Selection indices application to improve tall fescue synthetic varieties for yield and quality traits in Ardebil province

Breeding based on selection indices is an effective method for improved varieties. In order to study simultaneous selection for forage yield and quality traits in tall fescue (Festuca arundinacea Schreb), through selection indices, 36 populations were sown using a triple lattice design in Ardebil, Iran during 2006. data were collected for heading date, plant height, dry matter (DM) yield, dry matter digestibility (DMD), water soluble carbohydrates (WSC), crude protein (CP), acid detergent fiber (ADF) and total ash over two years. The estimates of broad sense heritability (h2b) were moderate to high for all of traits except for CP and total ash. DMD was positively correlated with WSC, while the genetic correlation among ADF with both DMD and WSC was negative. Heading date was negatively correlated with both DM yield and plant height. The relationships between DM yield with both DMD and WSC were weak and non significant. Using phenotypic and genotypic variance and covariance matrices and broad sense heritability as the relative economic value, selection indices were estimated. The results indicated that selection based on all of the traits would make more gain. The highest selection indices were obtained for the populations 1317, 60065 (Simirom), 60075, 60083 (Tavankesh), 782026 (Shahrekord), VIII (Russia), 1081(Palestine) and 1414 (Australia). They could be used as the parents of new synthetic varieties.