The formation of artificial nitrogen-fixing symbioses with rape (Brassica napus var. napus) plants in nonsterile soil

The treatment of rape plants grown in nonsterile soil with 2,4-dichlorophen oxyacetic acid (auxin-like growth-promoting substance) or their inoculation with the bacterial association Micrococcus sp. + Rhodococcus sp. and/or wi th the mixed nitrogen-fixing culture Azotobacter nigricans + Bacillus sp. l ed to the formation of paranodules on the rape roots. The introduced bacter ia were detected both in the intercellular space and inside the cells of th e paranodules and the rape roots. The nitrogen-fixing activity of the paran odulated plants was two times higher than that of the inoculated plants lac king paranodules and five times higher than that of the control (i.e., not inoculated) plants. The paranodulation led to a 40% increase in the crop yi eld of rape plants and provided for a statistically significant increase in the total nitrogen as well as protein nitrogen contents of the plants.