Changes in Crown Lipid and Carbohydrate Compositions of Lolium Perenne Accessions During Cold Acclimation.

Perennial ryegrass (Lolium perenne L.) is a cool-season turfgrass species that can exhibit significant freezing injury in northern climates of the United States.  Recent breeding efforts have identified novel perennial ryegrass germplasm with superior freezing tolerance compared to many commercially available cultivars. The underlying factors responsible for these differences in freezing tolerance, however, require further investigation.  Therefore, the objectives of this study were to quantify major physiological and biochemical changes occurring during the cold acclimation period for four perennial ryegrass accessions varying in freezing tolerance (two freezing tolerant accessions, TOL-1 and TOL-2, and two freezing susceptible accessions, SUS-1 and SUS-2).