Mekasha Tsegaye, Fassil Assefa, Jemaneh Zeleke
Department of Biology, College of Natural and Computational Sciences, Wolaita Sodo University, Ethiopia
Department Microbial, Cellular and Molecular Biology, College of Life Science, Addis Ababa University, Ethiopia
Institute of Molecular Genetics and Genetic Engineering (IMGGE), University of Belgrade, Serbia
Key words: Fenugreek, Rhizobium isolates, Nodulation, East Shewa, North Shewa.
Fenugreek (Trigonella foenum-graecum L.), a crop with a long history in Ethiopian agriculture, is known to form a symbiosis with nitrogen-fixing bacteria (Rhizobia). In the current study, Rhizobium bacteria nodulating fenugreek in the East and North Shewa of Ethiopia, where the plant is commonly grown, were collected and characterized. All isolated strains were fast growing on Yeast Extract Mannitol Agar (YEMA) plates. After 3 days of incubation at 30°C, the rounded colonies had mucous transparent to creamy appearance. Most isolates were able to produce acid after 72 h of incubation and only three isolates slightly absorbed Congo red. Heterotrophic competence among isolates was also observed from their utilization capabilities of various carbon and nitrogen sources. Interestingly, the isolates showed strong tolerance to different eco-physiological parameters (pH, temperature, salt concentration, and intrinsic antibiotic resistance). Plants inoculated with different isolates showed differences with respect to nodule number and dry weight and shoot dry weight. Two isolates (AAUFR-26 and AAUFR-30) from North Shewa, representing 12.5% of the isolates, were highly effective (> 80%) in forming symbiosis with fenugreek whereas, 67% were found to be effective (50-80%). More shoot dry weight were observed for whichisolates from North Shewa were inoculated, indicating that some soil-related factors such as pH might have affected the symbiotic effectiveness. Overall, the present study provides a baseline data for further investigations on nitrogen fixation capability of fenugreek associated Rhizobial strains so that efficient isolates,may be used as biofertilizers in areas where indigenous Rhizobium failed to nodulate fenugreek.
Get the original articles in Source: Volume 7, Number 1, July 2015 – IJAAR
Published By: International Network for Natural Sciences