info:eu-repo/semantics/article
Imperfect vertical transmission of the endophyte Neotyphodium in exotic grasses in grasslands of the flooding Pampa.
Fecha
2009-12Registro en:
Gundel, Pedro Emilio; Garibaldi, Lucas Alejandro; Aragón, Myriam Roxana; Ghersa, Claudio Marco; Omacini, Marina; Imperfect vertical transmission of the endophyte Neotyphodium in exotic grasses in grasslands of the flooding Pampa.; Springer; Microbial Ecology; 57; 12-2009; 740-748
0095-3628
CONICET Digital
CONICET
Autor
Gundel, Pedro Emilio
Garibaldi, Lucas Alejandro
Aragón, Myriam Roxana
Ghersa, Claudio Marco
Omacini, Marina
Resumen
Cool-season grasses establish symbioses with vertically transmitted Neotyphodium endophytes widespread in nature. The frequency of endophyte-infected plants in closed populations (i.e., without migrations) depends on both the differential fitness between infected and non-infected plants, and the endophyte-transmission efficiency. Most studies have been focused on the first mechanism ignoring the second. Infection frequency and endophyte transmission from vegetative tissues to seeds were surveyed in two grasses growing in vegetation units that differ in flood and grazing regimes, and soil salinity. Transmission efficiency and infection frequency for tall fescue did not vary significantly and were 0.98 and 1.00, respectively. For Italian ryegrass, transmission efficiency and infection frequency were 0.88 and 0.57 in humid prairies, and 0.96 and 0.96 in the other vegetation units. Only in humid mesophytic meadows, the observed pattern was irrespective of the presence or absence of grazers. Our results suggest that selection forces for endophyte infection are different for both species. Imperfect transmission was only compensated in tall fescue through an increased fitness of infected plants. Interpreting variations of infection frequency only in terms of differential fitness can be misleading, considering that endophyte transmission can be imperfect and variable in nature. Therefore, this study highlights the importance of measuring transmission efficiency.