Effect of Endophyte On Growth Characteristics, Oligosaccharides, and Proline Responses in Continental and Mediterranean Tall Fescue (Lolium arundinaceum) Under Cold Temperatures.

Tall fescue’s native range encompasses a wide geographical area from the Mediterranean coasts to the high altitudes of the Alps to the northern latitudes of Sweden. This geographical range has allowed tall fescue to develop specific traits unique to those environments. Most of this diversity, like in many crops, has not been assessed.  Many traits that would improve the growth and survivability in diverse environments are only beginning to be understood and used in commercial crops.  Having continued high growth rates under cold temperatures is an important and beneficial trait for tall fescue. Additionally, oligosaccharides and proline are important to a plants’ survival under these conditions. Currently, tall fescue is a major forage crop in the U.S. where Kentucky 31 is the dominate cultivar. However, to expand the range and utility of this forage novel traits must be identified and introgressed into this crop. By introducing genes that extend the growing season further into the fall, fewer stored forages are needed by livestock operations during the winter months. To identify lines that have superior growth rates under cold temperatures, a diverse set of tall fescue accessions were obtained from GRIN. Leaf extension rates (LER) of each line were assessed in growth chambers set at 4 ^oC. The accessions with the three fastest and three slowest leaf growth rates were selected along with Kentucky 31 as a check. The LER of the fastest individual were three times greater at 4.2 mm day^-1 compared to the slowest growing individual at 1.4 mm day^-1 and Kentucky 31 was about 2.5 mm day^-1. The simple oligosaccharides were nearly double the amount in the fastest growing genotypes compared to the slowest growing genotypes.  Additionally, the proline levels were higher in the fastest growing genotypes. There appears to be great diversity regarding these traits.