Beneficial Tripartite Association of Pseudomonas Protegens, AM Fungi and Rice Promotes Growth Under Aerobic Conditions

The positive impact of microbial inoculants on plants is well documented. In this study, we examined two rice varieties - PB 1509 (lowland) and Satyabhama (upland) - to investigate the effects of co-inoculating AMF and Pseudomonas protegens strain Ekn 03, under aerobic conditions. Co-inoculation with Pseudomonas protegens Ekn 03 significantly enhanced root mycorrhizal colonization in both varieties, while also increasing root surface area. In dually inoculated plants, shoot fresh weight, shoot dry weight, and root dry weight were 28.5%, 87.5%, and 22.2% higher, respectively, compared to non-inoculated control plants. Dually inoculated plants showed a 31.6% increase in chlorophyll content compared to control plants. Nitrate reductase (NR) activity was 28% higher in dually inoculated plants, comparable to those treated with RDF. Additionally, a significant correlation was observed between plant biomass, NR, and glutamine synthetase (GS) activity. This tripartite association improves phosphorus and nitrogen acquisition, indicating the potential for reduced chemical input use, with P. protegens Ekn 03 identified as an effective PGPR.