Responses of two barley cultivars differing in their salt tolerance to moderate and high salinities and subsequent recovery

Abstract

Two barley (Hordeum vulgare L.) cultivars, Czech spring cv. Amulet and Syrian landrace Tadmor, were subject to different salinity treatments: 1) the NaCl concentration was gradually increased from 0 (the control) to either 100 (a moderate salt stress) or 300 mM NaCl (a high salt stress), 2) the NaCl concentration was increased directly either from 0 to 300 mM NaCl or from 100 to 300 mM NaCl, and 3) a recovery when all variants were transferred back to control conditions and cultivated for seven additional days before sampling. The following parameters were determined: water saturation deficit (WSD), osmotic potential (ψs), leaf proline content, maximum quantum yield of photosystem (PS) II photochemistry (measured as variable to maximum chlorophyll a fluorescence ratio, Fv/Fm), and relative accumulation of dehydrins (DHN). Both quantitative and qualitative differences in dehydrins were found between NaCl-treated Amulet and Tadmor. A principal component analysis (PCA) of all experiment data revealed a differential ability of Amulet and Tadmor to recover after the 300 mM NaCl treatments indicating better salt tolerance in Tadmor. Correlation analyses have shown statistically significant correlations between WSD, ψs, proline, and DHN.