Phenomics-based screening for salinity tolerance: a case study for the evaluation of the impact of salinity on growth of barley and faba bean

Phenomics-based screening for salinity tolerance: a case study for the evaluation of the impact of salinity on growth of barley and faba bean

Salinity reduces crop productivity in many agricultural areas, especially in arid and semi-arid regions. Growth is reduced by osmotic effects and ion-specific mechanisms. While Munns et al (1995) proposed a two-phase model of salt injury, where growth is initially reduced by osmotic stress and then by Na+ toxicity, it is currently difficult to assess the relative importance of the two mechanisms to yield reduction because they overlap. The objectives of this experiment were to evaluate the mechanisms of salt tolerance in barley and faba bean and to quantify the injury of seedlings suffered under NaCl stress. A factorial soil-based experiment examined the effect of different concentrations of NaCl (0, 25, 50, 75 and 100 mM) and concentrated macro-nutrient solution on the growth of two varieties of barley (Clipper and Sahara) and two varieties of faba bean (Cairo and Fiesta). These varieties were selected from previous screening experiments because of their differences in salt tolerance. The experiments were a completely randomised design with 6 or 5 replicates. Non-destructive and near-real-time measurements of plant growth were made during the experiment using a LemnaTec Scanalyzer®. Destructive harvests were used to measure Na+, K+ and Cl-concentration, organic compounds and leaf osmotic potentials. Gas exchange studies were made at different times using a LI-COR 6400 portable gas exchange system. Physiological analyses of these traits in relation to the different mechanisms of salt tolerance and their suitability as selection parameter will be discussed.

Poster presentation.