Diversity patterns of Rhizobiaceae communities inhabiting soils, root surfaces and nodules reveal a strong selection of rhizobial partners by legumes.
Environ Microbiol
; 18(8): 2375-91, 2016 09.
Article
in En
| MEDLINE
| ID: mdl-26395550
ABSTRACT
Current knowledge about rhizobial diversity patterns in non-nodule habitats is scarce, limiting our understanding of basic aspects of rhizobial ecology like competitiveness for nodule occupancy and host effects on community structure. We used a combination of cultivation-dependent and independent approaches to analyse alpha and beta diversity patterns of Rhizobiaceae communities from a conserved seasonally dry tropical forest site in central Mexico and two nearby agricultural fields. Lineage-specific recA amplicon libraries were generated from soil DNA and their sequences compared with those from root surface and nodule isolates recovered in trapping experiments from two native Acacia species and two Phaseolus vulgaris cultivars. Rarefaction analyses revealed that Rhizobiaceae diversity in soils is larger than on root surfaces, and smallest in nodules. A 'rare biosphere'-like distribution of species was found in the three habitats. Multivariate statistical analyses demonstrated that the plant genus exerted a stronger influence than the land-usage regime on the diversity of rhizobia associated with hosts. Rhizobium etli was the dominant Rhizobiaceae found in the soil libraries. It dominated nodulation of Acacia spp. and predominately harboured symbiovar mimosae-like nodC genes. A novel Rhizobium lineage (Rsp1) dominated bean nodulation. Specialist and generalist genotypes for host nodulation were detected in both species.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Rhizobiaceae
/
Soil Microbiology
/
Phaseolus
/
Biodiversity
/
Root Nodules, Plant
Country/Region as subject:
Mexico
Language:
En
Journal:
Environ Microbiol
Journal subject:
MICROBIOLOGIA
/
SAUDE AMBIENTAL
Year:
2016
Document type:
Article
Affiliation country: