Summary
We examined the influence of a vesicular-arbuscular (VAM) fungus (Glomus pallidum Hall) on the competitive ability of introduced and native Bradyrhizobium strains to nodulate cowpeas [Vigna unguiculata (L) Walp]. Our experiments in non-sterilized soil revealed that in the presence of VAM fungus, introduced Bradyrhizobium spp. strains become more competitive than native rhizobia. For example, strain JRC29 occupied 59.2% of the total nodules when inoculated alone, but this figure increased to 71.2% when JRC29 was used in dual inoculations with VAM fungus. A similar pattern of enhanced competitiveness for nodule formation was observed with the two other strains in the presence of the VAM fungus. Our results suggest that the competitiveness of rhizobia can be enhanced by co-inoculating with a selected strain of a VAM fungus.
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Aarons S, Ahmad MH (1987) Growth and survival of cowpea rhizobia in bauxitic silt loam and sandy clay loam soils. FEMS Microbiol Ecol 45:77–83
Ahmad MH, McLaughlin W (1985) Ecology and genetics of tropical rhizobia species. Biotech Adv 3:155–170
Ahmad MH, Eaglesham ARJ, Hassouna S, Seaman B, Ayanaba A, Mulongoy K, Pulver E (1981 a) Examining the potential for inoculant use with cowpea in West African soils. Trop Agric (Trinidad) 58:325–335
Ahmad MH, Eaglesham ARJ, Hassouna S (1981 b) Examining serological diversity of cowpea rhizobia by the ELISA technique. Arch Microbiol 130:281–287
Alexander M (1984) Ecology of Rhizobium. In: Alexander M (ed) Biological nitrogen fixation and its ecological basis. Plenum Press, New York, pp 39–50
Ames RN, Bethlenfalvay GJ (1987) Localized increase in nodule activity but no competitive interaction of cowpea rhizobia due to pre-establishment of vesicular-arbuscular mycorrhiza. New Phytol 106:207–215
Ames RN, Reid CPP, Ingham ER (1984) Rhizosphere bacterial population responses to root colonization by a vesicular-arbuscular mycorrhizal fungus. New Physiol 96:555–563
Ames RN, Thiagarajan TR, Ahmad MH, McLaughlin W (1991) Co-selection of compatible rhizobia and VA mycorrhizal fungi for cowpea in sterilized and non-sterilized soil. Biol Fertil Soil 12:112–116
Dowling DN, Broughton WJ (1986) Competition for nodulation of legumes. Annu Rev Microbiol 40:131–157
Eaglesham ARJ, Ahmad MH, Hassouna S, Barbara J (1982) Cowpea rhizobia producing dark nodules: Use in competition studies. Appl Environ Microbiol 44:611–618
Habte M, Barrion M (1984) Interaction of Rhizobium sp. with toxin producing fungus in culture medium and in a tropical soil. Appl Environ Microbiol 47:1080–1083
Kosslak RM, Bohlool BB (1985) Influence of environmental factors on interstrain competition in Rhizobium japonicum. Appl Environ Microbiol 49:1128–1133
McLaughlin W, Ahmad MH (1984) Intrinsic antibiotic resistance and streptomycin uptake in cowpea rhizobia. FEMS Microbiol Lett 21:299–303
Meyer JR, Linderman RG (1986) Selective influence on populations of rhizosphere and rhizoplane bacteria and actinomycetes by mycorrhizas formed by Glomus fasciculatum. Soil Biol Biochem 18:191–196
Thiagarajan TR, Ames RN, Ahmad MH (1992) Response of cowpea (Vigna unguiculata (L) Walp) to inoculation with co-selected VAM fungi and Rhizobium strains in field trials. Can J Microbiol 38: 573–576
Uddin RM, McLaughlin W, Ahmad MH (1984) Competition between inoculum and native rhizobia for nodulation of cowpea (Vigna unguiculata (L) Walp): Use of a dark-nodule strain. Plant and Soil 81:305–307
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Thiagarajan, T.R., Ahmad, M.H. Influence of a vesicular-arbuscular mycorrhizal fungus on the competitive ability of Bradyrhizobium spp. for nodulation of cowpea Vigna unguiculata (L.) Walp in non-sterilized soil. Biol Fertil Soils 15, 294–296 (1993). https://doi.org/10.1007/BF00337215
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DOI: https://doi.org/10.1007/BF00337215