Impact of Zinc Solubilizing Bacteria and Microbial Consortia on Growth and Yield of Rice (Oryza sativa L.)

Abstract

Rice (Oryza sativa L.) is a staple food for over half the world's population, particularly in Asia. This study explores the potential of Zn-solubilizing microbes to enhance micronutrient content in rice, aiming to address these deficiencies sustainably. Beneficial free-living soil bacteria, specifically plant growth-promoting rhizobacteria (PGPR), were investigated for their role in improving plant health and yield. Twenty-two bacterial isolates were screened for Zn solubilization, with Enterobacter hormaechei identified as the most promising. Field experiments with rice varieties PD 26 and NDR 359 involved treatmentssuch asT1 (Control), T2 (ZnSB1: Enterobacter hormaechei MT507226.1), T3 (Consortium1: Pantoearodasii MZ397586 + Seratiamarcesecens MW843567), and T4 (Consortium2: Enterobacter hormaechei MT507226.1 + Pantoearodasii MZ397586 + Seratiamarcesecens MW843567).  with individual and consortia of Zn-solubilizing bacteria. Significant improvements were shown in plant height, leaf area index (LAI), total chlorophyll, total dry matter (TDM), and grain yield. Results showed that Consortium1 (T3) significantly increased plant height by 7.94% for PD26 and 10.16% for NDR 359. Leaf Area Index (LAI) also improved notably under Consortium1, with increases of 15.56% for PD26 and 24.39% for NDR 359. Total chlorophyll content was highest under Consortium1 for PD26 (36.63% increase) and under Consortium2 for NDR 359 (31.41% increase). Total dry matter (TDM) showed substantial gains, especially in NDR 359 with Consortium2 treatment, achieving a 36.51% increase. Grain yield increased significantly across all treatments, with Consortium1 showing the highest yields: 12.26% for PD26 and 23.01% for NDR 359.Correlation analysis indicated strong positive relationships between plant height, TDM, and grain yield, underscoring the importance of these parameters in determining crop productivity. The findings suggest that microbial consortia, particularly Consortium1, can effectively replace traditional zinc fertilizers, enhancing sustainable agriculture by promoting plant growth and yield. These results are consistent with recent studies on the role of plant growth-promoting rhizobacteria (PGPR) in improving nutrient uptake and crop performance.