Phenotypic and Genotypic Diversity for Tolerance to Environmental Stresses in Rhizobia Nodulating Lentil

Growth and productivity of lentil (Lens culinaris) in most of the growing areas is usually affected by different environmental stresses such as drought, extreme temperatures, soil pH, salinity and heavy metals in soils. These environmental stresses also affect biological nitrogen fixing ability of the nodulating rhozobia, thereby affecting growth and productivity of lentils.  Here, we isolated 206 rhizobia nodulating lentil from 27 sites representing different soil types in Morocco, examined their phenotypic diversity for tolerance to the above environmental stresses, performed molecular diversity analysis using rep-PCR and showed that there is a substantial phenotypic and genotypic diversity exists in the rhizobial population. Phenotypic and rep-PCR analysis revealed 23 phenotypic and 4 genotypic groups. No relationship between genotype and phenotype was observed. The isolates from different phenotypic groups were clustered in a genotypic groups, indicating no relationship between genotype and phenotypic groupings. We selected multiple stress tolerant and genetically diverse strains for studying nitrogen fixation ability and identified better N2-fixing strains for inoculation of lentil. The identified strains are being tested under field conditions.