Assessment of the Adaptive Capacity of Regenerative and Original Oat Genotypes to Soil Stressors

The studies were conducted with the purpose of comparative analysis of the response to soil stressors of the original genotypes (line 2h15) and regenerative forms (RA, RA_Al, RA_Mn, RA_Cd) of oats as part of the efficiency assessment of the applied cell selection schemes. In a vegetation experiment, the effect of the following soil stressors on plants was studied: increased acidity (pH 4.3) and toxicity of manganese (65.2 mg/kg, pH = 5.2) and cadmium (2.87 mg/kg, pH 5.2) ions. The Arkhan variety was used as a standard. Soil with a neutral pH (7.2) served as a control. The regenerants were preliminarily obtained in vitro on artificial media without stress (RA) and with selective agents: aluminum acidity (RA_Al), increased content of Mn²⁺ (RA_Mn) and Cd²⁺ (RA_Cd). On soil with stressors, the content of pigments in the leaves of the regenerants increased by 1.4–1.6 times compared to the original line. In the control, the differences between RA and the original line were insignificant. All regenerative lines, regardless of growing conditions, were characterized by a significantly lower level of polyphenols in grain (11.2–12.4 mg/g dry weight) compared to the original line and the standard: by 1.2–1.3 times. Against the backgrounds with artificial introduction of metals, we noted the excess of manganese content in grain in RA_Mn (256.1 mg/kg) by 1.7 times and the absence of differences in the amount of cadmium with RA_Cd (1.82–1.67 mg/kg) compared to the initial line. Against the control background, RA and the initial line were significantly inferior to the standard in grain weight per plant: regenerants by 1.29 g, initial line by 1.38 g, and standard by 1.65 g. With an increase in acidity and cadmium content, all genotypes reduced productivity relative to the control: the least in regenerants, by 1.6 and 1.4 times, respectively. In the initial line, it decreased by 2.8 and 2 times, while in the standard by 2.4 and 1.9 times.