Diversity and Symbiotic Effectiveness of Rhizobium Isolates Collected from Different Faba bean (Vicia faba) Growing Areas of North and South Gondar, Ethiopia

Fifty seven Rhizobium isolates were retrieved based on infection method from different faba bean growing areas of North and South Gondar, Ethiopia. In sand culture, only 35.5% of isolates showed nodulation. Analyses of variance indicated that inoculation of isolates improved tested traits significantly (p< 0.05) at all measured investigated parameters such as shoot length, shoot dry weight, and plant total nitrogen as 11, 28 and 31.3%, respectively, over nitrogen treated plants, 2, 10 and 29.4% respectively over standard Rhizobium and 55, 82.3 and 85.7% respectively over negative control treatments. Shoot dry weight was found to be strongly positively correlated with symbiotic effectiveness (r = 0.994, P <0.01). Based on symbiotic effectiveness, 80% of the tested isolates were found to be highly effective, 13% effective and only one isolate less effective. Therefore, there is a need for detail study of effective isolates tested under field conditions and molecular characterization for better classification.   Key words: Authentication, Legumes, Nitrogen fixation, Rhizobium, total nitrogen.