Abstract
A search for markers of epigenetic variability in spring common wheat form Genotroph-1, obtained after the treatment of seeds and growing plants of spring common wheat cultivar Kazakhstanskaya-126 with nicotinic acid of innate origin (0.1–0.01% water solutions), and in a winter wheat line Gostianum-88 along with a common wheat cultivar Alem obtained on the basis of Genotroph-1 was conducted under laboratory conditions. The possibility of using isoenzymes as markers for studying variability induced by natural nicotinic acid with high frequency was demonstrated. The marker enzyme glutamate oxaloacetate transaminase-2, by which modified plants and lines obtained on the basis of these plants differ from the original cultivar, was identified.