DOI: 10.36347/sjavs.2021.v08i09.001

Pages: 82-86

Nitrogen (N) deficiency is one of the most common factors for reduction in yield of legume crops particularly in Ethiopia. The utilization of biological nitrogen fixation (BNF) by legume-Rhizobium symbiosis is most prominent symbiosis found in nature; so for increasing legume production and soil fertility we should use organic fertilizer such as bio fertilizer. The aim of this study was to isolate, identify and characterize the fababean nodulating Rhizobium isolates. Fababean (Vicia faba L.) rhizobia were isolated from nodules collected from four fababean growing area of Arsi zone of Ethiopia. A total of twenty rhizobia isolates were collected and characterized based upon their morphological and biochemical characteristics. Out of total, twelve isolates were selected as representative rhizobia samples. The result of this study showed that all isolates were fast-growing and failed to absorb Congo red. Cell size ranged from 2.1 to 5.2 mm. The smallest and largest colony diameter (2.1 and 5.2 mm) was recorded in isolates BKFB3 and MRFB10 respectively on YEMA medium. Isolates were capable of utilizing 50-100% of the tested carbohydrates. 75% of all isolates metabolized all the nitrogen sources and all isolates were utilized glutamine. All isolates were sensitive to neomycin and ampicillin at 20μg/ml concentration.