Symbiotic interactions between chickpea (Cicer arietinum L.) genotypes and Mesorhizobium strains

Legume genotype (GL) x rhizobium genotype (GR) interaction in chickpea was studied using a genetically diverse set of accessions and rhizobium strains in modified Leonard Jars. A subset of effective GL x GR combinations was subsequently evaluated in a pot experiment to identify combinations of chickpea genotypes and rhizobium strains with stable and superior symbiotic performance. A linear mixed model was employed to analyse the occurrence of GL x GR interaction and an additive main effects and multiplicative interaction (AMMI) model was used to study patterns in the performance of genotype-strain combinations. We found statistically significant interaction in jars in terms of symbiotic effectiveness that was entirely due to the inclusion of one of the genotypes, ICC6263. No interaction was found in a subsequent pot experiment. The presence of two genetic groups (Kabuli and Desi genepools) did not affect interaction with Mesorhizobium strains. With the exception of a negative interaction with genotype ICC6263 in the jar experiment, the type strain Mesorhizobium ciceri LMG 14989 outperformed or equalled other strains on all chickpea genotypes in both jar and pot experiments. Similar to earlier reports in common bean, our results suggest that efforts to find more effective strains may be more rewarding than aiming for identification of superior combinations of strains and genotypes.