Biochemical Composition of Soybean Seeds of a Northern Ecotype Under Various Growing Conditions

The article presents the results of the analysis of the quality of soybean seeds of a northern ecotype under various growing conditions. The following varieties were studied: Svetlaya, Okskaya, Magev, M-134 and M-52. The highest protein content was observed in M-134. According to the mineral composition, no differences were found between varieties. However, in dry years, the phosphorus content in soybean seeds decreases. The specific weight of the easily soluble soybean seed protein fractions increased under the conditions which are favorable for symbiosis. The share of alkali-soluble fraction of protein increases under conditions which are not favorable for symbiosis. Under these conditions, the content of trypsin inhibitors also increases. The prevalence of the specific group of acidic and heterocyclic amino acids was observed. The amino acid composition of protein, depending on the matricular quality of seeds, slightly differed by the varieties, although the seed protein of the upper nodes was more saturated with essential amino acids than the lower ones. There were no significant differences in the amino acid composition of seed protein. However, there was an increase in the amount of essential amino acids in two-seed and three-seed beans as compared with oneand four-seed ones. In general, the varieties of a northern ecotype are characterized by a high content of essential amino acids, a higher concentration of palmitic acid, B vitamins, and a low amount of trypsin inhibitors.