The objectives of this research were to describe the variability regarding partial resistance to leaf rust in segregating populations and to study genetic control of the resistance expression. The evaluation of disease was done at 1998, 1999 and 2000, according to modified Cobb’s scale. The results of three years studies showed that regardless the great environmental effect on the expression of resistance, the segregating population presented great variability for partial resistance. The frequency distribution of AUDPC for advanced generations, was continuous for this trait, indicating the presence of several genes of small effects controlling the disease. The estimatives of herdability varied from moderate to high.
Puccinia coronata; durable resistance; quantitative resistance
