Priming effect of native rhizosphere bacteria on little millet (Panicum sumatrense)

Abstract

Summary The declining productivity of little millet (Panicum sumatrense) in a rural area in India necessitates finding a sustainable solution. A suitable composition of plant growth-promoting rhizobacteria (PGPR) in the rhizosphere of a crop is considered important for its optimum yield. Therefore, a study was undertaken to isolate and identify suitable bacteria and see their priming effect on the productivity of little millet. Rhizospheric soil samples were used to isolate bacteria on nitrogen-free Jensen's medium. Fast-growing rhizobacterial isolates FKK5 and DUM4, which exhibit significant selected plant growth-promoting activities, were selected. Little millet seeds were inoculated with selected PGPR and a non-native Azotobacter chroococcum before sowing. The inoculated plants were grown under semi-sterile poly-house conditions. Little millet inoculated with FKK5, DUM4, and A. chroococcum (5576) showed enhanced grain yield by 28.14%, 24.72%, and 20.43%, respectively, and enhanced total biomass yield by 23.08%, 21.87%, and 19.09%, respectively. The isolates were identified as Burkholderia sp. with 0.66% dissimilarity in 16S rDNA sequence with the most closely related species in the Genbank database. The native PGPR proved to be more effective compared to non-native PGPR as biofertilizers in restoring the productivity of the nutritionally important cereal.