FIGURE 3.

Suggested steps for developing elite rhizobial inoculants from native strains. (A) Perform physical, chemical, and microbiological soil analysis. Although we recognize the importance of full microbiome interactions with the plant, this review will focus on rhizobial inoculants. (B) Trapping assays using the desired host genotype and soil of interest, followed by the identification and characterisation of native rhizobia [i.e., Most probable number (MPN) – and strain-specific fingerprints], and preparation of rhizobial isolate libraries. (C) Multi-strain inoculations in the plant genotype using the same soil from which strains where isolated. Perform simultaneous assessment of rhizobial competitiveness and N₂-effectiveness, followed by the identification of elite strains by next-generation sequencing (NGS). Analysis of multicomponent interaction studies using a multidisciplinary approach and final scaling-up and formulation based on the elite strains with best performance in the soil under study for a tailored inoculant.