Wheat plants (Triticm aestirvum L.cv. Sakha 8) were treated with some bioregulators (proline 10& 20ppm) , Salicylic acid (50 & 100 ppm) and paclobutrazol (25ppm) ) with three salinity levels (0, 1000and 6000 ppm NaCl).
The results showed that, without bioregulators application, increasing NaCl levels increased root / shoot ratio to be 5 fold at 6000 ppm higher than control treatment. Adding the bioregulators obviously decreased the root/ shoot ratio under salt stress. Similar trend was detected for the grains yield (g) plant-1 at harvest stage. Whereas, the highest level of salinity caused a decrease of grain yield (g) plant-1 around 14 times lower than that obtained from control treatment. Meanwhile the bioregulator treatments reduces the harmful effect of salinity on grain yield (g) plant-1. Paclobutrazol gave the best positive effect under the highest salinity level but proline at 20 ppm concentration gave the lowest positive effect on the grain yield (g) plant-1 under the highest salinity level. Some physiological parameters such as total chlorophyll, total soluble sugars , free amino acids , indoles , phenols , proline, K and Na contents in leaves were tested as a physiological markers of wheat plants grown under salt stress. The results showed that, the K/Na ratio and indole content in leaves could be used as physiological markers for wheat plants grown under salt stress.