Abiotic Stresses and Endophyte Effects
- David P. Belesky and
- Charles P. West
Abiotic stresses consist of nonorganismal, nonpathogenic factors that inhibit plant function. Tall fescue [Lolium arundinaceum (Schreb.) Darbysh.] is widely symbiotic with a naturally occurring endophytic fungus [Neotyphodium coenophialum (Morgan-Jones and Gams) Glenn, Bacon, and Hanlin], which confers many benefits to its host that favor its ecological fitness for growth, persistence, and reproduction. Tolerance or resistance to water deficit (drought) and soil chemical stresses, such as low pH and low mineral availabilities, comprise the two principal categories of abiotic stresses. Enhanced tolerances of tall fescue to such stresses due to endophyte symbiosis are not universally expressed, and the mechanisms by which the symbiosis imparts such benefits are not well understood. Plant responses to endophytes involve a complex of physiological, biochemical, and morphologic adjustments that are conditioned by host genotype, endophyte genotype, environment, and their interactions. Endophyte strains that lack ergot-alkaloid production capability have been discovered recently, culminating the 30-yr search for ways to combat the deleterious effects of wild endophytes in Lolium species. When some of these novel endophytes are transferred into elite tall fescue germplasm, host plant persistence and vigor are enhanced. These innovations will allow grassland managers to exploit the agronomic benefits, while avoiding the detrimental aspects of the tall fescue–endophyte symbiosis, for profitable livestock production.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 2009. American Society of Agronomy, Crop Science Society of America, Soil Science Society of America, 5585 Guilford Road, Madison, WI 53711-5801, USA. Tall Fescue for the Twenty-first Century. H.A. Fribourg, D.B. Hannaway, and C.P. West (ed.)