Physiological and Biochemical Characterization of Linseed Genotypes under Salinity Stress

Linseed (Linum uistatissimum L.) is among the most valuable dual purpose oilseed crops and is used for the extraction of oil from seeds and fibers from plant's stems. Linseed has great adaptability, product diversity and researchers around the globe are conducting experiments for producing its bio-products. However, very scarce information is available regarding salinity tolerance in linseed. Therefore, diverse linseed germplasm was subjected to various rates of NaCl salt stress to assess their comparative performance and correlation between defense system and osmotic adjustment. Three salt treatments (control, 100 and 200 mM NaCl) were applied in hydroponic conditions and four linseed genotypes (two salt tolerant 637-72 and NO-303; two salt sensitive S-907 and C-99-3-115) were evaluated Salinity reduced induction of carbonic anhydrase and nitrate reductase (activities which may cause hampered growth in linseed genotypes. Linseed gradually improved the accumulation of glycine betaine and proline in cytosol with increasing salt stress, however, this accumulation was more for glycine betaine when compared with proline. An increased activity of antioxidant enzymes especially superoxide dismutase, peroxidase and ascorbate peroxidase played an important role in reducing lipid peroxidation and malondialdehyde contents in salt tolerant genotypes than salt sensitive genotypes with poor antioxidant system. A positive correlation of glycine betaine with the activity of superoxide dismutase indicated activation of antioxidative enzyme system to improve salt tolerance. Reduced malondialdehyde contents can be used as an important biochemical indicator for salt tolerance in linseed genotypes. (C) 2020 Friends Science Publishers