Twenty-eight Rhizobium strains were isolated from the root nodules of faba bean (Vicia faba L.) collected from 11 governorates in Egypt. A majority of these strains (57%) were identified as Rhizobium leguminosarum bv. viciae (Rlv) based on analysis of a nodC gene fragment amplified using specific primers for these faba bean symbionts. The strains were characterized using a polyphasic approach, including nodulation pattern, tolerance to environmental stresses, and genetic diversity based on amplified ribosomal DNA-restriction analysis (ARDRA) of both 16S and 23S rDNA. Analysis of tolerance to environmental stresses revealed that some of these strains can survive in the presence of 1% NaCl and a majority of them survived well at 37 °C. ARDRA indicated that the strains could be divided into six 16S rDNA genotypes and five 23S rDNA genotypes. Sequence analysis of 16S rDNA indicated that 57% were Rlv, two strains were Rhizobium etli, one strain was taxonomically related to Rhizobium rubi, and a group of strains were most closely related to Sinorhizobium meliloti. Results of these studies indicate that genetically diverse rhizobial strains are capable of forming N2-fixing symbiotic associations with faba bean and PCR done using nodC primers allows for the rapid identification of V. faba symbionts.
Bibliographical noteFunding Information:
The authors wish to thank D. Werner and G. Moschetti for supplying reference strains, E. Hafez for funding the collection of soil samples, H. Abd-Elsalam for his effort to collect soil samples, and Oh Chang Jae for his help with software. This work was supported, in part, by the Korean Science and Engineering Foundation (KOSEF), through a post doctoral fellowship (to A. Shamseldin), and by a grant from Biogreen 21 (20050401034793) (to C.S. An).
- Egyptian soils
- Faba bean
- Genetic diversity
- Salinity and alkalinity of soils
- Sinorhizobium meliloti