Comparative study of growth parameters on diaspores and seedlings between populations of Bromus setifolius from Patagonia, differing in Neotyphodium endophyte infection

Abstract

Bromus setifolius Presl., a native perennial grass, is widely spread in the harsh environment of Patagonia, Argentina. This grass can be associated with Neotyphodium Glenn, Bacon et Hanlin endophytes which are related to aerial tissues of these plants and never show external signs of infection. Endophyte presence of certain grasses improves abiotic and biotic stress resistance, productivity or reproduction in their hosts. To compare and contrast natural populations of B. setifolius differing in endophyte infection diaspore weight of seven populations was registered. In addition, emergence and growth parameters of seedlings, dry weight, leaf length and mortality rate were measured. For this purpose, two independents assays were conducted under controlled environmental conditions, using an infected (E+) and an uninfected (E–) population in each one. Most of the analysed parameters differed between E+ and E– populations, being significantly greater in E+ populations. Populations with percentage of endophyte infection between 0% and 100% presented intermediate mean diaspore weight. These results could suggest an adaptive advantage of infected plants as a consequence of endophyte presence.