AN EVALUATION OF DISEASE RESISTANT CLONES OF BROMUS INERMIS (LEYSS.) AS BREEDING STOCKS

Seven clones of smooth bromegrass (Bromus inermis Leyss.), five of which were resistant to diseases caused by Pyrenophora bromi (Dred.) and Selenophoma bromigena (Sacc.), were crossed in all combinations forming a 7 × 7 diallel. Plants of both the F 1 and its reciprocal cross, as well as the parents, were grown in the field at Edmonton and were measured for dry matter production, plant diameter, days to head emergence and plant height during their 2nd yr. Highly significant variation due to general and specific combining ability were recorded for all the traits. Four of the disease-resistant clones were low yielding and small in plant diameter. On the basis of general combining ability effects these same clones showed little promise as parents. However, one of the disease-resistant clones, B42, was found to perform relatively well and should be of value as a breeding stock.