Effect of Salicylic Acid and Ultraviolet Rays on Vegetative Growth Characteristics of Rosmarinus officinalis L. in Vitro

Abstract

This study was carried out in the plant tissue culture laboratory of the College of Agriculture - University of Karbala for the period from 2021 to 2022. The study included the use of plant tissue culture technique to obtain vegetative branches of rosemary using physical and chemical stimuli as well as plant growth regulators, the experiment was done by cultivating sterile branches tips With a length of 2 cm on MS medium prepared with different concentrations (0, 10, 20, 30) mg.L^-1 SA, Then the cultivated plants were exposed to ultraviolet rays at different intervals (10, 20) minutes for each concentration of SA. The results of the study showed that the concentration of 10 mg.L^-1SA achieved the highest rate in the number and length of branches that reached (7.45 branches.Plant^-1, 3.63 cm) respectively, while the concentration of 20 mg.L^-1 achieved the highest average for the number of leaves and the fresh and dry weight of the shoot, and the average concentration of chlorophyll and carbohydrates in the shoot reached (16.86 leaves.plant^-1, 3424 mg.gm^-1, 2373 mg.gm^-1, 3.57 and 4.28 mg.gm^-1) respectively, and the effect of UV rays at 20 minute exceeded in achieving the highest average of the measured traits, which included the number and length of branches, number of leaves, fresh and dry weight of the shoot, as well as the average concentration of chlorophyll and carbohydrates in the shoot (7.24 branches.plant^-1, 4.04 cm, 16.89 leaves.plant^-1, 3374 mg.gm^-1, 2141 mg.gm^-1, 3.67 and 4.32 mg.gm^-1) respectively, while the comparison treatment achieved the lowest rate It reached (3.59 branches.plant^-1, 2.39 cm, 14.21 leaves.plant^-1, 2810 mg, 1366 mg, 2.56 mg.gm^-1, 3.38 mg.gm^-1) respectively.