Salt Tolerance Assessment of Different Tomato Varieties at the Seedling Stage

The identification of reliable physiological and biochemical indicators for assessing tomato salt tolerance can increase the efficiency of plant breeding to create new varieties and lines. The purpose of our study was to identify available physiological and biochemical relevant characteristics for assessing the sensitivity to sodium chloride salinity of different tomato genotypes at the seedling stage. A complex analysis was carried out based on indicators such as biomass growth, water content of plant tissues, content of readily soluble salts, sodium and chlorine ions, photosynthetic pigments, carotenoids, phenolic compounds and flavonoids. Additionally, the stomata area of the upper and lower epidermis was taken into account. The comprehensive assessment carried out made it possible to reliably divide the eight studied tomato varieties into two groups: sensitive (Belyij Naliv, Geya, YaLF, Paradigma) and tolerant (Recordsmen, Yuryevskij, Bych’e Serdce, Astrakhanskij). Tomato genotypes that can be classified as sensitive (in order of increasing sensitivity to high concentrations of NaCl (150 mM)) were Belyij Naliv > Geya > YaLF ≥ Paradigma. Tomato genotypes that can be classified as resistant to salt stress (in order of increasing tolerance to high concentrations of NaCl (150 mM)) were Recordsmen < Yuryevskij < Bych’e Serdce < Astrakhanskij. The advisability of only using complex physiological and biochemical indicators to obtain relevant assessments for salinity tolerance at the early stages of tomato plant development has been demonstrated.