Introduction of morpho-physiological and biochemical markers to select salt-tolerant wheat (Triticum aestivum) genotypes under salinity stress.

Abstract

As a strategic crop, wheat is important to the world’s food supply. Salinity is a major threat to the food supply in the whole world and Iran. The research was carried out for identifying morpho-physiological and biochemical markers to select salt-tolerant wheat genotypes. The research was done on two salt-tolerant (Pishgam) and susceptible (Shahryar) bread wheat cultivars under saline conditions (250 mM NaCl). The results showed a high genetic diversity for most traits. The traits of harvest index, root-to-shoot dry weight ratio, root dry weight, plant height, potassium-to-sodium ion ratio, total protein, superoxide dismutase, catalase, peroxidase, and total carbohydrates showed the highest alignment with increasing grain yield under salt stress conditions. The traits of potassium ion accumulation (K+), superoxidase dismutase (SOD), proline (Pr), and relative water content (RWC) were entered into the regression model, as the most important traits affecting grain yield under salinity conditions, respectively. According to the results, it is possible to suggest two groups of markers to select salt-tolerant genotypes. The first group includes some morpho-physiological markers namely a high amount of harvest index, main spike weight, relative water content, water consumption, root-to-shoot dry weight ratio, total carbohydrates, proline, and root dry weight; and the second group includes the ionic and biochemical markers namely a high amount of K+ accumulation, K+/Na+ accumulation ratio, SOD, catalase, peroxidase, and a low amount of Na+ accumulation, malondialdehyde, and hydrogen peroxide. Therefore, the above-introduced markers can be useful indicators to select salt-tolerance genotypes in future wheat breeding programs.

Keywords

• potassium ion
• sodium ion
• catalase
• superoxidase dismutase
• hydrogen peroxidase
• proline