Fungal Endophyte does not Enhance Cold Tolerance of Tall Fescue

Authors: Casler, Michael; VAN SANTAN, E - AUBURN UNIVERSITY

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/28/2008
Publication Date: 9/22/2008
Citation: Casler, M.D., Van Santan, E. 2008. Fungal Endophyte does not Enhance Cold Tolerance of Tall Fescue. Crop Science. 48:2033-2039.

Interpretive Summary: Tall fescue has historically been of minor importance to livestock agriculture in cooler regions of the temperate zone. As its use in these regions expands, it becomes increasingly important to understand the effect of infection by the fungus that lives within the plant. We created infected and uninfected populations of four tall fescue varieties and compared them in two experiments in Wisconsin. Both experiments clearly demonstrated the fungal endophyte has no effect on cold tolerance of tall fescue. Forage producers will benefit from this information, knowing that they need not waste money on purchasing tall fescue seed with expensive novel-endophyte technology for northern regions in which cold is the most important environmental stress.

Technical Abstract: Tall fescue (Lolium arundinaceum) has historically been of minor importance to livestock agriculture in cooler regions of the temperate zone. As its use in these regions expands, it becomes increasingly important to understand the effect of infection by its fungal endophyte (Neotyphodium coenophialum) on agronomic fitness of tall fescue. Our objective was to determine the effect of endophyte infection on forage yield and survival of tall fescue under field conditions in which freezing temperatures, combined with lack of persistent snow cover, represent the most significant stress factor. In experiment 1, we evaluated 427 half-sib familes of four base populations, half endophyte-infected (E+) and half endophyte-free (E-), for forage yield and survival. There was no effect of endophyte on either forage yield or survival, despite complete stand loss of one population during two winters. In experiment 2, we evaluated 640 clones of confirmed endophyte status, half E+ and half E-, for survival under two management regimes at four Wisconsin locations. Nearly all mortality occurred during the first winter, with a small additional amount of mortality during the second winter. There was no effect of endophyte infection on plant mortality. Similar to experiment 1, one population suffered complete mortality during the first two winters of experiment 2. We conclude that the fungal endophyte has no effect on cold tolerance of tall fescue.