Inconsistency in the environment exposes plants to various abiotic stresses. This results in damage of a plant’s cellular components due to excessive accumulation of unstable reactive oxygen. Besides, it also disrupts enzymatic/non-enzymatic detoxification mechanisms in plants making them more sensitive. Salinity is one such abiotic stress which disrupts regular physiological mechanisms in plants. In this study, we examined the effects of salinity using NaCl in four different genotypes of Gerbera jamesonii cv Bolus, an important ornamental plant of family Compositae. We hypothesized that, upon treatment with NaCl (50, 100, 150 200mM concentration), alterations in the morphological features along with elevated levels of H2O2, MDA, proline, and degradation of chlorophyll will be observed. The enzymatic antioxidant defenses were also hypothesized to differ among genotypes based on their level of tolerance. These parameters were monitored on the 5th and 20th day of NaCl treatment and results were recorded. The observations suggest that 1. the Lattara genotype of Gerbera is sensitive to NaCl and 2. Faith is tolerant, while 3. Alcatras and Basic are moderately tolerant. These findings accompanied by further research on the physiological parameters responsible for attaining salinity tolerance may help in developing salt-tolerant varieties in Gerbera. Future studies on decoding molecular networks associated with the antioxidative defense system in Gerbera can help improve breeding and create novel germplasm in various ornamentally important plants besides Gerbera.

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The present study was carried out to investigate the role of spermidine (Spd) in alleviating salinity stress in an ornamental plant, Gerbera jamesonii cv Bolus ex Hook. f. From our laboratory studies, we could establish that G. jamesonii plants grown in a polyhouse are hugely exposed to salts due to repeated fertigation and differ in their sensitivity toward salt stress. In the present study, we have assessed changes in the salinity tolerance levels across G. jamesonii genotypes when treated with exogenous supplementation of Spd. The sodium chloride (NaCl) sensitive (white), moderately sensitive (pink), and tolerant (yellow) G. jamesonii varieties were subjected to 200 mM NaCl treatment followed by an exogenous foliar spray of Spd (1.0 mM). Our findings revealed that Spd treatment increased leaf growth, soluble protein, proline, chlorophyll content and lowered lipid peroxidation, and hydrogen peroxide accumulation. Enhanced enzyme activities of superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase following treatment with Spd suggest its role in conferring salt tolerance in G. jamesonii genotypes. Supplementation of 1.0 mM Spd has drastically improved efficiency of photosynthesis by minimizing salt stress initiated cellular injury by scavenging highly reactive oxygen radicals.