Adaptation parameters of soybean cultivars in the Steppe Zone of Primorsky Krai

High profitability and the unique biochemical composition of seeds play an essential role in soybean production. Climatic and edaphic conditions of the cultivation area have a significant impact on the level of nutrient accumulation in soybean seeds. The research goal was to study promising soybean cultivars in the contrasting conditions of Primorsky Krai for their adaptability based on the accumulation level of protein in seeds. Seventeen promising soybean varieties were studied according to generally accepted methodology at Federal Scientific Center of Agricultural Biotechnology of the Far East named after A.K. Chaika in 2021–2024 (Primorsky kray, Russia). The research evaluated the soybean cultivars for a number of adaptability parameters and identified soybean genotypes with high adaptability. Primorskaya 1551 (2.75 t/ha), Primorskaya 1666 (2.82 t/ha), and Primorskaya 1672 (2.93 t/ha) had high stable yield over the four years of the research. The environmental conditions of 2022 and 2024 were favorable for accumulation of protein in soybean seeds. Cultivars Primorskaya 1673, Primorskaya 1677, and Primorskaya 1666 were highly adaptable. A high level of stress resistance was observed in cultivars Primorskaya 1669 (–3.9), Primorskaya 1668 (–4.1), and Primorskaya 1671 (–4.2). High plasticity was characteristic of (О = 18.4…20.7) Primorskaya 1595, Primorskaya 1664, Primorskaya 1667, Primorskaya 1669, and Primorskaya 1671. The level of variety stability in Primorskaya 1669 and Primorskaya 1595 acceded the standard by 18.0 and 20.6 %, respectively. High ecological plasticity was noted in Primorskaya 1666, Primorskaya 1673, and Primorskaya 1677 (EPI = 1.03). Based on a complex of adaptability parameters, the research selected soybean genotypes able to accumulate relatively high protein levels in seeds under the growing conditions of the steppe zone of Primorsky Krai. The highest parameter values of adaptability were characteristic of soybean cultivars Primorskaya 1677 (37) and Primorskaya 1667 (42).