The effect of salinity on proline and carbohydrate contenets in three bread wheat genotypes (Triticum aestivum L.) in vegetative growth stage in hydroponic cultures

This study was carried out in 2009-2011, in the laboratories of science faculty - Tishreen University. The seeds of three genotypes: Sham8, Sakha8,AUS 29639 of bread wheat were planted in hydroponic cultures irrigated with Hoagland liquid in a growth chamber to compare the effect of three salt concentrations (0, 100,200 mm of NaCl) on proline and carbohydrate contents in three growth stages 21, 28, 35 of the experiment. There was an increase of proline and carbohydrate contents in all cultivars with increased salinity during the three growth stages of plants. Proline contents increased in Sham8 with low rates compare with Sakha8, AUS 29639. It increased in Sakha8 with the increase of salinity which reached 348% in the third growth stage in concentration 200 mm NaCl, while Proline concentration reached the highest value in AUS 29639 (524%). The carbohydrate content reached the highest value in Sakha8 in NaCl concentration 200 in the first growth stage (238070%) compared with the control, and (204.34%) in third stage in NaCl concentration 200mM compare with the control. The results of the study indicate the superiority of Sakha8, AUS 29639 in salt tolerance through accumulating suitable rates of proline and carbohydrates. AUS 29639 was more resistant to salt stress than Sakha8. We may use these results later in other physiological and genetical studies.

The effect of different concentrations of NaCl in seeds germination and early seedling growth of Lactuca plants cv. Kabous and Shinshar

This investigation was conducted at the laboratories of Horticulture Departments, Faculty of Agriculture to study the effect of different levels of salinity (NaCl) in the rate and the percentage of seed germination of lettuce, Lactuca sativa L. varieties: Shinshar and Kabous and to determine the seedling response to these levels of salinity with relative to root length, the length of the cold, fresh and dry weight of seedlings. NaCl was used at 0, 50, 100, 150 and 200 mM/l. Resulted showed that a gradual increase in salinity concentrations caused a gradual decline in all indicators studied in both cultivars. However, the plants of Kabous variety were less sensitive to the salinity and also higher than in the indicators studied for seedlings (rate of germination and percent, stems and roots length, fresh and dry weight of seedlings) under salt stress conditions.