Isolation, Characterization and Identification of Rhizobia From Root Nodules of French Bean (Phaseolus vulgaris L.) Grown in Acid Soils
Abstract
Isolation, Characterization and Identification of Rhizobia From Root Nodules of French Bean (Phaseolus vulgaris L.) Grown in Acid Soils
Md. Abul Kashem1, Khadeza Yasmin1, Israt Jahan1, Md. Imran Khan1* and Saima Sadia Jui2
- Department of Soil Science, Sylhet Agricultural University, Sylhet-3100, Bangladesh
- Department of Plant Pathology and Seed Science, Sylhet Agricultural University, Sylhet-3100, Bangladesh
*Corresponding author: imrankhan.ag@student.sau.ac.bd
Abstract
A pot experiment was conducted and repeated for two years in the field of the Department of Soil Science, Sylhet Agricultural University. Six treatments, viz. T0 = Control (without Rhizobium inoculum) + Recommended Fertilizer (RF), T1 = R. inoculum 15 g/kg seed + RF, T2 = R. inoculum 30 g/kg seed + RF, T3 = R. inoculum 45 g/kg seed + RF, T4 = R. inoculum 60 /kg seed + RF and T5 = R. inoculum 75 g/kg seed + RF were used following CRD with four replications. Lime application was done @ 2 t/ha. The local variety of french bean was used. Data were collected on nodule formation at the flowering stage of french bean. In addition, plant height, leaves, biomass, pod number, length and weight, seed number and weight at harvest during second year. The results showed that nodules were found in all treatments except the control treatment in first year. The Rhizobium bacteria were isolated from effective nodules grown on YEMA medium, showed white translucent, irregular in shape, with smooth surface, mucous producing, circular, convex, raised elevations, glister and non-motile colonies. The strains were found to be fast-growing. The range of colony size was 2-3.5 mm. The identification of isolated pure cultures through colony morphology analysis and biochemical properties includes gram staining (negative), bromothymol blue test (acid producing) and mannitol salt agar (positive). The second-year experiment showed that the plant height (41.97 cm), leaves (32.25 plant-1), and biomass (60.44 plant-1) were the highest in T4 treatment. Additionally, the highest pods (60.44 plant-1), pods weight (28.54 g pod-1) and length (11.60 cm), seeds number (4.75 pod-1) and weight (8.02 g pod-1), effective nodules (109.25 plant-1) were observed in T4 treatment.
Keywords: French bean, Nodules, Rhizobium inoculum, and YEMA media.
