Effect of Se application on photosynthesis, osmolytes and water relations in two durum wheat (Triticum durum L.) genotypes under drought stress

Effect of Se (as Na2SeO4 at final concentration of 10 μg l^-1) was studied in two durum wheat (Triticum durum L.) genotypes in perlite under drought conditions. Se treatment increased slightly biomass of both genotypes under drought but not under control conditions. Photosynthetic rate was depressed by drought while increased by Se treatments in both genotypes up to 2.3 fold. However, transpirational water loss was also enhanced in Se-treated plants under both wellwatered and drought conditions. Se application resulted in higher concentrations of soluble proteins and free α-amino acids under drought conditions, but not proline. Our results indicated that Se application improves some physiological parameters such as photosynthesis, accumulation of osmolyes and water use efficiency but did not change significantly plants biomass or water relation parameters.