Effects of Plant Growth–Promoting Rhizobacteria on Seed Germination and Early Growth Performance of FKR62N Rice (Oryza sativa L.) Variety in Burkina Faso

Abstract

Rice productivity is often hampared by low soil fertility and and excessive dependence on chemical fertilizers. This study evaluated the effects of plant growth–promoting rhizobacteria (PGPR) on rice germination, vegetative growth, and biomass production. Rice seeds were inoculated with bacterial isolates (VDK5AN, VDK12AE, M14AN, TI13AN, and M16AN) belonging to the genera Bacillus, Lysinibacillus, and Terrilactibacillus. Germination parameters, including germinated seed number, seedling height, and radicle length, were assessed, followed by a pot experiment to evaluate plant growth and yield under bacterial and NPK + urea fertilization. Uninoculated seeds and plants were used as controls. Bacterial treatments significantly influenced seed germination and early seedling development (p < 0.001), with all isolates outperforming the control. Isolates M14AN, TI13AN, and VDK5AN showed the strongest and earliest stimulatory effects. Seedling height and radicle length increased progressively and were significantly enhanced by bacterial inoculation, particularly from 7 days after inoculation onward (p < 0.001). Plant height, tiller number, and biomass accumulation were also significantly affected by treatments and growth stage (p < 0.001). Inoculated plants, especially those treated with VDK5AN, VDK12AE, TI13AN, and M16AN, exhibited superior vegetative growth compared with the control and, in several cases, the NPK treatment. Aerial and root biomass were markedly increased by bacterial inoculation (p < 0.0001), with isolates M14AN and VDK5AN producing the highest yields. Overall, these results demonstrate the potential of the tested PGPR isolates to enhance rice growth and biomass production, highlighting their promise as sustainable biofertilizers. Further studies are needed to elucidate their mechanisms of action and to validate their effectiveness under field conditions.