Contribution to assessment of resistance degree to water stress (drought and water flooding) at barley (Hordeum vulgare L.) and tall fescue (Festuca arundinacea Schreb.)
1994
Ben Naceur, M.
The ability of barley and tall fescue to resist water stress (drought and flooding) was assessed by a study of plant water relations, cell membrane integrity, activity of phosphatasic enzymes and adaptation of root systems. Under drought stress, barley maintained an adequate leaf water potential, a high relative water content and maintained a low but continuous rate of transpiration. As a result, growth of barley was less affected by drought stress. Tall fescue was more sensitive to droughting, and grew poorly under these conditions. The integrity of barley cell membranes was less affected by drought or polyethylene glycol (PEG), induced osmotic shock than was the case for tall fescue. When tall fescue was subject to flooding, aerenchyma formed in the root cortex, enabling oxygen to diffuse into the rooting zone, thus reducing the incidence of anaerobic conditions. Changes in water supply regimes were found to induce characteristic changes in plant acid phosphatases. Those species or varieties, with greater sensitivity to water stress showed increases in activity under stress conditions. The relationships between the above parameters and water stress were used to rank Tunisian barley cultivars with respect to drought resistance.
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