Abstract:Halocnermum strobilaceum, with the adaptability to saline habitats, is a dominant species in saline desert in Xinjiang. Effects of temperature and salt on root elongation and fresh weight of H. strobilaceum seedlings were studied through both field investigation and controlled experiments in laboratory. Our experiment applied three levels of temperature, two types of salt apply i.e. NaCl or soil multiple salts and six levels of salt concentration to seedling of H. strobilaceum. Compared with control, lower salt concentration which characterized as the electric conductance (E.C.) being lower than 6.25 dS/m significantly promoted root elongation, while root elongation was gradually inhibited by higher salt concentration (E.C.>6.25 dS/m). The diurnal temperature of 15/25 ℃ was the optimal temperature for root elongation, and growth of root was inhibited when the growing temperature was higher than this range. But the inhibition of root elongation varied with salt type. The seedling fresh weight (biomass) accumulation was favored at 15/35 ℃, but was not inhibited until 5/15 ℃. It was optimal for seedling biomass accumulation at E.C. being 9.38 dS/m. The interactions of temperature, salt concentration and salt type significantly influenced the seedling growth at early stage. NaCl inhibition to H. strobilaceum seedling growth was significantly higher than that of multiple salts at the same concentration, suggesting that antagonism may occur among ions in multiple salts solution and moderate the effects of ionic toxicity of single salt.