Isolation and Screening of Rhizosphere Bacteria from Grasses in East Kavango Region of Namibia for Plant Growth Promoting Characteristics
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A diverse group of soil bacteria known as plant growth promoting rhizobacteria (PGPR) is able to inhabit the area close to plant roots and exert beneficial effects on plant growth. Beneficial interactions between rhizospheric bacteria and plants provide prospects for isolating culturable PGPR that can be used as bio-fertilizers for sustainable crop production in communities that cannot easily afford chemical fertilizers. This study was conducted with the aim of isolating rhizospheric bacteria from grasses along the Kavango River and screening the bacterial isolates for plant growth promoting characteristics. The bacteria were isolated from rhizospheres of Phragmites australis, Sporobolus sp., Vetiveria nigritana, Pennisetum glaucum and Sorghum bicolor. The isolates were screened for inorganic phosphate solubilization, siderophore production and indole-3-acetic acid (IAA) production. The nitrogen-fixing capability of the bacteria was determined by screening for the presence of the nifH gene. Up to 21 isolates were obtained from P. australis, Sporobolus sp., S. bicolor, P. glaucum and V. nigritana. The genera Bacillus, Enterobacter, Kocuria, Pseudomonas and Stenotrophomonas, identified via 16S rDNA were represented in the 13 PGPR strains isolated. The isolates exhibited more than one plant growth promoting trait and they were profiled as follows: three phosphate solubilizers, four siderophore producers, eight IAA producing isolates and five nitrogen-fixers. These bacteria can be used to develop bio-fertilizer inoculants for improved soil fertility management and sustainable production of local cereals.
KeywordsPlant Growth Promote Rhizobacteria Stenotrophomonas nifH Gene Pennisetum Glaucum Kocuria
This study was funded by The Future Okavango (TFO) Project through the BMBF (Federal Ministry of Education and Research, Germany) Research Framework Programme, Research for Sustainable Development (FONA).
Compliance with Ethical Standard
Conflict of interest
The authors declare that they have no conflict of interest.
- 2.Barraquio WL, Segubre EM, Gonzalez MAS, Verma SC, James EK, Ladha JK, Tripathi AK (2000) Diazotrophic enterobacteria: what is their role in the rhizosphere of rice. In: Ladha JK, Reddy PM (eds) The quest for nitrogen fixation in rice. Kluwer Academic Publishers, Philippines, pp 93–118Google Scholar
- 3.Bashan Y, Holguin G, Lifshitz R (1993) Isolation and characterization of plant growth-promoting rhizobacteria. In: Glick BR, Thompson JE (eds) Methods in plant molecular biology and biotechnology. CRC Press, Florida, pp 331–345Google Scholar
- 4.Burbano Roa CS (2011) Molecular analysis of root-associated diazotrophs in important plants from Southern Africa and South America. Dissertation, University of BremenGoogle Scholar
- 6.Chaiharn M, Chunhaleuchanon S, Kozo A, Lumyong S (2008) Screening of rhizobacteria for their plant growth promoting activities. KMITL Sci Technol J 8(1):18–23Google Scholar
- 7.Edi-Premono M, Moawad MA, Vleck PLG (1996) Effect of phosphate solubilizing Pseudmonas putida on the growth of maize and its survival in the rhizosphere. Indones. J Crop Sci 11:13–23Google Scholar
- 10.Glick BR (2012) Plant growth-promoting bacteria: mechanisms and applications. Scientifica 2012Google Scholar
- 12.Govindasamy V, Senthilkumar M, Magheshwaran V, Kumar U, Bose P, Sharma V, Annapurna K (2011) Bacillus and Paenibacillus spp.: potential PGPR for sustainable agriculture. In: Maheshwari DK (ed) Plant growth and health promoting bacteria. Springer, Germany, pp 333–364Google Scholar
- 16.Kloepper JW, Schroth MN (1978) Plant growth-promoting rhizobacteria on radishes. In: Station de pathologie vegetale et phyto-bacteriologie (Ed.), Proceedings of the 4th International Conference on Plant Pathogenic Bacteria 2: 879–882Google Scholar
- 23.Piggot PJ (2009) Bacillus Subtilis. In: Schaechter M (ed) Desk encyclopedia of microbiology, 2nd edn. Academic Press, California, pp 154–165Google Scholar
- 25.Reinhold B, HurekT Niemann EG, Fendrik I (1986) Close association of Azospirillum and diazotrophic rods with different root zones of Kallar grass. App Environ Microb 52(Suppl 3):520Google Scholar
- 26.Reinhold-Hurek B, Hurek T (2000) Reassessment of the taxonomic structure of the diazotrophic genus Azoarcus sensu lato and description of three new genera and new species, Azovibrio restrictus gen. nov., sp. nov., Azospira oryzae gen. nov., sp. nov. and Azonexus fungiphilus gen. nov., sp. nov. Int J Syst Evol Microbiol 50(2):649–659CrossRefPubMedGoogle Scholar
- 30.Saharan BS, Nehra V (2011) Plant growth promoting rhizobacteria: a critical review. Life Sci Med Res 21:1–30Google Scholar
- 36.United Nations Development Programme (UNDP) (2010) Country pilot partnership: adapting to climate change through the improvement of traditional crops and livestock farming in Namibia. www.thegef.org/gef/sites/thegef.org/files/gef_prj_docs/GEFProjectDocuments/M&E/TE/FY2012/UNDP/G002915/2915_3598_Namibia_CCA_TE.pdf
- 38.World Bank (2009) Namibia: country brief. Open knowledge repository. https://openknowledge.worldbank.org/handle/10986/2630
- 39.Yasmin F, Othman R, Sijam K, Saad MS (2010) Characterization of beneficial properties of plant growth-promoting rhizobacteria isolated from sweet potato rhizosphere. Afr J Microbiol Res 3(11):815–821Google Scholar