarisk chinensis Lour decreased while the Ci increased, the chlorophyll content of leaves decreased, the relative leakage rate and damage rate increased gradually, the root activity reached the peak under the circumstances of1.2% salt concentration.(4) Stem and leaf anatomical structure of dense branches Tamarisk and Tamarisk chinensis Lour showed high degree of adaptability with salt stress environment. With the increase of salt concentration, the leaf epidermal cells of palisade tissue from arranged shapely into irregular shape gradually, palisade cell and cortex cell layer increase. The leaf epidermis have well-developed salt glands.Epidermal cells changed from rectangle into irregular rough shape, the outertangential wall of the epidermal stem cells present projecting, papillae formation,thickening and rough. Proportion of the stem, which is occupied by the medullary area decreased gradually with the increase of salt concentration.(5) When the salt concentration was 0%~2.4%, the main cause of the photosynthetic rate declining may be stomatal limitation. When the salt concentration was 2.8%~4.4%, the photosynthetic rate declining may be affected by both of stomatal and non-stomatal factors. Salt stress tolerance of two types of Tamarix inflection point are between the salt concentration of 3.2% ~ 3.6%.