Mutch, L A and Young, J P W (2004) Diversity and specificity of Rhizobium leguminosarum biovar viciae on wild and cultivated legumes. Molecular Ecology. pp. 2435-2444. ISSN 0962-1083Full text available as:
The symbiotic partnerships between legumes and their root-nodule bacteria (rhizobia) vary widely in their degree of specificity, but the underlying reasons are not understood. To assess the potential for host-range evolution, we have investigated microheterogeneity among the shared symbionts of a group of related legume species. Host specificity and genetic diversity were characterized for a soil population of Rhizobium leguminosarum biovar viciae (Rlv) sampled using six wild Vicia and Lathyrus species and the crop plants pea (Pisum sativum) and broad bean (Vicia faba). Genetic variation among 625 isolates was assessed by restriction fragment length polymorphism (RFLP) of loci on the chromosome (ribosomal gene spacer) and symbiosis plasmid (nodD region). Broad bean strongly favoured a particular symbiotic genotype that formed a distinct phylogenetic subgroup of Rlv nodulation genotypes but was associated with a range of chromosomal backgrounds. Host range tests of 80 isolates demonstrated that only 34% of isolates were able to nodulate V. faba. By contrast, 89% were able to nodulate all the local wild hosts tested, so high genetic diversity of the rhizobial population cannot be ascribed directly to the diversity of host species at the site. Overall the picture is of a population of symbionts that is diversified by plasmid transfer and shared fairly indiscriminately by local wild legume hosts. The crop species are less promiscuous in their interaction with symbionts than the wild legumes.
|Copyright, Publisher and Additional Information:||© 2004 Blackwell Science Ltd. This is an electronic version of an article published in Molecular Ecology: complete citation information for the final version of the paper, as published in the print edition of Molecular Ecology, is available on the Blackwell Synergy online delivery service, accessible via the journal's website at http://www.blackwellpublishing.com/journal.asp?ref=0962-1083 or www.blackwell-synergy.com|
|Keywords:||domestication, host range, legumes, nodD, Rhizobium leguminosarum bv. viciae, symbiosis, FRAGMENT-LENGTH-POLYMORPHISM, PISUM-SATIVUM-L, BV-VICIAE, POPULATION-GENETICS, ENZYME POLYMORPHISM, SYMBIOTIC RHIZOBIUM, STRAIN SPECIFICITY, FIELD POPULATIONS, NODULATION FACTOR, AFGHANISTAN PEAS|
|Academic Units:||The University of York > Biology (York)|
|Depositing User:||Peter Young|
|Date Deposited:||22 Apr 2005|
|Last Modified:||17 Oct 2013 14:25|