Rhizobia of chickpea from southern Portugal: symbiotic efficiency and genetic diversity

Aims: In order to evaluate differences between chickpea rhizobial populatio ns from three geographical areas in southern Portugal (Beja, Elvas and Evor a), isolates from the three regions were obtained and analysed. Methods and Results: The genetic characterization of the isolates was done by plasmid profiles and restriction analysis of the nif H gene. Symbiotic e fficiency of the isolates was also determined. Relationships between geogra phical origin, symbiotic efficiency and molecular characteristics were esta blished. Beja soil revealed a larger rhizobia population as well as the pre sence of some of the isolates with higher symbiotic efficiency values. Isol ates with a single plasmid showed a significantly higher symbiotic efficien cy. Conclusions: Genetic and phenotypic differences were detected between the n atural rhizobial populations from the three locations. Significance and Impact of the Study: The different yield potential with cu ltivars of chickpea usually obtained in the three regions of southern Portu gal could be due to their different natural rhizobial populations.