Impact of Calcium Supplementation on Photosynthetic Pigments, Compatible Osmolytes Contents and Membrane Stability Index in Triticale (x Triticosecale Wittmack) Exposed to Salinity Stress

Abstract

In many areas, salinization is considered as one of the most serious dangers to environmental resources and human health. Calcium has a crucial role in plant resistance to salinity stress. In order to investigate the impact of calcium supplementation on photosynthetic pigments, compatible osmolytes contents and membrane stability index (MSI) in triticale (x Triticosecale Wittmack) exposed to salinity stress, an experiment as a completely randomized design with 3 replications in greenhouse condition (25 ± 2^°C, 35% relative humidity, 16-hour photoperiod) was conducted. The seeds were germinated in soil. One week old triticale seedlings (with two leaves) were imposed by 0, 50, 100 and 150 mmol L^-1 NaCl and 0, 6 and 10 mmol L^-1 CaCl₂ for 5 weeks and assayed for some morpho-physiological parameters including fresh weight (FW) and dry weight (DW) of shoot, photosynthetic pigments (chlorophyll (Chl) a and Chl b, total Chl and carotenoids (Car)) contents, proline and glycine betaine (GB) contents, soluble sugars and starch contents and MSI in leaves. Results showed that with incrementing salinity meaningfully decremented FW and DW of shoot, photosynthetic pigments, starch content and MSI while proline, GB and soluble sugars contents incremented in leaves. Calcium treatment meaningfully incremented FW and DW of shoot, photosynthetic pigments, starch content and MSI but caused a meaningful decline in proline, GB and soluble sugars contents in leaves. It can be concluded that calcium had exerted an ameliorative impact on triticale under salinity stress. Maximum ameliorative impact of calcium was observed in plants exposed to 6 mmol L^-1 CaCl₂.