MACNBR   00242
MUSEO ARGENTINO DE CIENCIAS NATURALES "BERNARDINO RIVADAVIA"
Unidad Ejecutora - UE
artículos
Título:
Environmental effects on grass-endophyte associations in the harsh conditions of south Patagonia.
Autor/es:
NOVAS, M.V.; COLLANTES, M.B.; CABRAL, D.
Revista:
FEMS MICROBIOLOGY ECOLOGY
Editorial:
Federation of European Microbiological Societies. Elsevier.
Referencias:
Lugar: Amsterdam; Año: 2007 vol. 61 p. 164 - 173
ISSN:
0168-6496
Resumen:
Cool-season grasses are frequently infected by Neotyphodium endophytes and this
association is often considered as a mutualistic symbiosis. We examined the
incidence of Neotyphodium in populations of Bromus setifolius, Phleum alpinum
and Poa spiciformis, native and wide-spread grasses from south Patagonia,
Argentina. The incidence of 36 populations of Bromus setifolius was studied in
association with climatic and soil variables. 31 populations of Ph. alpinum were
sampled in five different plant communities. Seventeen populations of P. spiciformis
were sampled in three different plant communities. The association between
incidence and climatic variables in Ph. alpinum and between incidence and soil
fertility in P. spiciformis was investigated. In B. setifolius endophyte incidence was
positively correlated with annual average rainfall contrary to the results found in
Ph. alpinum. All the populations of P. spiciformis were infected by endophytes and
the incidence was associated with plant community. The Neotyphodium-grass
interaction is variable in natural populations, supporting the increasing evidence
that the Neotyphodium-host interaction depends, in many cases, on the environmental
conditions. Field observations suggest that in detrimental low growth
conditions the association is not favoured, leading to a decrease in the endophyte
frequency of infection or even to the complete loss of the association.