Phenotypic characterization of rhizobia isolated from chickpea (Cicer arietinum) growing in Moroccan soils

Phenotypic characteristics of fifty-six rhizobia strains isolated from root nodules of two chickpea (Cicer arietinum L.) cultivars, growing in soils collected from different areas of Morocco, were studied. Tolerance to salinity, high temperatures, acid and alkaline pHs, heavy metals and to antibiotics as well as symbiotic and cultural characteristics allowed the description of a wide physiological diversity among tested isolates. Numerical analysis of the phenotypic characteristics showed that, below the boundary level of 82% average similarity, isolates fell into at least five distinct groups. A number of potential isolates have been identified for inoculation trials. They were effective and able to grow at pH ranging from 5 to 8, tolerated salt concentration (1-1.5%) and grew at a maximum temperature between 30 and 35 degreesC.