Non-rhizobial peanut nodule bacteria promote maize (Zea mays L.) and peanut (Arachis hypogaea L.) growth in a simulated crop rotation system

The term “Plant Growth Promoting Bacteria” or PGPB designates a diverse group of prokaryotic microorganisms that can increase plant growth by diverse mechanisms. Some PGPB are capable of colonizing root inner tissues and constitute endophytic populations. Incorporation of these microorganisms into agricultural practices may constitute a valid alternative to increase crop productivity in a sustainable and environmentally friendly production scheme, reducing the application of agrochemicals. In a previous work, we described the characterization of bacteria belonging to Pseudomonas, Enterobacter and Klebsiella obtained from surface sterilized peanut nodules. In addition, we showed that some of these isolates were able to promote several peanut growth and symbiotic parameters. Bounded to the results from this particular study, and considering their potential ability to interact with different plant species, in this work we assessed the effects of their inoculation in maize (Zea mays L.) under controlled conditions. Furthermore, we analyzed growth promotion in a simulated peanut-maize crop rotation system. Finally, we determined the plant growth promoting (PGP) properties present in the isolates. Results indicated that all bacteria are able to significantly promote maize and peanut growth, and that they also displayed plant growth promotion activity in maize growing in a peanut-maize crop rotation sequence.