Seed-coating fenugreek with Burkholderia rhizobacteria enhances yield in field trials and can combat Fusarium wilt

Two efficient bacterial strains (RHT8 and RHT12) were isolated from root nodules of fenugreek (Trigonella foenum-graecum L.) and identified as Burkholderia sp. on the basis of morphological, physiological, biochemical and molecular character. Both strains produced IAA, Siderophore, solubilized insoluble phosphate, but none of them showed volatile cyanogens production. The isolates exhibited chitinase, β-1,3-glucanase and ACC deaminase activity along with the growth inhibition of Fusarium oxysporum. It also caused degradation and digestion of cell wall components, resulting in hyphal perforation, loss of structural integrity of the mycelium, along with degradation of conidia. Both isolates Burkholderia sp. RHT8 and Burkholderia sp. RHT12 led to synergism and aggressive root coloniztion of the roots and enhanced growth. Bacterial consortia (RHT8 and RHT12) effectively resulted in increased grain yield by 40% of fenugreek as compared to control in field trial. Maximum vigour index, nodule number, root and shoot biomass were recorded with RHT8+RHT12 consortia in comparison to single inoculation as well as control. This study reveals the potential of Burkholderia sp. RHT8 and Burkholderia sp. RHT12 to be used as a bioinoculant for growth promotion of fenugreek along with the protection from Fusarium wilt.