Effects of Different Salinity Levels on Growth, Yield and Physiology on Durum Wheat (Triticum turgidum var. durum)

Comparing the effects of salinity on durum wheat cultivars differing in their salt tolerance is of interest to physiologists investigating traits associated with adaptation to saline conditions and to breeders to develop cultivars for salt infected areas.This study was conducted to determine the effects of salinity on germination percentage, seedling growth, yield components, and physiological traits of two improved durum wheat cultivars (Triticum turgidum var. durum) developed by ICARDA durum breeding program namely, Belikh2 and Omrabi5. Plants were grown in greenhouse in sand cultures and irrigated with Hoagland s solution. Six salinity treatments were imposed by NaCl to the base nutrient solution. The treatments were 50, 100, 150, 200, 250, and 300 mM NaCl, along with a control treatment. Germination percentage and seedling growth were tested for both cultivars at the same mentioned treatments using a growth chamber. Germination percentage, seedling growth, vegetative growth, grain production, exclusion of Na+ and Cl-, and K+/Na+ ratio were higher in Belikh2 than Omrabi5 at 50, 100, 150, and 200 mM NaCl treatments. All seedlings of Omrabi5 did not survive more than 250 mM NaCl treatments whereas, Belikh2 survived indicating a high degree of salt tolerance. Therefore, these concentrations; 250 and 300 mM NaCl could be used efficiently to discriminate salt-tolerant varieties. These results showed that salinity tolerance in Belikh2 is largely attributable to the maintenance of higher K+ /Na+ ratio, and less Na + and Cl- accumulation