Assessment of Response to Drought and Salinity Stresses of Barley (Hordeum vulgare L.) Mutants

Eight barley mutants (M-K 23, M-K 25, M-K 35, M-K 55, M-K 63, M-Q 54 and M-Q 76), two parents (Kaya and Quantum) and two checks (Chevron, salt sensitive and CM 67, salt tolerant) were grown in order to assess of response to drought and salinity in drought and saline (150 mol m−3 NaCl + 7.7 mol m−3 CaCl2) treatments. Net photosynthesis (μmol−2 s−1), stomatal conductance (mmol m−2 s−1) and transpiration rates (mmol m−2 s−1) were measured at the beginning of the flowering stage. Generally, salinity and drought negatively and severely affected net photosynthesis, transpiration rate and stomatal conductance of genotypes. From mutants, M-K 25 had the highest photosynthetic activity in drought; similarly M-K 63 had the highest photosynthetic activity in the external saline treatments. For ion analysis, the youngest fully-emerged leaf was used and measured chloride, sodium and potassium measured. Chloride accumulation in the leaves was generally higher in drought and saline treatments than control plants. Also, potassium concentration remained high in both treatments. Sodium accumulation, however, was slightly higher in drought than untreated control except for M-K 35 and M-K 55. Chloride concentration in M-Q 54 was the lowest among the genotypes in salinity condition. Quantum, M-Q 54 and M-Q 76 had the lowest sodium concentrations, while Kaya had the highest concentration in the saline treatment. In drought treatment, M-Q 54 had the highest potassium concentration, but CM 67 was the highest in saline treatment. Different responses to drought and salinity were found among the barley mutants.