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20172
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Subject: Microbiology × End date: 2017 × Start date: 2017 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Impact assessment of nanozeolite and nanochitosan on plant-soil-microbe interaction using conventional and molecular methods
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2017-08) Khati, Priyanka; Sharma, Anita
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    ThesisItemOpen Access
    Characterization of phosphate solubilizing microorganisms from Garhwal Himalayan region and their field implications
    (G.B. Pant University of Agriculture and Technology, Pantnagar (Uttarakhand), 2017-01) Tomer, Supriya; Goel, Reeta
    Fourteen different soil samples (Mahabgarh, Kandakhal, Dugadda, Lansdowne, Amsour, Kotdwara, Dhanaulti, Surkhanda, Mussoorie, Chakrata, Satpuli, Shrinagar, Pauri and Chamba) from Garhwal region of Western Indian Himalayas were analyzed to explore the pqqD and pqqE gene abundance using qPCR. Results from pqqD and pqqE gene copy no. suggests that Kandakhal and Dhanaulti soils are most suitable for the isolation of phosphate solubilizing bacteria (PSB). Thirty three different rhizobacteria were isolated from these soils and out of them eight different bacteria were selected on the basis of solubilization index. Pseudomonas pelleroniana N-26, a standard PSB was procured from department culture collection. Furthermore, all these nine PSB were characterized for their phosphorous solubilizing efficacy by qualitative and quantitative estimation of phosphorous solubilization on Pikovskaya medium and NBRI-BPB liquid medium, respectively. Out of nine, three isolates named as Lysinibacillus macroides ST-30, Bacillus cereus ST-06 and Pseudomonas pelleroniana N-26 have exhibited better phosphorous solubilization efficiency. The subsequent effect of three selected isolates on plant growth promotion was unraveled by field trial experimentation on Cicer arietinum L. var. PG-186. Plant growth promotory activity of these strains were documented through increased plant growth in terms of shoot and root length, fresh and dry weight, nodule no., nodule fresh and dry weight (agronomical parameters), and chlorophyll content and nitrate reductase activity (biochemical parameters) of the plant leaves over control. The results of present study have shown that bacterial isolate ST-30 in combination with 20 Kg P2O5 ha-1 performed better in terms of agronomical parameters, biochemical parameters, P content of plant and soil, crop yield, harvest index and P economy over control treatment. DGGE analysis showed that all three PSB persisted till 75 days after sowing. Therefore, the above study demonstrated PSB, ST-30 in combination with 20 kg P2O5 ha-1 has the potential to substantially reduce or replace 50-100% phosphate fertilizers. PSB, ST-6 and N-26 have also shown potential to be used as bioinoculants for crop improvements.