responsed of citrus aurantium seedlings to treatment with paclobutrazole (PBZ) under saline stress conditions

Abstract

The research was conducted in Ciano Research Station /Agricultural Scientific Research Center in Lattakia, during the years 2020-2021 and 2021-2022. to study the effect of treatment with paclobutrazole (PBZ) in five concentrations (0, 250, 500, 1000, 2000 ppm) on the growth of citrus aurantium seedling, under five levels of salinity (0, 8, 16, 24, 32 mSiemens/cm). For mitigate the damage caused by soil salinization, and the possibility of irrigation with water containing a specific percentage of salts.
The results showed that the gradual increase in salt levels resulted in a gradual decrease in all studied parameters. Treatment with paclobutrazole improved studied parameters compared to all other treatments. The interaction between salt and paclobutrazole concerning the interaction treatment, using of PBZ (2000ppm) significantly increased roots length (34. 75 cm). Fresh and dry weight of vegetative total (49.26, 21.74 g respectively), comparing with the other treatments and with control (25.87, 11.54g respectively). fresh and dry weight of root total (32.92, 14.21 g respectively) comparing with the other treatments and with control (22.26, 9.2 g respectively). Moreover, the water relative content (65.69%) increased compared to the other treatments and with control (46.71%), proline concentration (0.55 mg/g) compared to the control (0.25 mg/g), in total soluble sugars concentration (0.57 mg/g), and in the nitrogen, phosphorus and potassium content of leaves (2.9, 0.19, 0.6% on respectively) compared to the non-coefficient control (2, 0.16 0.3% respectively). On the other side, control plant resulted in highest plant height (31.31 cm).