Exploring the influence of saline-alkaline stress on germination and seedling growth traits of Arta (Calligonum comosum L. Herit) as influenced by saline-alkaline stresses

This research was conducted to study the effects of saline stress (9:1 M ratio of NaCl: Na₂SO₄, pH 6.27–6.49), alkaline stress (9:1 M ratio of NaHCO₃: Na₂CO₃, pH 9.11–9.25) and saline/alkaline combined stress (NaCl: Na₂SO₄:NaHCO₃: Na₂CO₃ 9:1:9:1, pH 8.94–9.17) using concentrations 25, 50, 75 and 100 mmol/L on seed germination and seedling growth traits of Calligonum comosum L’Her. The experiments were carried out in the laboratories of the Botany and Microbiology Department in the female university dormitory of the Science College, King Saud University. The results of seed germination included the percentage of seed germination, the lengths of both radicle and plumule, and both fresh and dry weights of the seedlings after 14 days of growth under stress treatments. Germination results indicated a significant gradual decrease in seed germination rates with an increase in the concentration of stress treatments, and seed germination was inhibited at concentrations higher than 100 mmol/L in all stress treatments. Also, there was a differential decrease in the parameters of seedling growth represented by the radicle and plumule lengths and both fresh and dry seedling weights with the increase in the concentrations and the greatest effect was the alkaline stress.