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Salinity Tolerance in Barley (Hordeum vulgare L.): Effects of
Varying NaCl, K+/Na+ AND NaHCO3 Levels
on Cultivars Differing in Tolerance
K. MAHMOOD*
Abstract:
Although barley (Hordeum vulgare L.) is regarded as salt tolerant
among crop plants, its growth and plant development is severely affected
by ionic and osmotic stresses in salt-affected soils. To elucidate the
tolerance mechanism, growth and ion uptake of three barley cultivars,
differing in salt tolerance, were examined under different levels of
NaCl, K+/Na+ and NaHCO3 in the root
medium. The cultivars differed greatly in their responses to varying
root medium conditions. Plant growth was more adversely affected by
NaHCO3 than NaCl. In general, biomass yields were comparable
under control and 100 mM NaCl. However, growth of all three cultivars
was significantly inhibited by NaHCO3 even at low
concentration (10 mM). Improved K+ supply in saline medium
increased K+ uptake and growth of less tolerant cultivars. K+
uptake was more adversely affected by NaHCO3 than NaCl
salinity. Selective K+ uptake and lower Cl- in
shoots seemed to be associated with the growth responses. K application
would help better growth of these cultivars on K-deficient saline-sodic
soils and under irrigation with poor quality water having high Residual
Sodium Carbonate (RSC) and/or Sodium Adsorption Ratio (SAR).
Nuclear
Institute for Agriculture and Biology (NIAB),
P.O. Box
128, Faisalabad, Pakistan.
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