Evaluation location: Minnesota, United States
300 accessions of wild and landrace germplasm of perennial ryegrass were obtained from the National Plant Germplasm System (NPGS) of the USDA-ARS and from Rutgers University. In late August 2004, the plants were transplanted into dead sod at the St. Paul Agricultural Experiment Station, St. Paul, MN (44D,59M,23S: North and 93D,10M,28S: West), and the Sand Plains Agricultural Experiment Station, Becker, MN (45D,23M,47S: North and 93D,53M,21M: West). Soil at St. Paul is Waukegan silt loam, and soil at Becker is Hubbard loamy sand.
Data were collected on single plants as the experimental unit. In general, traits expressed on a rating scale were rated so that the highest value indicated the most beneficial phenotype for overall plant desirability. Seedling vigor was rated in early October 2004 on a 1 to 9 scale with 1 indicating the lowest vigor found, 5 indicating average vigor over the two environments, and 9 indicating the greatest vigor found. Tiller survival was rated in mid-May 2005 and 2006 on a 1 to 9 scale with 1 indicating complete death of the plant, and each incremental unit increase being equivalent to a 12.5 percentage unit increase in percent tiller survival on a whole plant basis. Spring growth was measured in mid-May 2005 and 2006 as the length of an average tiller from each plant. Summer and autumn turf quality were rated on 8 July 2005 and 23 September 2005, respectively, on a 1 to 9 scale with 1 indicating the poorest turf quality observed, 5 indicating average turf quality, and 9 indicating the best turf quality observed. Turf quality is a composite trait that includes color, leaf texture, growth habit, density of tillers, tolerance of mowing, and presence of disease as factors in overall appearance. Turf color was rated on 8 July 2005 on a 1 to 9 scale with 1 indicating the lightest green color found and 9 indicating the darkest green color found. Leaf texture was rated on 13 July 2005 on a 1 to 9 scale with 1 indicating the coarsest foliar appearance and 9 indicating the finest foliar appearance. Crown rust incidence was rated on 19 July 2005 on a 1 to 9 scale with 9 indicating no appearance of pustules, and each incremental unit decrease being equivalent to a 12.5 percentage unit increase in coverage of leaf surfaces with pustules. Growth habit was rated on 22 September 2005 on a 1 to 5 scale with 1 indicating all tillers completely prostrate and 5 indicating all tillers completely upright. Spreading vigor was rated in mid-October 2005 as plant diameter in cm.
University of Minnesota Perennial Ryegrass Breeding Web site (as of 2006).
An Excel spread sheet with the Minnesota data .