IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Linking the grass-endophyte symbiosis to symbiotic nitrogen-fixing bacteria of legumes and ecosystem processes
Autor/es:
GARCIA PARISI, PA; GRIMOLDI, A; LATTANZI, F; OMACINI, M.
Lugar:
Cracovia
Reunión:
Congreso; 7th International Symbiosis Society Congress; 2012
Institución organizadora:
International Symbiosis Society
Resumen:
There is currently much interest in understanding how symbiosis affects ecosystems functioning, but few studies have evaluated how ecosystem processes change in response to multiple symbioses. Asexual endophytic fungi (Neotyphodium spp, Clavicipitaceae) often inhabit healthy aerial tissues of cool-season grasses, conferring benefits such as biotic and abiotic stress tolerance, growth enhancement, and increased reproductive success. Our aims were (1) to identify the impact of the grass-endophyte symbiosis on the relationship between a neighbouring legume and its nitrogen-fixing symbiont, and (2) to assess the effect of both symbioses on the aboveground net primary productivity (NPP). We performed an outdoors experiment in N-limited microcosms where 4 plants of the legume Trifolium repens (Tr) grew surrounded by 16 plants of the annual grass Lolium multiflorum (Lm). Tr seeds were either inoculated with Rhizobium leguminosarum or not, while Lm plants presented high or low proportion of endophyte-symbiotic individuals (Lm+ or Lm- respectively). Lm+ plants reduced the number of nodules in Tr plants (LRT, ÷22=6.38, p=0.04), but did not affect the amount of nitrogen fixed (Anova, Endophyte: F1,20=0.22, p=0.64). However, the apparent transfer of fixed nitrogen from the legume to the grass was slightly higher in Lm+ than Lm- plants (F1,20=28.77, p