Helal Ragab Moussa and Mohamed Abd El-Rahman EL-Galad( 2014). comparative Response of Salt Tolerant and Salt Sensitive Maize (Zea mays L.) Cultivars to Silicon European Journal of Academic Essays 2 (1): 1-5, 2014
Abstract: Salinity stress is one of the most devastating stressful environments for plant growth and production. Two Zea mays cultivars, salt sensitive (Trihybrid 321) and salt tolerant (Giza 2), were grown in a complete nutrient solution in a growth room, to investigate the effect of silicon treatment, as Na2SiO3 (2.5 mM) on plants grown at two levels of salinity, 0.0 (Control), 150 mM of NaCl (S) which are equivalent to 15.5 dS m-1, and supplied to the nutrient solution. Maize plants (Giza 2 and Trihybrid 321) grown at 15.5 dS m-1 show a decreased in the chlorophyll (a+b), carotenoids, total protein contents, transpiration rate, relative water content (RWC), enzyme activity of ribulose-1,5-bisphosphate-carboxylase/oxygenase (RuBPCase), photosynthetic activity (14CO2-assimilation) and macronutrient level (N, P, and K) as compared to the control plants. The results indicated that silicon (Si) treatment at 2.5 mM partially offset the negative impacts and increased tolerance of maize (Giza 2 and Trihybrid 321) to salinity stress by enhancing the above parameters. In contrast, salt stressed maize plants considerably increased proline content, Na+ and Clˉ levels, H2O2, malondialdehyde (MDA), and electrolyte leakage (EL). Application of silicon (2.5 mM) decreased significantly these parameters as compared to salt stressed maize plants. Salt tolerant (Giza 2), treated with silicon at 2.5 mM showed better performance than salt sensitive (Trihybrid 321). Salt tolerant (Giza 2), exhibited lower accumulation of Na+ and Clˉ levels, H2O2, MDA, and EL more than salt sensitive (Trihybrid 321). Overall, exogenously applied Si was found beneficial for improving salt tolerance of maize plants.
Keywords: (Chlorophyll, salinity stress, photosynthetic activity, 14CO2-fixation.)
