IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
artículos
Título:
Neotyphodium fungal endophyte prevents seed germination at low water potential in Lolium multiflorum.
Autor/es:
GUNDEL, P.E.; MASEDA, P.; VILA-AIUB, M.M.; GHERSA, C.M. AND R. BENECH-ARNOLD
Revista:
ANNALS OF BOTANY
Editorial:
Academic Press
Referencias:
Lugar: Londres, Inglaterra; Año: 2006 vol. 97 p. 571 - 577
ISSN:
0305-7364
Resumen:
_ Background and Aims Temperate endophyte-infected (Neotyphodium sp.) grasses have been shown to exhibit an
ecological advantage over endophyte-uninfected grasses under abiotic stressful conditions. It is predicted that
endophyte-infected plant populations will display higher rates of germination and proportion of germinated
seeds under limiting water conditions.
_ Methods The hydrotime regression model was used to describe the effect of Neotyphodium endophyte on seed
germination of Lolium multiflorum at different water potentials. Additionally, seed mortality after water stress
exposure was estimated in endophyte-infected and -uninfected seeds.
_ Key Results Endophyte infection inhibited seed germination at all water potentials. The hydrotime model described
satisfactorily the germination responses, and revealed that endophyte-free seeds exhibited higher rates of and final
percentage germination, probably due to a lower base water potential compared with endophyte-infected seeds.
However, Neotyphodium endophyte conferred a higher rate of survival in those seeds that remained ungerminated
when exposed to highly water stress conditions.
_ Conclusions Changes produced by Neotyphodium endophyte in L. multiflorum seeds might affect fitness in
particular ecological scenarios. For example, the presence of the endophyte may curtail seed germination when
water is limiting, reducing the risk of seedling death. Conversely, endophyte-free seeds would display an enhanced
germination, ensuring a more rapid seedling establishment if later water conditions do not restrict plant growth.