Genotypic and phenotypic characterization of rhizobia that nodulate snap bean (Phaseolus vulgaris L.) in Egyptian soils

Elbanna, K. and Elbadry, M. and Gamal-Eldin, H. (2009) Genotypic and phenotypic characterization of rhizobia that nodulate snap bean (Phaseolus vulgaris L.) in Egyptian soils. Systematic and Applied Microbiology , 32 (7). pp. 522-530.

[img] PDF - Published Version
Restricted to ICRISAT researchers only


Snap bean fields in 12 of the 25 governorates of Egypt were surveyed to determine the distribution and taxonomy of snap bean-nodulating rhizobia. Nodulation rates in the field were very low, indicating that Egyptian soils do not have sufficient numbers of snap bean-compatible Rhizobium spp. A total of 87 rhizobial isolates were assayed on the most commonly grown cultivars in order to identify the most effective strains. The five most effective isolates (R11, R13, R28, R49 and R52) were fast-growing and utilized a wide range of carbon and nitrogen sources. A phylogenetic assignment of these strains by analysis of the 16S ribosomal RNA gene suggested that all fell within the Rhizobium etli-Rhizobium leguminosarum group. Strains R11, R49 and R52 all clustered with other identified R. etli strains, while strains R13 and R28 were more distinct. The distinctness of R13 and R28 was supported by physiological characteristics, such as their ability to utilize citrate, erythritol, dulcitol and lactate. Strains R13 and R28 also yielded the highest plant nitrogen content of all isolates. The highly effective strains isolated in this study, in particular strains R13 and R28, are promising candidates for improving crop yields. The data also suggested that these two strains represented a novel sub-group within the R. etli-R. leguminosarum group. As snap bean is a crop of great economic value to Egypt, the identification of highly effective rhizobial strains adapted to Egyptian soils, such as strains R13 and R28, is of great interest.

Item Type: Article
Additional Information: This investigation was supported in part by a grant from the MUCIA linkage project. The authors would like to thank Dr. Martin Krehenbrink (Oxford University, UK) for helpful discussions and suggestions.
Uncontrolled Keywords: Genotypic and phenotypic characterization, Rhizobium etli, Rhizobium leguminosarum, Egypt, Snap bean (Phaseolus vulgaris L.)
Author Affiliation: Department of Agricultural Microbiology, Faculty of Agriculture, Fayoum University, Egypt.
Subjects: Plant Production
Soil Science and Microbiology
Crop Improvement
Divisions: Common Bean
Depositing User: Mr Arbind Seth
Date Deposited: 12 Feb 2013 02:48
Last Modified: 12 Feb 2013 02:48
Official URL:

Actions (login required)

View Item View Item