Evaluation of selected Ethiopian sorghum genotypes for resistance to anthracnose

Sorghum anthracnose caused by the fungal pathogen Colletotrichum sublineolum, is one of the most economically important diseases of sorghum globally and in Ethiopia. Breeding for resistance to this highly variable pathogen requires identification of new sources of resistance. Here we describe the identification of new sources of anthracnose resistance from a field-based screening of 225 landrace genotypes of sorghum collected from different parts of Ethiopia. Field trials were conducted at Assosa and Bako Agricultural research centres under natural infection to evaluate anthracnose resistance. Analysis of variance revealed significant differences in mean square due to environment, genotype and genotype by environment interactions (P ≤ 0.01) for leaf anthracnose disease relative AUDPC. Most genotypes from Western Ethiopia, a region known for high rain fall and high anthracnose disease incidence, displayed resistance reactions. Disease severity index and AUDPC showed negative correlation with agronomic, yield and yield related traits. Cluster analysis based on disease parameters suggested that accessions from neighbouring regions shared strong similarity. Seven genotypes at Bako and five genotypes at Assosa showed moderate resistance. Anthracnose resistance and better yield performance across locations were observed for three genotypes. These materials will be important for genetic studies to determine genetic control of resistance and for resistance breeding.