Abstract

This paper investigates the dependence of protein and fat content of soybean cultivars with various genetic origins on growing conditions and cultivar genotypes. We examined seeds of 11 cultivars and four soybean cultivar samples differing in the duration of the vegetation period, grown on seasonally frozen soils of Priamurye in 2017–2019, which corresponded to parameters of hydrothermal resources for cultivation in the southern agricultural zone of Amur oblast. Weather and climatic conditions during the years of the experiment differed significantly by the sum of active temperatures during vegetation periods and the precipitation distribution. In terms of the sum of active temperatures, 2017 and 2018 were the most favorable, when the excess of the relative norm was 135 and 157°С, respectively. An excess amount of precipitation was characteristic of 2019, which contributed to the active outflow of nutrients into seeds. We determined coefficients of variation (CV) of the “protein content” trait in soybean seeds of Russian and foreign-bred cultivars, which confirmed the dependence of this indicator on the growing conditions to a greater extent than the cultivar genotype. The coefficient of variation in soybean seeds of Russian soybean cultivars varied from 0.28 to 5.87% depending on the conditions of the year and from 2.11 to 3.80% depending on the cultivar. In foreign cultivars, it varied from 0.55 to 5.23% and from 3.79 to 4.63%, respectively. The highest stability in protein content in soybean seeds, depending on weather and climatic conditions, was revealed in cultivars of early maturing groups. The best cultivar in terms of this feature among Russian cultivars was Topaz, and it was the Chinese cultivar Hei 11-1170 among the foreign ones. We observed high protein content in seeds of Russian cultivars Sentyabrinka and Statnaya (42.3 and 43.0%, respectively). Among foreign cultivars, high protein content in seeds was found in the Chinese cultivar Hei 05-1031, 43.2%. Canadian soybean cultivars Maxus, Saska, and Kanata, and the American cultivar sample AD 12M had long vegetation periods, which resulted in frost seeds. The interdependence of protein and fat content in seeds of all soybean cultivars was shown.