Symbiotic Effectiveness of native Rhizobia Associated with non-native Vicia spp. and Lathyrus spp. From Magallanes

Resumo

The species Vicia magellanica, V. nigricans and Lathyrus magellanicus are part of the natural pastures of the Magallanes region. These species belong to the Fabaceae family and should be able to establish symbiotic associations with soil bacteria and thus fix atmospheric Nitrogen. The objective of this research was to evaluate root nodules formation and to determine the specificity and symbiotic effectiveness of rhizobia isolated from Vicia sp y Lathyrus sp. under controlled conditions. Thirteen rhizobial isolates were obtained from nodules collected from these species at three sites in the Magallanes region. Genetic fingerprinting identified five distinct strains. In nodulation trials with vetch (V. atropurpurea) and grass pea (L. sativus), all strains formed nodules on grass pea but were ineffective. The strains AG-298, AG-299 and AG-300 reached the highest nodulation index in grass pea. The strains AG-298, AG-299 and AG-300 were the only ones able to form root nodules in vetch, reaching dry matter levels like uninoculated control, and were therefore classified as ineffective. Rhizobia isolated from Vicia sp. and Lathyrus sp. in Magallanes, can induce nodulation but are ineffective in fixing nitrogen in V.  atropurpurea and L. sativus.