Duranta repens salinity tolerance and foliar application with proline and ascorbic acid
El-Mahrouk EM, AI Abido, MK Gaber, A El-Sawy
Duranta repens L. is an evergreen shrub used for landscape gardens and hedges in some world regions. Due to the deficit of non-saline irrigation water, and fewer ornamental plants that encounter these obstacles; impair landscaping and gardening of these areas are expected. Therefore, Pot experiments were conducted during 2017 and 2018 seasons to investigate the impact of saline water which assigned as a main plot and the combinations of proline (Pr)+ ascorbic acid (AA) were assigned as a sub plot. The obtained results indicated that plants survival percentage was 100% till 2 g/l NaCl, while at 3-5 g/l NaCl the survival percentage was nil. The treatment of 1 g/l NaCl; caused a significant increases of studied plant vegetative growth characters in the first season compare to control treatment and 2 g/l NaCl. While higher significant values of such traits were recorded in the second season. However, control treatment showed some higher values for some other attributes during both seasons. In the second season, highly significant content of proline and leaf green color degree, Na and Cl (%) were resulted from the plants treated with 2 g/l NaCl. In terms of foliar application treatments, the gained results showed that 2 g/l Pr +0.3 g/l AA and control treatment; resulted in higher or lower significant values of vegetative growth traits and leaf green color degree and water content, respectively during both seasons. Higher significant proline, Na and Cl (%) contents were achieved by control treatment and due to apply the combined treatment of 1.0 g/l Pr + 0.2 g/l AA. Pertaining the interaction effect between the tested dependent variables, the presented results exhibited that the best results of vegetative growth traits and water content were obtained owing to irrigation the plants with 1 g/l NaCl in the first season and control treatment in the second one in combination with 2 g/l Pr + 0.3 g/l AA. While, higher significant percentages of carbohydrates, N, P and K; resulted from irrigation the plants with control treatment and spraying with 1 g/l Pr + 0.2 g/l AA; meanwhile, irrigation the plants with 2 g/l NaCl without foliar spraying; gave rise to higher significant proline content and Na and Cl (%). On the other side, 2 g/l NaCl in combination with 2 g/l Pr + 0.3 g/l AA treatment; achieved higher significant value of leaf green color degree during both seasons.