SALT TOLERANCE OF HORDEUM AND BRASSICA SPECIES DURING GERMINATION ANDEARLY SEEDLING GROWTH

Germination response and early seedling growth of barley (Hordeum vulg are 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 reduc ed most by the non-penetrating solute PEG, suggesting that ion penetra tion might have reduced osmotic stress in the salt treatments. Wild ba rley was more salt tolerant than Harrington based on seedling growth r elative to control plants. Of the three barley cultivars, Franklin was similar in salt tolerance to Harrington, while Abee was the most sens itive to all osmotica tested. Barley varieties had the lowest germinat ion rate and poorest seedling growth in the PEG treatment. Compared wi th canola, wild mustard showed consistently greater tolerance to all o smotica during germination and early seedling growth. Germination of t he Brassica species was more sensitive to NaCl than to mixed sulphate salts. Additional calcium enhanced germination and improved seedling g rowth in Brassica species, especially in the PEG and NaCl treatments.