henotypic and Symbiotic Effectiveness of Rhizobium Leguminosarum Bv. Viciae

Screening of symbiotically efficient rhizobial strains is the prerequisite in developing rhizobial inoculants forenhanced productivity of legumes. In this study, composite soil samples were collected from different lentilgrowing areas of Shewa in 2010. In 2011 and 2012, lentil nodulating rhizobial isolates were characterized formorphological, cultural and physiological properties under laboratory condition and evaluated for symbioticeffectiveness under greenhouse condition. In sand culture, the isolates showed significant differences for shootdry weight, nodule number, nodule dry weight, percentage of symbiotic effectiveness and percentage of totalnitrogen and were superior to the negative control. 5% of the isolates were highly effective and 59% wereeffective. The low effective and ineffective isolates accounted for 33% and 1%, respectively. The isolates showeddiversity in tolerance to salinity, different pH, temperature, antibiotics, heavy metals as well as utilization ofcarbon and nitrogen sources. Hence, the isolates are competitive enough to colonize the rhizosphere underdifferent edaphic and environmental conditions.