Results of the selection of pure cultures with economically useful properties from the Far Eastern natural populations of soybean rhizobia

Abstract

The studies were carried out in 2019–2020 at the All-Russian Soybean Research Institute in order to investigate the effectiveness of strains Bradyrhizobium japonicum (Jordan, 1982) and Sinorhizobium fredii (Scholla, Elkan, 1984), resistant to ammonium molybdate in the concentration of 10 g/l used for soybean seed (Glycine max (L.) Merr.) treatment. The objects of the studies were pure cultures of two soybean rhizobia species, soybean varieties were Evgeniya, Persona, Topaz, Kitrossa of the All-Russian Soybean Research Institute of soybean. The resistance of pure cultures of soybean rhizobia B. japonicum and S. fredii, stored in the laboratory collection of the All-Russian Research Institute of Soybean, to various doses of ammonium molybdate in the nutrient medium was studied under laboratory conditions. As a result, it was found that with an increase in the ammonium molybdate concentration in the nutrient medium up to 10 g/l, 66 % of pure cultures of B. japonicum and 9 % of S. fredii ceased their growth, strains of rhizobia resistant to an increased concentration of molybdenum salt in the medium were identified. The efficiency of the selected strains was studied in field experiments on the meadow chernozem-like soil of the Amur Region. Based on the results of two years of testing, promising strains of rhizobia – B. japonicum (ТМ-455, ТМ-469, BM-91, BD-14) and S. fredii (BB-49, TB-589 SB-38, SB-43, 071), which increase the seed productivity of the Amur soybean varieties by 0.07-0.4 t/ha were selected.