Growth and symbiotic performance of faba bean inoculated with Rhizobium leguminosarum biovar viciae strains tolerant to salt

Strain GRA19 of Rhizobium leguminosarum biovar. viciae was found to be tolerant to low levels of salt (50 mM) by comparing growth under stress conditions to that in the absence of stress. Growth and symbiotic N-2 fixation (acetylene reduction activity) under saline conditions of the faba bean (Vicia faba L.) cultivar Alameda inoculated with GRA19 were reduced. Salinity significantly decreased shoot and root dry weight, nodule dry weight, and average individual nodule dry weight. Nitrogen fixation was more severely affected by salinity than plant growth and nodulation. Evidence presented here suggests the need for selecting faba bean cultivars that are tolerant to salt stress for breeding programs in order to improve the symbiotic performance of R. leguminosarum biovar. viciae.