Effect of salinity on seed germination of Medicago sativa and Onobrychis sativa

This research was conducted to determine the salinity effects on seed germination characteristics in two species of Medicago sativa and Onobrychis sativa. For each species two genotypes were used by using a factorial experimental design including five salinity levels of 0,100, 200, 300 and 400 Mm NaCl and CaCl2 treatments. The treated seeds were assessed in laboratory conditions. Data were recorded and analyzed for percentage and speed of germination, length of root and shoot, seedling length; shoot to root ratio (S/R), vigour index and seedling dry weight. The results showed significant differences among salinity treatments for all of traits and between two species for speed of germination, length of root and shoot, seedling length under higher levels of salinity stresses. Species by salinity interaction effects were significant for speed of germination, length of root and shoot, seedling length and vigour index, indicating of different response of species for higher level of salinity stress. The higher variation between two species was obtained for seedling dry weight and R/S ratios. The higher values for germination percent were obtain in Lucerne in 100 Mm salinity. In sever stress (300 Mm), the sainfoin had higher values for germination percent.