Exogenous Application of Salicylic Acid and Glycine Betaine as Tools to Enhance Biomass and Tolerance of Potato Cultivars

This pot experiment was aimed at characterization of agro-physiological responses of potato to water deficit and exogenously application of salicylic acid (SA) and glycine betaine (GB). Four potato cultivars, Spirit, Born, Arinda and Banba, were exposed to two irrigation regimes (30 and 60% depletion of available soil water) and two levels of both SA (0.5 and 1.0 mM) and GB application (1.0 and 2.0 mM) in addition to the control (0.0 mM SA and GB). Activities of ascorbate peroxidase (APX), superoxide dismutase (SOD), total antioxidant capacity (TAC), ion leakage (IL), fluorescence chlorophyll (Fv/Fm), chlorophyll pigments, root dry mass (RDM) and plant dry mass (PDM) were measured. Water deficiency resulted in significant effects on all characteristics. Antioxidant enzymes and IL increased, but the other characteristics decreased significantly with water deficit. Tolerant cultivars (Spirit and Born) revealed higher activity of SOD enzyme, chlorophyll content, PDM and lower IL than non-tolerant cultivars (Arinda and Banba). This investigation has been able to provide evidence that SA and GB affected antioxidant enzymes and increased chlorophyll pigments and PDM. The range of the increases seemed greater when potato cultivars were grown under water deficit circumstances. PDM increased by increasing SA and GB levels. This led to the supposition that injurious effects on potato cultivars due to water deficit could be relieved by SA and GB.