Seed functional traits in cultivars of tall fescue -Schedonorus arundinaceus- are affected by the non-toxic fungal endophyte AR584

MAILEN A. RIVEIRA RUBIN; ANDREA C. UENO; DIEGO BATLLA; LEOPOLDO J. IANNONE; MARÍA A. MARTÍNEZ-GHERSA; PEDRO E. GUNDEL

CROP & PASTURE SCIENCE

CSIRO PUBLISHING

Lugar: Collingwood; Año: 2022 vol. 76 p. 363 - 377

1836-5795

Context. Tall fescue (Schedonorus arundinaceus) is one of the most important cultivated foragegrasses in temperate regions but its association with some Epichloë fungal endophytes usuallymakes it unsuitable for livestock feeding due to toxic alkaloids. However, re-inoculation of plantswith non-toxic endophytes can result in positive effects for livestock feeding. Aims. Assess theeffects of the non-toxic AR584 endophyte on seed viability and germination in two tallfescue cultivars. Methods. The effects of AR584 endophyte (presence/absence) and tall fescuecultivar (INIA Aurora/Taita) were evaluated on seed viability and germination responses across arange of temperature and water availability regimes. Response to constant temperature andwater availability was characterised by the thermal-time and hydro-time models, respectively.Key results. Under accelerated aging conditions, endophyte presence reduced seed viability incultivar Taita. For both cultivars, endophyte-infected seeds showed a lower germination ratethan endophyte-free seeds, except for INIA Aurora under low incubation temperatures.Also, endophyte-infected seeds in both cultivars displayed lower germination rates and finalgermination as the water potential was lowered. Conclusions. A strong cultivar-by-endophyte AQ3interaction for seed germination indicates the need to understand how specific cultivarendophyte combinations best fit a given environmental condition, as defined by temperature andwater availability. Implications. The information we present can be valuable not only forfarmers who have to decide what to cultivate but also for seed companies that have to preserve seed quality.