Effects of Exogenous Spermine on Seed Germination and Early Growth of Sunflower Seeds Under Salinity Stress

The effects of various concentrations (0.01, 1, 2mM) of spermine (Spm) on germination and some early growth parameters of sunflower ( Helianthus annuus L. cv. Santafe) seeds were investigated in media containing different concentrations of NaCl (50, 100, 200mM). Regardless of its concentrations, application of Spm under non-saline conditions remained ineffective on germination percentage as well as on the early growth parameters studied (length of radicle, fresh and dry weights). The salt, depending on its concentration, inhibited or delayed the germination to a great extent. The growth parameters studied in the early growth period were also adversely affected by salt treatment. However, at 200mM NaCl, Spm at concentrations of 0.01 and/or 1mM completely overcame the germination-inhibiting effect of salt, so that the germinations in these two combinations, as compared to their controls, increased as much as 8 fold. On the other hand, the fresh weight increased in 50mM NaCl+0.01mM Spm and 100mM NaCl+1mM Spm combinations while the dry weight increased only in 50mM NaCl+0.01mM Spm combination. However, all salt+Spm combinations were found to be ineffective on the length of the radicle.

Effects of Exogenous Spermine on Seed Germination and Early Growth of Sunflower Seeds Under Salinity Stress

The effects of various concentrations (0.01, 1, 2mM) of spermine (Spm) on germination and some early growth parameters of sunflower ( Helianthus annuus L. cv. Santafe) seeds were investigated in media containing different concentrations of NaCl (50, 100, 200mM). Regardless of its concentrations, application of Spm under non-saline conditions remained ineffective on germination percentage as well as on the early growth parameters studied (length of radicle, fresh and dry weights). The salt, depending on its concentration, inhibited or delayed the germination to a great extent. The growth parameters studied in the early growth period were also adversely affected by salt treatment. However, at 200mM NaCl, Spm at concentrations of 0.01 and/or 1mM completely overcame the germination-inhibiting effect of salt, so that the germinations in these two combinations, as compared to their controls, increased as much as 8 fold. On the other hand, the fresh weight increased in 50mM NaCl+0.01mM Spm and 100mM NaCl+1mM Spm combinations while the dry weight increased only in 50mM NaCl+0.01mM Spm combination. However, all salt+Spm combinations were found to be ineffective on the length of the radicle.