Relationships between rhizobial diversity and host legume nodulation and nitrogen fixation in tropical ecosystems

A. Bala, K.E. Giller

Research output: Contribution to journalArticleAcademicpeer-review

11 Citations (Scopus)

Abstract

With recent advances in rhizobial phylogeny, questions are being asked as to how an ecological framework can be developed so that rhizobial classification and diversity could have greater practical applications in enhancing agricultural productivity in tropical ecosystems. Using the results of studies on tropical rhizobia which nodulate agroforestry tree legumes, three ecological aspects of rhizobial biodiversity were used to illustrate how its potential can be exploited. The results showed that legumes nodulate with diverse rhizobial types, thus contributing to the success of legumes in colonising a wide range of environments. There was an apparent shift in the relative dominance of rhizobia populations by different rhizobial types as soil pH changed. The Rhizobium tropici-type rhizobia were predominant under acidic conditions, Mesorhizobium spp. at intermediate pH and Sinorhizobium spp. under alkaline conditions. The R. tropici-type rhizobia were the most effective symbiotic group on all the host legumes. However, strains of Sinorhizobium spp. were as effective as the R. tropici types in N2-fixation on Gliricidia sepium, Calliandra calothyrsus and Leucaena leucocephala; while Mesorhizobium strains were equally as effective as the R. tropici types on Sesbania sesban. Classification of rhizobia based on phenotypic properties showed a broad correlation with groupings based on 16S rRNA sequence analysis, although a few variant strains nested with the dominant groups in most of the clusters. Some of the phenotypic characters that differentiated different rhizobial groups are highlighted and a case is made for the need to standardise this method
Original languageEnglish
Pages (from-to)319-330
JournalNutrient Cycling in Agroecosystems
Volume76
Issue number2-3
DOIs
Publication statusPublished - 2006

Fingerprint

Rhizobium tropici
nodulation
nitrogen fixation
rhizobacterium
Rhizobium
legumes
ecosystems
Sinorhizobium
Mesorhizobium
Calliandra calothyrsus
Sesbania sesban
taxonomy
Gliricidia sepium
Leucaena leucocephala
sesbania
agroforestry
dominance (genetics)
soil pH
sequence analysis
fixation

Keywords

  • genetic diversity
  • symbiotic specificity
  • vigna-unguiculata
  • zimbabwean soils
  • kenyan soils
  • populations
  • bradyrhizobium
  • competition
  • nodules
  • beans

Cite this

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title = "Relationships between rhizobial diversity and host legume nodulation and nitrogen fixation in tropical ecosystems",
abstract = "With recent advances in rhizobial phylogeny, questions are being asked as to how an ecological framework can be developed so that rhizobial classification and diversity could have greater practical applications in enhancing agricultural productivity in tropical ecosystems. Using the results of studies on tropical rhizobia which nodulate agroforestry tree legumes, three ecological aspects of rhizobial biodiversity were used to illustrate how its potential can be exploited. The results showed that legumes nodulate with diverse rhizobial types, thus contributing to the success of legumes in colonising a wide range of environments. There was an apparent shift in the relative dominance of rhizobia populations by different rhizobial types as soil pH changed. The Rhizobium tropici-type rhizobia were predominant under acidic conditions, Mesorhizobium spp. at intermediate pH and Sinorhizobium spp. under alkaline conditions. The R. tropici-type rhizobia were the most effective symbiotic group on all the host legumes. However, strains of Sinorhizobium spp. were as effective as the R. tropici types in N2-fixation on Gliricidia sepium, Calliandra calothyrsus and Leucaena leucocephala; while Mesorhizobium strains were equally as effective as the R. tropici types on Sesbania sesban. Classification of rhizobia based on phenotypic properties showed a broad correlation with groupings based on 16S rRNA sequence analysis, although a few variant strains nested with the dominant groups in most of the clusters. Some of the phenotypic characters that differentiated different rhizobial groups are highlighted and a case is made for the need to standardise this method",
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language = "English",
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journal = "Nutrient Cycling in Agroecosystems",
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Relationships between rhizobial diversity and host legume nodulation and nitrogen fixation in tropical ecosystems. / Bala, A.; Giller, K.E.

In: Nutrient Cycling in Agroecosystems, Vol. 76, No. 2-3, 2006, p. 319-330.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Relationships between rhizobial diversity and host legume nodulation and nitrogen fixation in tropical ecosystems

AU - Bala, A.

AU - Giller, K.E.

PY - 2006

Y1 - 2006

N2 - With recent advances in rhizobial phylogeny, questions are being asked as to how an ecological framework can be developed so that rhizobial classification and diversity could have greater practical applications in enhancing agricultural productivity in tropical ecosystems. Using the results of studies on tropical rhizobia which nodulate agroforestry tree legumes, three ecological aspects of rhizobial biodiversity were used to illustrate how its potential can be exploited. The results showed that legumes nodulate with diverse rhizobial types, thus contributing to the success of legumes in colonising a wide range of environments. There was an apparent shift in the relative dominance of rhizobia populations by different rhizobial types as soil pH changed. The Rhizobium tropici-type rhizobia were predominant under acidic conditions, Mesorhizobium spp. at intermediate pH and Sinorhizobium spp. under alkaline conditions. The R. tropici-type rhizobia were the most effective symbiotic group on all the host legumes. However, strains of Sinorhizobium spp. were as effective as the R. tropici types in N2-fixation on Gliricidia sepium, Calliandra calothyrsus and Leucaena leucocephala; while Mesorhizobium strains were equally as effective as the R. tropici types on Sesbania sesban. Classification of rhizobia based on phenotypic properties showed a broad correlation with groupings based on 16S rRNA sequence analysis, although a few variant strains nested with the dominant groups in most of the clusters. Some of the phenotypic characters that differentiated different rhizobial groups are highlighted and a case is made for the need to standardise this method

AB - With recent advances in rhizobial phylogeny, questions are being asked as to how an ecological framework can be developed so that rhizobial classification and diversity could have greater practical applications in enhancing agricultural productivity in tropical ecosystems. Using the results of studies on tropical rhizobia which nodulate agroforestry tree legumes, three ecological aspects of rhizobial biodiversity were used to illustrate how its potential can be exploited. The results showed that legumes nodulate with diverse rhizobial types, thus contributing to the success of legumes in colonising a wide range of environments. There was an apparent shift in the relative dominance of rhizobia populations by different rhizobial types as soil pH changed. The Rhizobium tropici-type rhizobia were predominant under acidic conditions, Mesorhizobium spp. at intermediate pH and Sinorhizobium spp. under alkaline conditions. The R. tropici-type rhizobia were the most effective symbiotic group on all the host legumes. However, strains of Sinorhizobium spp. were as effective as the R. tropici types in N2-fixation on Gliricidia sepium, Calliandra calothyrsus and Leucaena leucocephala; while Mesorhizobium strains were equally as effective as the R. tropici types on Sesbania sesban. Classification of rhizobia based on phenotypic properties showed a broad correlation with groupings based on 16S rRNA sequence analysis, although a few variant strains nested with the dominant groups in most of the clusters. Some of the phenotypic characters that differentiated different rhizobial groups are highlighted and a case is made for the need to standardise this method

KW - genetic diversity

KW - symbiotic specificity

KW - vigna-unguiculata

KW - zimbabwean soils

KW - kenyan soils

KW - populations

KW - bradyrhizobium

KW - competition

KW - nodules

KW - beans

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DO - 10.1007/s10705-005-2003-y

M3 - Article

VL - 76

SP - 319

EP - 330

JO - Nutrient Cycling in Agroecosystems

JF - Nutrient Cycling in Agroecosystems

SN - 1385-1314

IS - 2-3

ER -