Symbiotic compatibility between Rhizobium laguerreae and its host.

The efficiency of interaction between legumes and rhizobia depends on the genotypes of both partners, which may lead to inefficient symbiosis. This study examined interactions between three pea (Pisum sativum L.) genotypes and six Rhizobium laguerreae strains classified into three genospecies (gsN, gsO, gsR) via whole-genome phylogenetic analysis. The peculiarities of interaction between each pea genotype and each strain were studied at histological and ultrastructural levels. Both normally developing symbioses and those with various disruptions in the infection process, bacterial release, differentiation of bacteria into bacteroids, and the ability of bacteroids to maintain their functional activity were identified. It was shown that cv. 'Rondo' was the most successful in forming symbioses with R. laguerreae strains, in turn, strain AMPS05 was the most effective on all three pea genotypes studied. Thus, the efficiency of interaction in symbioses formed between pea and R. laguerreae strains depends on the genotypes of both partners.