Objective: Given the extent of saline lands worldwide, this study aimed to evaluate the tolerance of Persian Camelthorn (Alhagi camelorum) to salinity stress during germination and early growth stages following seed hardness removal, to promote its cultivation as a forage plant for livestock.
Method: A factorial experiment was conducted in a completely randomized design with four replications in 2023 at the Seed Analysis Laboratory of the Seed and Plant Certification and Registration Institute. Factors included: (1) seed population (Gorgan and Mashhad), (2) salinity levels (0, 100, and 200 mM NaCl), and (3) seed hardness removal treatments (immersion in 100°C water for 1 minute and concentrated sulfuric acid for 35 minutes). Germination percentage, mean daily germination time, seedling vigor index, stem length, and superoxide dismutase (SOD) activity were measured.
Results: Salinity stress significantly reduced germination percentage, as well as stem length. Germination indices differed significantly between control and 200 mM treatments. Increasing salinity decreased mean daily germination in all treatments. The highest salinity level reduced stem length by 65% and 44% in the Mashhad population, and 71% and 64% in the Gorgan population, compared to control, respectively. Treatment with 100°C water and 200 mM salinity increased SOD activity by 56.9% in the Mashhad population and 45.4% in the Gorgan population. Sulfuric acid treatment with 200 mM salinity increased SOD activity by 25.4% and 13.0% in Mashhad and Gorgan populations, respectively.
Conclusions: Sulfuric acid treatment for 35 minutes significantly increased germination percentage in both populations compared to 100°C water treatment. The greater increase in SOD activity in the Mashhad population suggests higher salinity tolerance, making it a suitable candidate for cultivation in saline lands.

Highlights

• Sulfuric acid (35 min) and hot water (100°C, 1 min) effectively broke seed dormancy and improved germination.
• The Mashhad population was more salt-tolerant than the Gorgan population.
• Both populations countered salinity through enhanced antioxidant enzyme activity.