Inheritance of resistance to Cercosporidium personatum in groundnuts: a genetic model and its implications for selection.

In detached leaf tests with C. personatum [Mycosphaerella berkeleyi] incubation period, latent period, lesion diam., lesions/unit area and defoliation were estimated for plants of 5 F2 progenies from crosses between 2 resistant and 3 susceptible cultivars. In all progenies the first 3 variables were closely associated with one another and F2 distributions were skewed towards the mean of the susceptible parent. Genotypes for the resistant and susceptible parents are proposed. There was no evidence for genetic control of lesions/unit area, this being correlated with defoliation. Results of lab. tests with F2 progenies were compared with disease reactions of the F3 in the field. While some characters were significantly correlated, they were different for progenies of different crosses. Selection strategies are suggested