Red clover (Trifolium pratense L.) breeding. l. Clonal evaluation of a policrossing

Fernando Ortega K.1, Rafael Galdames G.1 y Alfonso Aguilera P.1

The experiment was carried out at Carillanca Experimental Station (INIA), Temuco, Chile and it corresponds to the lirst step of a red clover (Trifolium prafense L.) breeding project. The aim of the project js to release cultivars with bettar persistency than the natianal cultivar Quiñequeli. A policross and progeny test are performed. In the presant paper information from two seasons of evaluation (1989/90 and 1990/91) of the policrossing is given, emphasizing in the sanitary performance. The leal disease of higher severity was powdery mildew (Erysiphe trifolii Grev.). Powdery mildew average severity was 33 and 18% for the first and second seasons, respectively, and there were positive correlations (r = 0,72; P < 0,01) between its severity in the two seasons. However. lar the recorded severities, it didn't have signilicant correlations (P > 0,05) with mortality, seed yield or larage yield. Average mortallty atthe end of the lirst and second seasons was 27 and 40%, respectively. It was positively correlated (P < 0,01) with virus severity and was closely related to root damage by the clover barer, Hylastinus obscurus (M.) (Coleoptera: Scolytidae), assoclated to other insects and crown rol. Sevan of the 55 evaluated plants had final mortality lower than 10 % and low severity of PM and viruses. There was a positive correlation (r = 0,45; P < 0,01) between the beginning time 01 Ilowering and the number of internodes of the main stem. This suggests the possibility of estimating the Ilowering precocity by evaluating the number of internodes.

Keywords: Trifolium pratense L., red clover, cultivars, breeding, persistency.
1 Estación Experimental Carillanca (INlA), Casilla 58-D. Temuco, Chile.