Endophytic bacteria promote growth of the medicinal legume Clitoria ternatea L. by chemotactic activity

Part of the native root nodule endophytic microflora referring to members of the genera Proteobacteria and Sphingobacteria were used to test their bioefficacy as seed biopriming. These were quantified for their plant growth promoting (PGP) attributes such as IAA production, P and K-solubilization and ACC deaminase production. Results showed that significantly highest IAA was produced by E. hormaechi RCT10. The highest P-solubilization was observed with S. maltophila RCT31 it was solubilizing all the substrate tri-calcium phosphate, di-calcium phosphate, and zinc phosphate. Significantly highest K-solubilization was observed with S. maltophila RCT31 followed by E. turicensis RCT5. However, the maximum zinc solubilization was reported with S. maltophila RCT31 followed by E. turicensis RCT5. The maximum ACC deaminase was quantified in the bacterium. Results revealed that the E. hormaechi RCT10 utilized seed leechates most effectively while root exudates were maximally utilized by S. maltophila RCT31. The pots experiment proves that S. maltophila RCT31 was the most effective bacterium and it was replication vis-à-vis field experiment. In particular, S. maltophila RCT31 holds strong potential to be possibly used as a bioformulation for the medicinal legume, as an economical and eco-friendly alternative to agrochemicals.