Résumé
Nitrogen nutrition of legume relies on both soil mineral N absorption and symbiotic nitrogen fixation by rhizobia and the symbiotic interaction depends on each of the partners. This study evaluates the variability of symbiotic efficiency on the growth of two cultivars of pea and lentil inoculated with 16 different rhizobial genotypes originating from sub-humid and semi-arid regions of eastern Algeria. The genotypes were defined by the combination of haplotypes characterized by rRNA intergenic spacer (IGS) and a nodulation gene marker (nodD region). Analysis of shoots, roots and nodules is an effective method to examine plants growth. The results revealed that efficiency is linked to the rhizobial genotype, effect of the strains, and host plant species. A statistically significant interaction between cultivar and rhizobial genotype was only found for nodule number, size and biomass in forage pea. With respect tothe development of tested plants, strains having genotypes originating from sub-humid zones are more effective than those originating from semi-arid zones. This functional variability is strongly linked to the genetic variability of the chromosomal ribosomal IGS. Strains isolated from lentil are more effective for lentil growth than those isolated from pea. The nitrogen content correlated with the plant growth. In conclusion, the inoculation of plants cultivated in a semi-arid soils with effective strains from a sub-humid origin is likely to be more beneficial for plants under conditions of environmental stress.