Response of Some Physiological Traits in Maize Cultivars to Salinity Stress

Salinity stress is one of the most important abiotic stresses that effects on many agronomic, nutritional, physiological, and biochemical processes of crops.

To assess response of fresh weight, osmolytes, pigment contents, RWC, Na+, and K+ levels in maize cultivars, a factorial experiment based on completely randomize design with three replications under greenhouse conditions at the Faculty of Agriculture and Natural Resources-Moghan was carried out. The first factors were six maize cultivars as SC647, TWC647, SC704, SC705, SC706 and SC715, and the second factors were three levels of salinity stress as 0, 100 and 200 mM NaCl.

The results indicated that NaCl stress significantly reduced fresh weight, photosynthetic pigment, and RWC, but significantly increased glycine betaine and proline, Na+, and K+ contents. There were significant differences between maize cultivars in terms of fresh weight, osmolytes, pigment contents, RWC, Na+, and K+ levels. The applied salt stress as 100 and 200 mM NaCl reduced fresh weight about 10 and 18 percent, respectively.  Significant correlations were observed between fresh weight and Na+/K+ ratio, and also significant correlations were observed between osmolytes, pigment contents, and Na+, and K+ levels. TWC647 cultivar with high fresh weight, K+, glycine betaine, and proline contents was salt-tolerance.

The results indicated that salt-tolerance maize cultivars via increase osmolytes, and regulation between Na+, and K+ ions can tolerate salinity stress damage in maize plant.