Abstract: By means of Enzyme Linked Immunosorhent Assay (ELISA), this paper analyzed the contents of endogenous hormones ABA, IAA, ZR, and GA₃ in Reaumuria trigyna and its related congener R. soongorica from four different salt habitats. In the identical habitats, the contents of growth-promoting hormones IAA, ZR, and GA₃ in R. trigyna were lower than those in R. soongorica, while the content of growth-suppressing hormone ABA was in contrary, which could be one of the main reasons that R. trigyna had a weaker ecological adaptability than R. soongorica. The (IAA+ZR+GA₃) /ABA in wild R. trigyna  varied with habitats, being saline soil > non-salinized soil > heavy solonchack, which was consistent with the density and coverage of R. trigyna  population being the largest on saline soil and followed by on non-salinized soil and heavy solonchack, and suggested that R. trigyna  having lived in saline habitat for a long time developed a corresponding inherent adaptation mechanism, and that the integrative regulation of endogenous hormones under salt stress played a key role for the growth and development of R. trigyna .

Key words: Reaumuria trigyna, R. soongorica, endogenous hormone, halophyte