2017, VOLUME 4 ISSUE 1Pages: 183-191
Isolation and characterization of nitrogen fixing bacteria that nodulate alien invasive plant species Prosopis juliflora (Swart) DC. in Marigat, Kenya
John O. Otieno*, David W. Odee, Stephen F. Omondi, Charles Oduor and Oliver Kiplagat
*Kenya Forestry Research Institute, P.O. Box 20412-00200, Nairobi, Kenya
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A total of 150 bacterial strains were isolated from the root nodules of Prosopis juliflora growing in soils collected from Marigat area of Kenya. Soil samples from representative colonized zones of Tortilis, Grass and Prosopis were used in trapping the microsymbionts. A physiological plate screening allowed the selection of 60 strains which were characterized based on morphological, cultural and biochemical characteristics. Tolerance to salinity, acid and alkaline pH and resistance to antibiotics were studied as phenotypic markers. Morphological characteristics allowed the description of a wide physiological diversity among tested isolates. Establishing mutualistic interactions in novel environments is important for the successful establishment of some non-native plant species. The associations may have negative impact on the interaction networks of the native species whereby non-native species becoming dominant. Our study suggests that P. juliflora may have led to the diversity of N-fixing microsymbionts observed in the study area. The study provides basis for further research on the phylogeny of rhozobial strains nodulating P. juliflora, as well as their use as inoculants to improve growth and nitrogen fixation in arid lands of Kenya. The data obtained in this study can be used for strain improvement and cross-inoculation experiments with different species when searching for well adapted and compatible partners.