Abstract:

Apocynum venetum, as an important salt-tolerant plant, has great application potential of soil ecological remediation and plant introduction & improvement in saline land. This study compared the salt-tolerance of Apocynum venetum seeds during germination and analyzed the difference in seed germination under different concentrations of salt stress. In the experiment, Apocynum venetum seeds were used as materials, and different concentration gradients of NaCl, Na₂SO₄, and NaHCO₃ were set for salt stress during the seed germination stage. The results showed that with the increase of salt concentration, the germination rate, germination potential and germination index of Apocynum venetum seeds decreased. The inhibitory effect of low concentration salt stress on the germination of Apocynum venetum was not significant, but the high concentration salt stress had a significant inhibitory effect. As the salt concentration increased, the initial germination time was postponed, NaCl had the most obvious delay effect on the initial germination time of Apocynum venetum seeds, followed by NaHCO₃, and Na₂SO₄ had the least effect. Apocynum venetum seed germination was more sensitive to NaCl,NaCl had the strongest inhibitory effect. At the same time, the delay effect of NaCl on the germination speed of seeds was higher than that of the other two salts. The suitable concentration range, half-lethal concentration and fatal concentration of Na₂SO₄ were higher than that of NaHCO₃ and NaCl. The fatal concentration of Na₂SO₄ could be 7.81%. Compared with Na⁺~Cl^- type saline soil, Apocynum venetum is more suitable for Na ⁺~SO₄^2- type saline soil.

Key words: Apocynum venetum, salt stress, seed germination, salt tolerance, saline soil, plant introduction