EFFECT .OF SOIL SALINITY ON SURVIVAL AND PERFORMANCE OF ALFALFA RHIZOBIA | ||
| Journal of Soil Sciences and Agricultural Engineering | ||
| Article 7, Volume 28, Issue 5, May 2003, Pages 4169-4182 PDF (1.63 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/jssae.2003.244619 | ||
| Authors | ||
| R. A. Abdel Aziz,; F. N. Barakah | ||
| Department of Soil ScIence, College of Agriculture, K n9 Saud University, Riyadh, Saudi Arabia | ||
| Abstract | ||
| The effect of salt stress on the growth and sUl"lival of fou introduced Sinorhizobium me/ifoti strains in the rhizosphere of alfalfa Medicago sativa L. was studied. Response to inoculation with these strains and the competition among them and against native rhizobia were investigated in two salt affected soils ith different salt concentrations of 10 and 36 dS m", Results showed thai none of th introduced rhizobial strains was affected by the soil salinity up 10 36 dS m' as they ere abte to grow and survtve in the rhizosphere of alfalfa plants. However. nodule formation by both native and introduced rhizobial slrains was negatively affe,ted by salt concentration. This indicates thai the first step in nodule formation is extremely sensitive to salinity. likely due 10 Ihe effect of salinity on the root infection sites but not on the survival of rhizobia. Acetylene reduction of nodulated roots at'd nitrogen accumulation were adversely affected by salt concentration in the soil. This may show the negative effect of salt stress on plant growth and subsequently nod Ie function. Patterns of rhizosphere COlonization by the introduced rhizobia! straims declined markedly with increased salt concentration of the soil. Data show;d thai the' introduced rhlzoblal strains could grow. survive and fix nitrogen at salt concentrations inhibitory to the growth of alfalfa. Therefore, we recommend that the futur~ studies on . the effect of salinity on symbiotic N2 fixation should focus more on aspects related to the symbiosis rather than the study of each separate partner. | ||
| Keywords | ||
| Alfalfa. N:z-fixation; nodulation. saline soils; om petition; survival of rhizobia | ||
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