Description
The asexual Epichloë fungal endophytes that form mutualistic, obligate, asymptomatic associations with ryegrasses (Lolium spp.) and tall fescue (Festuca arundinacea) are critical components of pastures in the USA, Australia and New Zealand. Research has convincingly demonstrated that these endophytes enhance agronomic performance of their grass hosts, due to protection from biotic and abiotic stresses such as insect pests and drought. However, although beneficial in terms of enhancing forage quantity, the widespread occurrence of ‘common-toxic’ strains of endophyte negatively impacts the quality of forage for livestock. These bioprotective and anti-quality properties are due to endophyte-expressed secondary metabolites. It has been reported globally that a range of livestock species suffer from clinical and sub-clinical effects of commontoxic endophytes. Production losses of milk and meat can be high, along with significant effects on animal welfare from ryegrass staggers and heat stress. These detrimental effects on livestock are most prevalent, and are of greatest economic importance, in North and South America for tall fescue, and in Australia and New Zealand for ryegrass. An additional consideration is whether secondary metabolites consumed by animals are present in animal products and if so, does this impact human health. Endophyte toxin residues have been detected in animal fat and milk but their presence is highly unlikely to pose a threat to human health. The discovery and sowing of selected endophytes in elite cultivars offers a path for farmers to gain the agronomic benefits of endophyte with no or greatly reduced animal toxicity.
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
A Global Perspective of Epichloë Endophyte Toxicity in Sown Pastures
The asexual Epichloë fungal endophytes that form mutualistic, obligate, asymptomatic associations with ryegrasses (Lolium spp.) and tall fescue (Festuca arundinacea) are critical components of pastures in the USA, Australia and New Zealand. Research has convincingly demonstrated that these endophytes enhance agronomic performance of their grass hosts, due to protection from biotic and abiotic stresses such as insect pests and drought. However, although beneficial in terms of enhancing forage quantity, the widespread occurrence of ‘common-toxic’ strains of endophyte negatively impacts the quality of forage for livestock. These bioprotective and anti-quality properties are due to endophyte-expressed secondary metabolites. It has been reported globally that a range of livestock species suffer from clinical and sub-clinical effects of commontoxic endophytes. Production losses of milk and meat can be high, along with significant effects on animal welfare from ryegrass staggers and heat stress. These detrimental effects on livestock are most prevalent, and are of greatest economic importance, in North and South America for tall fescue, and in Australia and New Zealand for ryegrass. An additional consideration is whether secondary metabolites consumed by animals are present in animal products and if so, does this impact human health. Endophyte toxin residues have been detected in animal fat and milk but their presence is highly unlikely to pose a threat to human health. The discovery and sowing of selected endophytes in elite cultivars offers a path for farmers to gain the agronomic benefits of endophyte with no or greatly reduced animal toxicity.
