Endophyte status in summer-dormant tall fescue in the southern Great Plains of USA

摘要

Non-toxic fungal cndophytes provide persistence-related benefits to summer-active, continental-type tall fescue (Festuca amndinacea Schreb.), as well as reduced animal toxicosis compared to toxic endophytes. However, the benefits of fungal endophytesto summer-dormant, Mediterranean-type tall fescue persistence or production are unclear. Summer-dormant tall fescue has potential to replace traditional, annual small grain graze-out systems in the Southern Great Plains region of the USA. This region ischaracterized by severe water deficits accompanied by extreme heat in summer, and by relatively mild, rainy winters (Malinowski et al. 2009). Summer-active tall fescues are better suited to high rainfall areas (>900 mm annual average rainfall (AAR)) east of the 97° longitudinal meridian, while summer-dormant tall fescues are best adapted to lower rainfall ireas (600 to 900 mm AAR) between the 97° and 99° longitudinal meridian (Butler et al. 2011).