DEVELOPMENT AND EVALUATION OF PROMISING BACTERIAL CONSORTIA FOR IMPROVING GROWTH AND YIELD OF RICE
| dc.contributor.advisor | Latha, P. C. | |
| dc.contributor.author | Srija, A. | |
| dc.date.accessioned | 2024-05-06T11:49:33Z | |
| dc.date.available | 2024-05-06T11:49:33Z | |
| dc.date.issued | 2023-02-09 | |
| dc.description.abstract | Rice (Oryza sativa) is the most important cereal crop in the world, feeding more than 50% of the world's population. To meet the world's demand for rice, it is imperative to find environmentally sound ways that supplement the need for fertilizers. The use of microbial inoculants is a desirable option since they can complement the fertilizer use. Microbial formulations developed using two or more beneficial plant growth promoting rhizobacteria, colonize the rhizosphere, plant roots and aids in plant development. Therefore, inoculating the plants with microbial consortia produces positive results because microbial consortia can generally accomplish tasks by mutual synergism thus performing better than individual strains. The present study “Development and evaluation of promising bacterial consortia for improving growth and yield of rice” was carried out to identify a potential consortia for rice. A total of 32 (IIRRSS22-1 to 27, P1, R1, M1, O1 and P2) bacteria isolated from the rhizosphere of rice were screened and scored for plant growth-promoting traits (phosphate, potassium, zinc solubilization, siderophore production, indole acetic acid production and HCN production) under in vitro conditions. Three potential (P1, IIRRSS22-1 and IIRRSS22-6) isolates having highest score with regard to plant growth promoting traits were selected and the bacterial performance was evaluated further by conducting germination test. All the isolates were then screened for abiotic stress tolerance such as salinity, temperature and drought tolerance. Scores were assigned to the isolates based on their ability to grow at different NaCl concentrations, temperature of 45℃ and water potential of -0.73MPa and three isolates (IIRRSS22-3, R1 and IIRRSS22-7) with highest score for abiotic stress tolerance traits were selected for in vitro germination studies. Agrichemical compatibility of bacterial isolates with fertilizers (Urea, Single super phosphate and Muriate of potash), insecticides (Cartap, Ferterra, Thiamethaxom), herbicides (Pretilachlor, Bispyribac sodium) and fungicides (Carbendazim, Mancozeb) used for rice cultivation was assessed by disc diffusion method. Based on the tolerance xv exhibited by the bacterial isolates, IIRRSS22-5, IIRRSS22-2 and IIRRSS22-4 with the highest tolerance score were selected for further experimentation. Nine isolates, 3 from each category (plant growth promoting traits, abiotic stress tolerance and compatibility with agrichemicals) were grouped into consortia (Consortium-1, 2 and 3) containing 3 bacterial isolates in each. These bacterial combinations were evaluated for compatibility among each other by cross streak method. All the isolates were compatible with each other and these consortia combinations and individual bacteria were evaluated for germination under in vitro conditions with Telangana sona (RNR-15048) as test variety. Consortium-1 exhibited highest germination percentage, seedling length, vigour index I and II when compared with control, individual inoculations and other consortia (C-2 and C-3). Based on the in vitro germination assay, consortium-1 was selected for further evaluation under pot culture conditions with different treatments tested at 100% RDF except the control treatment. The pot culture experiments were taken up during rabi 2021- 22, the plant morphological traits and yield traits of rice were recorded. The root length, shoot length, leaf area and plant biomass at active tillering and at the harvest stage were found to be highest with treatment T14 (100% RDF + Bacterial consortia (Seed treatment + Seedling root dip). The yield parameters of rice such as tiller number, panicle length, filled grains per panicle, test weight and grain yield as affected by different treatments were found to be highest in treatment T14 (100% RDF + Bacterial consortia (Seed treatment + Seedling root dip). The soil available nutrients and the nutrient uptake by the plants were also highest in the treatment T14 (100% RDF + Bacterial consortia (Seed treatment + Seedling root dip). The molecular characterization of bacterial partners in C-1 by 16S rRNA gene sequencing revealed that the bacterial isolates were Pseudomonas stutzeri (P1), Stenotrophomonas sp. (IIRRSS22-3), Achromobacter sp (IIRRSS22-5). The isolates in consortium-2 and 3 were identified as Achromobacter insuavis (IIRRSS22-6), Rhizobium sp, (IIRRSS22-1), Stenotrophomonas maltophilia (IIRRSS22-2), Ochrobacter anthropi (IIRRSS22-4). Achromobacter xylosoxidans IIRRSS22-7. Based on the results obtained, the present study showed that the consortia (C-1) which consisted of rhizobacterial isolates (Pseudomonas stutzeri, Stenotrophomonas sp, Achromobacter sp) with multiple plant beneficial traits along with tolerance to eco physiological stresses has enhanced rice plant growth and yield parameters under pot culture conditions. This study also suggests that the use of plant-beneficial bacteria as a consortium results in better plant performance rather than as a single strain. | |
| dc.identifier.uri | https://krishikosh.egranth.ac.in/handle/1/5810208710 | |
| dc.language.iso | English | |
| dc.pages | 152 | |
| dc.publisher | PROFFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY | |
| dc.relation.ispartofseries | D10984 | |
| dc.sub | Agricultural Microbiology | |
| dc.theme | M. Sc. | |
| dc.these.type | M.Sc | |
| dc.title | DEVELOPMENT AND EVALUATION OF PROMISING BACTERIAL CONSORTIA FOR IMPROVING GROWTH AND YIELD OF RICE | |
| dc.type | Thesis |