Amelioration Of Flooding Stress Of Wheat Plants By Pseudomonas sp. Inoculation And (Or) Exogenous Ascorbic Acid Application

Abstract

The experiments included in this study were carried out during the convenient seasons of the years 2012-2013. The study was done to investigate the effect of deleterious effects of water logging (150% and 200% field capacity (F.C)) on growth and some physiological changes of wheat (Triticum aestivum L.) local cultivar grown in pot experiments.

     The study also investigated the effect of Pseudomonas sp. inoculation and (or) Ascerbic acid (AsA) foliar application on growth and some metabolic activities of wheat grown under such water-stress conditions. Pot experiments were conducted in the greenhouse of the botanical garden of the Faculty of Natural Resources, Omar El-Mukhtar University. 

     In pot-experiments wheat plant (Triticun aestivum L.) tolerated water flooding stress up to 2.0 field capacity (F.C.) level. Plant growth parameters (length, leaf-area, pigments, fresh and dry weight) were decreased by increasing water stress level. Pseudomonas inoculation and (or) ascorbic acid (1 mM) foliar application significantly enhanced growth parameters of wheat grown at different levels of water flooding stress. Pseudomonas inoculation increased the height of wheat seedlings by 16.1%, 16.0% and 7.1% as compared with the absolute control at 1, 1  and 2 field-capacity, respectively. Pseudomonas inoculation or ascorbic acid application enhanced the accumulation of shoot and root soluble carbohydrates up to 3 and five time at 2 field capacity. Pseudomonas inoculation and (or) ascorbic acid application increased wheat shoot and root crude-protein as compared with the corresponding control treatments. Water flooding decreased the accumulation of Na+, K+ and P+3 in wheat tissues, however, bacterization and (or) ascorbic acid significantly stimulated K+, P+3 but not Na+ accumulation in wheat shoot system as compared with control plants. Hydrogen peroxide (H2O2) accumulation in wheat root-system was at high levels by elevating water-stress. However, the lowest values of H2O2 was recorded by bacterization and (or) ascorbic acid application at 2 F.C. level of water-stress. Individual amino-acids increased in plants exposed to 2 field capacity compared with control plants. The amino-acid Proline was recorded in higher concentrations with ascorbic acid or when it was applied with Pseudomonas in mixed treatments at 2 field-capacity level.