Enhancing rice productivity, grain quality and soil fertility through Pseudomonas mosselii biopriming

Achieving higher rice productivity without compromising grain or soil quality remains a key challenge in sustainable agriculture. Although the endophytic bacterial strain Pseudomonas mosselii has shown potential in enhancing rice growth, its role in improving grain nutritional quality and soil health remains underexplored. This study evaluated the role of P. mosselii PR5 in promoting rice growth, yield, grain quality, and soil health through various application methods: seed priming (SP), seedling priming (SeP), bacterial culture filtrate (BCF) foliar application, SP combined with BCF (SP + BCF), and SeP combined with BCF (SeP + BCF). All treatments significantly improved rice growth and yield traits. Bacterial applications increased the plant height (4.1-9.4%), shoot biomass (30.5-64.3%), root biomass (31.8-64.5%), photosynthetic pigments (8.2-36.4%), filled grain per pot (4.2-11.8%), compared to the control. Notably, SP + BCF and SeP + BCF treatments increased rice yield by 55.2% and 48% respectively, over the control. PR5 application significantly increased the nutrient contents in rice, enhancing protein and fat while reducing carbohydrate content in grain. The SP + BCF treatment enhanced the availability of sulfur (S), magnesium (Mg), iron (Fe), and organic matter in the rhizospheric soil, whereas SeP + BCF treatment improved nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and zinc (Zn) availability, contributing to soil fertility restoration. Multivariate analysis also confirmed a positive association of growth and yield parameters and most of the nutrients with these two treatments. These findings suggest that P. mosselii PR5, applied via seed or seedling priming in combination with BCF foliar treatment, offers a promising strategy for sustainable rice cultivation and soil health management.