COMPETITIVE SEEDLING GROWTH AND K+/Na+ RATIO IN DIFFERENT MAIZE (ZEA MAYS L.) HYBRIDS UNDER SALINITY STRESS

Genetic variation for salt tolerance was assessed in maize (Zea mays L.) hybrids using solution-culture technique. The study was conducted in gravel Culture exposed to three salinity levels (0, 50 and 100 mM NaCl). Seven days old maize seedlings were transplanted in gravel containing 1/2 strength Hoagland nutrient Solutions and salinized with common salt (NaCl). The experiment wits conducted in the rain protected wire house of Plant Stress physiology Laboratory of NIAB Faisalabad, Pakistan. Ten maize hybrids were used for mass screening against three salinity levels. Substantial variations were observed in the root, shoot length and biomass of different cultivars at different salinity levels. The leaf sample analysed for inorganic osmolytes (sodium and potassium) showed that hybrid pioneer 32B33 and pioneer 30Y87 have high K+/Na+ ratio. From this study it was concluded that hybrids with high biomass, root shoot fresh weight and K+/Na+ ratio are salt tolerant.