Genetic diversity and symbiotic efficiency of legume nodulating bacteria from different land use systems in Taita Taveta, Kenya



Título del documento: Genetic diversity and symbiotic efficiency of legume nodulating bacteria from different land use systems in Taita Taveta, Kenya
Revista: Tropical and subtropical agroecosystems
Base de datos: PERIÓDICA
Número de sistema: 000372749
ISSN: 1870-0462
Autors: 1
2
1
3
1
4
1
Institucions: 1Jomo Kenyatta University of Agriculture and Technology, Nairobi. Kenia
2University of Nairobi, Nairobi. Kenia
3United States International University, Nairobi. Kenia
4Kenya Forestry Research Institute, Nairobi. Kenia
Any:
Volum: 13
Número: 1
País: México
Idioma: Inglés
Tipo de documento: Artículo
Enfoque: Experimental, analítico
Resumen en inglés Populations of Legume Nodulating Bacteria (LNB) were assessed under glasshouse conditions from soils collected in Taita Taveta district, Kenya from various landuse systems. The populations were estimated by the most-probable-number (MPN) plant infection technique using Macroptilium atropurpureum (DC.) Urban (siratro) as the trap plant. The LNB populations varied from 1.1 x 10 to 6.1 x 106 cells g-1 of soil. There was apparent landuse effect on abundance of LNB with maize-bean cropping system and Shrubland giving high population estimates. Two thousand isolates of LNB were obtained from the nodules of siratro trap plant. These isolates were characterized on yeast extract mannitol mineral salts agar (YEMA) media containing bromothymol blue and two distinct rhizobia growth rate types were identified: fast growers (acid-producing) at 78.6% while slow growers (alkali-producing) comprised 21.4%. Symbiotic effectiveness of a selected number of the isolates ranged from 6.7% to 96.4% and no clear influence of landuse was observed. RFLP of amplified 16S rRNA genes of isolates with HaeIII and TaqI grouped the isolates into seven ribotypes and partial sequencing of 16S rRNA genes of isolates representative of the ribotypes further grouped the isolates into six genera namely; Sinorhizobium, Bradyrhizobium, Herbaspirillum, Agrobacterium, Rhizobium and Burkholderia. Landuse type was found to significantly influence the diversity of LNB (PO.05). The highest LNB richness of five genera was found in indigenous forest soils. While fallow/shrubland and maize based system had a total richness of four genera. Each of the remaining landuses had LNB total richness of two
Disciplines Agrociencias,
Biología
Paraules clau: Fitopatología,
Leguminosas,
Suelos,
Bacterias,
Uso del suelo,
Macroptilium atropurpureum,
Diversidad genética,
Nodulación,
Simbiosis,
Taita Taveta,
Kenia
Keyword: Agricultural sciences,
Biology,
Legumes,
Phytopathology,
Soils,
Bacteria,
Land use,
Macroptilium atropurpureum,
Genetic diversity,
Nodulation,
Symbiosis,
Taita Taveta,
Kenya
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