High diversity of chickpea Mesorhizobium species isolated in a Portuguese agricultural region

• DOI: 10.1016/j.femsec.2003.12.015
• Publication Date: 2004-02-17T10:08:37Z
• Authors: Marta Laranjo; Jorge Machado; J.Peter W. Young; Solange Oliveira
• Keywords: DNA, Bacterial; 0301 basic medicine; Portugal; Proteome; mesorhizobium; Molecular Sequence Data; Biodiversity; Sequence Analysis, DNA; 15. Life on land; DNA Fingerprinting; DNA, Ribosomal; Cicer; diversity; 03 medical and health sciences; Bacterial Proteins; RNA, Ribosomal, 16S; Cluster Analysis; Phylogeny; Alphaproteobacteria

Chickpea rhizobia isolated from Portuguese soils were assigned to the genus Mesorhizobium by 16S-rDNA sequencing. High species diversity was found within populations of an agricultural region in the south of Portugal. Besides the expected Mesorhizobium ciceri and M. mediterraneum, some isolates were close to M. loti or M. tianshanense and some formed a clade that may represent a new species. A new PCR-based approach, named direct amplified polymorphic DNA (DAPD) analysis, supported the 16S-based phylogeny. This suggests that this method could be used as a molecular tool to assess genetic relationships. Evaluation of genetic diversity by 16S-rDNA sequence, DAPD and protein profiles showed different levels of heterogeneity in natural populations.