Biology and Fertility of Soils

, Volume 27, Issue 4, pp 335–341

Identification and characterization of salt- and thermo-tolerant Leucaena-nodulating Rhizobium strains

Authors

  • F. M. Hashem
    • Plant Sciences Institute, Beltsville Agricultural Research Center, USDA, ARS, 10300 Baltimore Ave., Beltsville, MD 20705, USA e-mail: fhashem@asrr.arsusda.gov, Tel.: +001-301-5045736, Fax: +001-301-5045728
  • D. M. Swelim
    • Soil, Water and Environment Research Institute, Agricultural Research Center, Giza 12619, Egypt
  • L. D. Kuykendall
    • Plant Sciences Institute, Beltsville Agricultural Research Center, USDA, ARS, 10300 Baltimore Ave., Beltsville, MD 20705, USA e-mail: fhashem@asrr.arsusda.gov, Tel.: +001-301-5045736, Fax: +001-301-5045728
  • A. I. Mohamed
    • Agricultural Research Station, Virginia State University, Petersburg, VA 21806, USA
  • S. M. Abdel-Wahab
    • Soil, Water and Environment Research Institute, Agricultural Research Center, Giza 12619, Egypt
  • N. I. Hegazi
    • Faculty of Agriculture, Cairo University, Giza 12619, Egypt
ORIGINAL PAPER

DOI: 10.1007/s003740050440

Cite this article as:
Hashem, F., Swelim, D., Kuykendall, L. et al. Biol Fertil Soils (1998) 27: 335. doi:10.1007/s003740050440

Abstract

Rhizobium-legume symbioses are important for their nitrogen input, but salinity and elevated temperature in arid and semi-arid areas limit their effectiveness, and therefore plant growth and productivity. Sixteen Rhizobium strains isolated from root nodules of Leucaena trees grown in different geographical areas of Egypt varied in their degree of tolerance to salinity and in their symbiotic effectiveness with Leucaena leucocephala under saline conditions. Three strains were tolerant to >3% NaCl. L. leucocephala grown in the greenhouse at concentrations of NaCl up to 1.0% and inoculated either with strain DS 78 or strain DS 158 displayed significantly better growth than those plants grown at the same levels of salinity and inoculated with reference strain TAL 583. Although nine of the Rhizobium strains grew at 42  °C, their mean generation times were lengthened two- to fourfold. When daylight growth temperatures were elevated from 30  °C to 42  °C, nodule number and mass, nitrogenase activities and shoot top dry weight of plants inoculated with strains DS 78, DS 157 and DS 158 significantly increased, whereas these parameters decreased in plants inoculated with strain TAL 583. Rhizobium strains that effectively nodulate Leucaena under adverse saline conditions and at high temperatures were thus isolated, identified and characterized.

Key words Biological nitrogen fixation Legume trees Nitrogenase activity Plant-microbe interaction

Copyright information

© Springer-Verlag Berlin Heidelberg 1998