Diallel and Path Coefficient Analysis of Tall Fescue (Festuca Arundinacea) Regrowth Under Controlled Conditions

Relationships among leaf elongation rate, leaf width, leaf area expansion rate, number of tillers/plant, and net CO2 exchange (NCE) with total forage yield/plant of tall fescue, Festuca arundinacea Schreb., were studied in a controlled environmental chamber. Among progeny of a 6 × 6 diallel, number of tillers/plant was correlated highly significantly (1% level) with total forage yield/plant (r = 0.697). Path coefficient analyses showed that both tillers/plant and yield/tiller had large positive direct effects on total yield/plant. Utilizing a diallel analysis it was found that additive genetic effects were most important for all traits except for NCE. Progenies did not differ significantly for NCE. Nonadditive genetic effects, although of less magnitude than additive effects, were also found to be important for number of tillers/plant and yield/tiller. Highest broad sense heritabilities were found for number of tillers/plant, yield/tiller, and yield/plant with values of 69, 66, and 66%, respectively