Effects of abscisic acid on Reaumuria soongorica seed germination under NaCl stress

We explored the effects of abscisic acid (ABA) and NaCl stress on the germination characteristics of Reaumuria soongarica seeds using two-factor orthogonal experiments. Different ABA (0, 10, 20, 30, 40, and 50 mg·L⁻¹) and NaCl (0, 25, 50, 75 and 150 mmol·L⁻¹) concentrations were used. ABA and NaCl treatment had an considerable significant influence (P < 0.01) on germination rate and potential, vigor and germination index, and germ and root length. Furthermore, germination potential and rate were significantly affected by the interaction of ABA and NaCl (P < 0.01 and P < 0.05, respectively). NaCl (0～150 mmol·L⁻¹) stress and ABA (20 mg·L⁻¹) treament had the greatest effect on accelerating R. soongarica seed growth. Compared with those under 0 mg·L⁻¹ ABA and 25 mmol·L⁻¹ NaCl treatment, seeds under 20 mg·L⁻¹ ABA and 25 mmol·L⁻¹ NaCl treatment exhibited an increase in germination rate and potential, vigor and germination index, and germ and root length by 20.33%, 31.25%, 63.95%, 31.20%, 24.53%, and 41.98%, respectively. Hence, we advised that R. soongarica seeds should be soaked in 20 mg·L⁻¹ ABA in the further artificial auxiliary regeneration for 24 h before direct seeding for afforestation in desert areas, which presents an effective method of alleviating the damage caused by seed germination and seedling growth of R. soongarica seeds under NaCl treatment.