Comparative study of the effect of moderate and strong sodium chloride salinization on growth and photosynthetic apparatus of cultivated cereals

Abstract

In a controlled environment, the effect of moderate (100 mM) and strong (200 mM) sodium chloride salinity on seed germination, seedling growth and the state of the photosynthetic apparatus (PSA) of barley (Hordeum vulgare L.) varieties Nur and wheat (Triticum aestivum L.) varieties Zlata was studied. It was found that with moderate salinization, the seeds of both species successfully germinated, but the growth of shoots and the accumulation of aboveground biomass were inhibited, which was partly due to a slowdown in the rate of photosynthesis. With strong salinity, distinct interspecific differences were observed in the response of plants. In particular, the number of germinated seeds decreased in barley, while in wheat it remained at the control level. In barley, shoot growth was inhibited to a greater extent, whereas in wheat, the accumulation of aboveground biomass was. The content of pigments in barley plants decreased, and the content of wheat increased. At the same time, stomatal conductivity decreased in both species and the rate of photosynthesis slowed down. It is concluded that based on the energy of germination and germination of seeds, it is possible to determine the salt resistance of species only to a high level of salinity (200 mM NaCl). Morphometric indicators of shoot growth make it possible to assess the resistance of plants to salinity already at lower salt concentrations (100 mM NaCl). For a more accurate comparative assessment of the salt resistance of species (varieties, varietals, genotypes) of cereals, not one, but several indicators should be used, reflecting not only the growth potential of plants, but also photosynthetic activity.