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| Title: | Pattern of Nodulation and Nitrogen Fixing Performance of Introduced Forage Legumes in Some Parts of North Gondar, Ethiopia |
| Authors: | Fekadu, Shimekite |
| Keywords: | Introduced forage legumes
Nitrogen fixation
Nodulation
Rhizobium leguminosarum var viceae
Sinorhizobium meliloti
Bradyrhizobium spp |
| Date Added: | 31-Aug-2007 |
| Abstract: | Six exotic herbaceous forage legumes namely, Desmodium uncinatum (desmodium), Lablab
purpureus (lablab), Medicago sativa (alfalfa), Trifolium repens (white clover), Vigna unguiculata
(cowpea) and Vicia dasycarpa (common vetch) were induced for nodulation on Dembia and
Wegera soils for which all except, desmodium and white clover legumes nodulated their host.
From the nodulated legumes, nineteen isolates were isolated and characterized based on their
morphological, cultural, and physiological properties. In the preliminary screening eleven isolates
of alfalfa, three isolates of vetch were assigned as fast growing Sinorhizobium meliloti and R.
leguminosarum var viceae respectively. The isolates of lablab (three) and cowpea (two) were
assigned as slow growing Bradyrhizobium species. The vetch isolates AUVR11, AUVR13 from
Wegera and AUVR14 (R. leguminosarum var viceae) from Dembia and alfalfa isolates AUMR3
and AUMR10 from Wegera; and AUMR9 from Dembia (S. meliloti) were found to renodulate
their respective hosts. The nodulating isolates were studied with respect to their relative
effectiveness in nitrogen fixation. Inoculation of vetch by R. leguminosarum var viceae showed
significant differences in percent effectiveness (30%-83%) on vetch, and (50-100%) on alfalfa.
AUVR13 (vetch) and AUMR9 (alfalfa) were found to be the most efficient strains with
percentage effectiveness of 83% and 100% respectively. Although the performance of the vetch
isolates on two different soils showed that there was no any inter strain difference on each soil,
Dembia soil responded better in SDW and TN than Holetta soil indicating that some soil-related
factors such as pH affect symbiotic effectiveness. Generally, the fact that the number of infective
and effective isolates of the introduced legumes in Dembia and Wegera weredas was very small
may necessitate more exhaustive screening in different regions and the need for inoculation with
effective exotic endosymbionts to fully realize the potential of Biological Nitrogen Fixation in
forage production in animal husbandry. |
| Description: | A Thesis Submitted to the School of Graduate Studies of Addis Ababa
University in Partial Fulfillment of the Requirements for the Degree of
Masters of Science in Applied Microbiology |
| URI: | http://hdl.handle.net/123456789/35 |
| Appears in: | Thesis - Biology
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