The Effect of Salicylic Acid on Hydrogen Peroxide Induced Stress in <i>Allium cepa </i>L.

The present experimental work was related to determine the effect of salicylic acid on Onion bulb (Allium cepa L.) under Hydrogen peroxide stress. There are different types of reactive species such as hydrogen peroxide that contain free radicals are atoms which comes from oxygen. The color of hydrogen peroxide is colorless which have resembled to the color of water. Strong antioxidants were found in hydrogen peroxide that is used for industrial biotechnology and effluents process. The different physiological parameters were determined such as shoot, root length and weight and also total phenolic, antioxidant, and photosynthetic pigments contents. Application of salicylic acid reduced the negative effect of hydrogen peroxide stress and significantly enhance the morphological and physiological parameters i.e. shoot, root weight and length. The photosynthetic contents are higher only in hydrogen peroxide as a compared to combined treatments of salicylic acid and hydrogen peroxide, which increase the phenolic and antioxidant power and biomass in onion bulb. The different concentration of hydrogen peroxide like (0.5%,1% & 1.5%) had positive effect on onion bulb but with high concentration (2%, 2.5% & 3%) had negative effect on onion bulb and therefore salicylic acid (3mg/L) mitigated harmful effect of hydrogen peroxide.