Rai, P. N.Bajeli, Jyoti2024-11-212024-11-212023-08-01Academic Researchhttps://krishikosh.egranth.ac.in/handle/1/5810216524Microbial inoculants or bioinoculants are promising candidate for sustainable management of cultivated ecosystems that improves crop growth and productivity by mobilizing soil nutrients and tolerance to abiotic stresses. The present experiment was conducted at G.B.P.U.A. & T. Pantnagar, during 2021-2023 to study the effects of bioinoculants and their consortia on growth, physiological and biochemical parameters in papaya var. Red Lady raised under well-watered and drought stress situations under modified growing conditions (glasshouse and naturally ventilated polyhouse conditions). The pot experiments were used for the study conducted in completely randomized design (CRD). Firstly, seeds were inoculated with one bacterial isolate (Pseudomonas pallaroniana strain DPB 16) and one fungal isolate (Fusarium pallidoroseum strain FP10) individually and in consortia with 1 ml/10 g and then two months old seedlings were treated with their individual and consortia at 20 ml/plant at the time of transplanting. The transplanted seedlings were then subjected to well - watered and drought stress conditions after four months of transplanting. The results depicted that the highest increase in shoot length, shoot diameter, root length, fresh and dry plant biomass, leaf area index (LAI) was found in the bioinoculant consortia treatment. The physiological and biochemical treatments viz., total chlorophyll content, total proline content, malondialdehyde content, hydrogen peroxide content, total phenol content and total flavonoid content was also found highest in the bioinoculant consortia treatment. The enzymatic activity such as Superoxide Dismutase (SOD), Catalase (CAT), Guaiacol Peroxidase (GPX), Ascorbate Peroxidase (APX), Glutathione Reductase (GR) and total protein content were found the highest in the microbial consortia both under well-watered and drought treatment. Moreover, the leaf nutrient content of nitrogen, phosphorus and potassium was also found the maximum under the consortia of the two strains used. The individual bioinoculant treatment was also found effective as compared to control in all the parameters. The colony forming unit (CFU) count of the soil around the rhizosphere of papaya plants was also higher in all the bioinoculant treatments as compared to control. Therefore, the study revealed that the microbial consortia was highly effective in promoting the growth and mitigating the drought stress in papaya var. Red Lady.EnglishThesis