EVALUATION AND CHARACTERIZATION OF GENETIC VARIATION IN MAIZE (Zea mays L.) FOR SALINITY TOLERANCE

Salinity is an important agricultural problem that reduces crop production around the world. Maize (Zea mays L.) is an important cereal crop and is not considered tolerant to salinity. The present study was conducted to study the response of different maize genotypes to salinity and to explore the mechanisms of their differential response to salinity. This genotypic variation for salt tolerance in maize was examined in solution culture. Seven days old seedlings of six maize genotypes were transplanted in half strength Hoagland nutrient solution with two treatments (control, 75 mM NaCl) and three replications in completely randomized statistical arrangement. After 30 days of salinity development, the plants were harvested and data for shoot fresh weight, root fresh weight, shoot dry weight root dry weight, shoot length and root length were recorded. Na^+ and K^+ contents were determined from tissue sap and K^+: Na^+ ratio was computed. All the growth parameters of different maize genotypes were significantly reduced due to salinity. The genotypic variation for salt tolerance was also observed among the maize genotypes used in this study. The genotype EV-78 was ranked as salt tolerant genotype because it produced the maximum shoot biomass (6.33 g) and maintained higher K^+: Na^+ ratio (1.5) where as KS-64 was ranked as salt sensitive genotype as it produced the minimum shoot biomass (3.36 g) and could maintain the lowest K^+: Na^+ (0.86) ratio under salinity.