Эффективность штаммов Bradyrhizobium yaponicum на фоне местных популяций ризобий сои

Specific nodule bacteria that establish a symbiotic relationship with plants play a significant role in achieving high soybeans yields. The paper presents the results of investigations concerning the application of Bradyrhizobium japonicum active strains for soybean inoculation against the background of local populations of soybean rhizobia. The following was investigated: B. japonicum strains 46 and M8; antisera 46, M8, 634b and KV11; and soybean plants of Ustya variety. Symbiotic properties and competitive ability of strains of soybean nodule bacteria were studied under the conditions of greenhouse and field trials within different populations of specific rhizobia. We studied the peculiarities of interaction of B. japonicum active strains 46 and B. japonicum active strains М8 with soybeans against the background of local populations of specific rhizobia. It is shown that the absolute domination of introduced strain in nodules is not always crucial for increasing crop yields. Against the background of soil populations of nodule bacteria the most effective symbiotic soybean systems are formed not by one, but by several complementary parts although serologically different rhizobia strains of one species. It is found that the B. japonicum 46 is the most active symbiotic nitrogen fixer. As a biological agent of Rizobofit this strain is able to stand competition with monoand multi-strain local populations of soybean rhizobia and to provide constant increase of above-ground plant herbage by 12.9%-18.5% and bean harvest by 17.0% as compared to the control. A patent of Ukraine for B. japonicum 46 was obtained and it is proposed to be used in the production of biological fertilizers to increase soybean yields.