Genetic control of sorghum resistance to leaf anthracnose

Abstract

A study was carried out to investigate the inheritance of resistance to anthracnose, caused by Colletotrichum sublineolum , in sorghum. Crosses between resistant and susceptible parents and backcrosses between F 1 plants and the susceptible parents were carried out under field conditions. The F 1 generations and the segregant populations were evaluated under artificial inoculation conditions in the greenhouse. In the F 1 generation of all crosses with the respective isolates, all of the plants presented a resistance reaction except for the F 1 plants resulting from the BR009 × SC283 cross. In the F 2 generation, the frequencies of resistant and susceptible plants conformed to the hypothesis that one gene with two alleles controls host resistance, except in one cross. Out of the eight backcrosses, six presented segregation that corresponded to the hypothesis formulated. For most crosses, resistance was dominant, and the proportions of resistant and susceptible plants in the segregant populations conformed to the frequencies expected under the hypothesis of gene‐for‐gene resistance and dominant gene action.