chapter  Chapter 47
9 Pages

Stress Tolerance of Endophyte-Infected Turfgrass

WithMichael D. Richardson, Charles W. Bacon

Traditional approaches used to confront abiotic stresses such as inadequate water and fertility include supplementary irrigation and soil mineral additives. The exploitation of a mutualistic symbiosis between fungal endophytes and certain turfgrass species offers a new approach in reducing damage which results from abiotic stress. The differential growth response of endophyte-infected grasses to nitrogen fertilization, as well as the abundance of nitrogen-rich intermediates arising from fungal metabolism, suggests that basic nitrogen metabolism in the host plant is altered by this symbiosis. Nitrogen nutrition also plays a role in seedling growth of endophyte-infected tall fescue and perennial ryegrass. Infected seedlings were less vigorous than endophyte-free seedlings at low nitrogen levels, but more vigorous when nitrogen was in excess. The regulation of water loss in endophyte-infected grasses by leaf rolling has been reported in several studies comparing cloned genotypes of tall fescue.