Biodiversity and symbiotic efficiency of indigenous rhizobia nodulating field pea

Abstract

The main aim of this study was to assess genetic diversity within the natural populations of field pea rhizobia on different field sites in Northwestern Croatia and to evaluate their symbiotic efficiency. Identification of related bacterial strains was carried out using RAPD and rep-PCR methods and on the basis of differences in the nodulation nodD gene region by PCR-RFLP method. Indigenous strains have been shown to differ significantly from each other as well as from the reference strains Rhizobium leguminosarum bv. viciae used in these study. Based on the nodulation genes, it was found that most isolates have the same or very similar nodulation nodD region except the isolates K22 and K23. A greenhouse studie was performed for evaluation of symbiotic efficiency of strains. The highest nodule dry weight was determined by inoculation with strains K23, K22, K17 and K20, indicating their high infectivity and nodulation ability. Significantly higher green mass and dry matter yield in abouveground plant parts were determined by inoculation with two indigenous strains K26 and K16 that showed potentially high symbiotic efficiency compared to other tested strains.

Keywords

• biological nitrogen fixation
• rhizobia
• field pea
• genetic diversity