ChileanJAR

Lotus species are very important for their interesting agricultural potential, their capacity to fix atmospheric nitrogen and adaptation to low input agricultural systems. In this study, the most utilized species in the country were used: L. corniculatus or birdsfoot trefoil; L. glaber or narrowleaf trefoil; and L. uliginosus or big trefoil. With the objective of determining the nitrogen fixation capacity and comparatively evaluating the symbiotic fixation of the different strains, a trial under controlled conditions was conducted with 68 indigenous strains of Mesorhizobium loti and Bradyrhizobium sp. (Lotus). Culture tubes with Norris and Date solution without nitrogen were utilized. Emerging seedlings were inoculated with one of the native strains and evaluated 45 days after inoculation. Plants without nitrogen and with nitrogen were utilized as controls. The plants were cultivated in a controlled environment with a photoperiod of 16:8 (light: dark), at 24º C and 70% relative humidity. Of the evaluated strains, 60% were not capable of forming nodules in the Lotus species after inoculation. For L. glaber three strains were selected as being the most efficient, corresponding to 61, 65 and 66 identified as Mesorhizobium loti. For L. uliginosus, strains 38 and 52, identified as Bradyrhizobium sp., were selected as the most effective.