Water deficiency is an important abiotic stress that often linked with other major abiotic stresses as heat stress, salinity stress, etc. Thus, it is considered as one of the main factors responsible of reduction crop productivity. Egypt presents a distinctive example of drought problem faced in some arid and semi-arid regions. Thus, water conserving becoming a crucial consideration for agriculture. Two field experiments were conducted during two successive seasons at the Research and Production Station of National Research Centre, Nubaryia district, Beheira Governorate, Egypt to investigate the physiological role of proline with 12.5 & 25mM concentrations in improving growth, some biochemical, osmolytes compounds and yield as well as seed nutritional values and quality of quinoa plant under normal and water deficit conditions. Skipping irrigation two times led to marked decreases in growth criteria, photosynthetic pigments, endogenous indole acetic acid (IAA), yield quantity and quality. Meanwhile, increase phenolics, total soluble sugars, proline and free amino acids contents of quinoa leaves.On the other hand, exogenous application of proline led to marked increases in growth characters (plant height, shoot, root fresh and dry weight) concomitantly with increasing the levels of photosynthetic pigments, IAA, phenolics, free amino acid and proline contents as compared with untreated plants. Moreover, different treatments increased seed yield and its components, also marked increases in nutritional values of the yielded seed (carbohydrate contents, protein%, oil, flavonoids and antioxidant activity). It is noticed that higher concentrations of 25 mM proline was more pronounced than lower concentration in increasing most of the tested parameters of quinoa plant. |
