MORPHO-PHYSIOLOGICAL RESPONSE OF HYBRID MAIZE (Zea mays L.) TO SALT STRESS IN COMBINATION WITH EXOGENOUS CALCIUM APPLICATIONS

Maize, the third most important cereal crop around the globe, is hampered by devastating abiotic factors including salt stress. Calcium is known to increase plant tolerance to biotic and abiotic stresses by influencing physiological processes. The current study was carried out to investigate the genetic variation of maize hybrids against salt stress in combination with exogenous application of calcium (Ca2+) in a hydroponic culture. Three levels of salinity, each with NaCl (0 mM, 75 mM, and 150 mM) and Ca2+ (0 mM, 2.5 mM, 5 mM) were applied to maize hybrids in three replications and data were recorded for key morpho-physiological traits. The results showed that all concentrations of NaCl significantly affect the maize hybrids with Sarhad White Azad Jammu Kashmir (SWAJ 6,7) and Syngenta 8441 being the least affected by both 75 mM and 150 mM NaCl concentrations. The exogenous application of 2.5 mM Ca-2 + with 75 mM salt concentration showed significant effects on all morpho-physiological traits of maize hybrids. Better growth performance, maintenance of nutrient contents, lower accumulation of toxic sodium ions and lower Na+/ K+ in SWAJ6,7 and Syngenta 8441 indicate that these maize hybrids are more tolerant to salinity stress than the others under study.