Features of <i>Melica virgata</i> (Poaceae) seed germination in natural drought stress

The paper studies mechanisms of adaptation of the rare species Melica virgata Turcz. ex Trin for Eastern Transbaikalia to drought at the initial stages of ontogenesis. The species is listed in the Red Data Book of Trans-Baikal Territory and has the first conservation status category (Endangered). M. virgata occurs in special phytocenoses on the territory of Eastern Transbaikalia, being in such microclimatic conditions that correspond to its xeromesophytic nature. This cereal is characterized by seed reproduction. Researches of seed germination in conditions of physiological drought, caused by the presence of osmotic, have shown the ability of M. virgata seeds to germinate in a wide range of moisture availability, but growth processes with an increase in osmotic pressure are strongly suppressed. The ability to germinate in conditions of physiological drought may be associated with the exchange of free amino acids. The seeds of cereals were dominated by acidic amino acids and their amides, which are substrates for the formation of other amino acids, nucleotides, as well as after deamination reactions, carbohydrates and lipid components. The intensity of accumulation of free amino acids in water deficit can vary due to the use of these amino acids for the synthesis of substances with osmoregulatory properties. The rapid transition to growth processes in this cereal may be associated with the mobilization of prolamins and glutelins on the first day of germination.