Salt tolerance of Hordeum and Brassica species during germination and early seedling growth

Abstract

Germination response and early seedling growth of barley (Hordeum vulgare L. 'Franklin', 'Harrington' and 'Abee'), wild barley (H. jubatum L.), canola (Brassica napus L. 'Excel') and wild mustard (B. kaber L. C. Wheeler) were investigated in iso-osmotic solutions of salts (NaCl, Na₂SO₄ + MgSO₄) and polyethylene glycol (PEG) with osmotic potentials close to −0.9 MPa. Germination of Harrington and wild barley was reduced most by the non-penetrating solute PEG, suggesting that ion penetration might have reduced osmotic stress in the salt treatments. Wild barley was more salt tolerant than Harrington based on seedling growth relative to control plants. Of the three barley cultivars, Franklin was similar in salt tolerance to Harrington, while Abee was the most sensitive to all osmotica tested. Barley varieties had the lowest germination rate and poorest seedling growth in the PEG treatment. Compared with canola, wild mustard showed consistently greater tolerance to all osmotica during germination and early seedling growth. Germination of the Brassica species was more sensitive to NaCl than to mixed sulphate salts. Additional calcium enhanced germination and improved seedling growth in Brassica species, especially in the PEG and NaCl treatments. Key words: Barley; calcium nutrition; canola; chloride salinity; sulphate salinity