CHARACTERIZATION OF THE KANGAROO VALLEY ECOTYPE OF PERENNIAL RYEGRASS(LOLIUM-PERENNE)

A breeding program commenced in 1992 to produce perennial ryegrass (Lo lium perenne) cultivars based on the Kangaroo Valley perennial ryegras s (KVPR) ecotype with improved winter and late season growth, disease resistance, and persistence. Perennial ryegrass plants (9000) were col lected from 45 sites within the Kangaroo Valley and Shoalhaven flood p lain in August 1992. Using principal component: analysis, site differe nces were greatest for N percentage, Mg and Na concentration, and Al s aturation. Collections were space planted along with standard cultivar s (Banks, Ellett, Embassy, Grasslands Lincoln, and Vedette) at Berry, New South Wales (34 degrees 48'S), and Timboon, Victoria (38 degrees 3 2'S), with 50 treatments and 10 replicates. Plants were visually score d for seasonal yield, rust incidence, greenness, leafiness, persistenc e, habit, and tiller density at both sites. At Berry, leaf angle, leaf width, and heading date were determined. Despite the differences in m oisture, temperature, and growth indices between the 2 test sites, sea sonal yield scores (mean of 100 plants) at Berry and Timboon were high ly genetically correlated (r = 0.79-0.99). Standard cultivars were hig her yielding with higher tiller density but with a greater rust incide nce than collections (P < 0.01). Collections originating from the Shoa lhaven flood plain were higher yielding with greater tiller density th an plants from the Kangaroo Valley (P < 0.01), although differences we re not as great as site of origin differences would suggest. Selection s have been made for polycross half-sib formation, and half-sib evalua tion will take place at a number of sites to determine the average gen eral combining ability of parent selections for synthetic cultivar pro duction.