RESPONSES OF SALT-TOLERANT AND SALT-SENSITIVE LINES OF SAFFLOWER (CARTHAMUS-TINCTORIUS L) TO SALT STRESS

Two salt-tolerant (260622 and 305167) and two salt-sensitive (199952 and 170274) accessions of safflower (Carthamus tinctorius L.) were grown to maturity in sand culture salinized with 0 (control), 70, 140, and 210 mol m-3 NaCl. The two tolerant accessions produced significantly greater fresh and dry biomass, seed yield, and seed oil content than the two sensitive accessions. Salt-tolerant accessions accumulated significantly greater Na+ and free amino acids in the leaves than the two salt-sensitive accessions. The salt-tolerant accession 260622 also accumulated significantly greater soluble carbohydrates in the leaves compared with the other accessions. The salt-tolerant and salt-sensitive accessions did not differ in tissue Cl-, K+, and Ca2+ concentrations, K/Na ratios, K+ versus Na+ selectivity, leaf soluble proteins, and leaf proline. It was established that salt tolerance of safflower is associated with inclusion of Na+, and high accumulation of free amino acids in the leaves.