Inheritance of resistance of three sorghum lines to pathotypes of Colletotrichum sublineola, causal agent of anthracnose

Authors: Prom, Louis; Cuevas, Hugo; PERUMAL, RAMASAMY - Kansas State University; ISAKEIT, THOMAS - Texas A&M University; MAGILL, CLINT - Texas A&M University

Submitted to: Plant Pathology Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2018
Publication Date: 11/1/2018
Citation: Prom, L.K., Cuevas, H.E., Perumal, R., Isakeit, T., Magill, C. 2018. Inheritance of resistance of three sorghum lines to pathotypes of Colletotrichum sublineola, causal agent of anthracnose. Plant Pathology Journal. 17(2):75-79. https://doi.org/10.3923/ppj.2018.75.79.
DOI: https://doi.org/10.3923/ppj.2018.75.79

Interpretive Summary: Anthracnose is one the most common fungal diseases of sorghum and can cause yield losses of up to 100% in infected fields. Populations obtained from crosses between three resistant sorghum lines (BTx378, PI570726 and PI569979) with a susceptible line (PI609251) showed that anthracnose resistance in BTx378 is controlled by a single dominant gene. Thus, resistance in sorghum line BTx378 will be more desirable for use in breeding for anthracnose resistance, especially in sorghum hybrid production.

Technical Abstract: Anthracnose incited by Colletotrichum sublineola is the most important foliar disease of sorghum worldwide. The hyper-variable nature of the pathogen requires continual evaluations of sorghum germplasm to identify sources with different resistance genes. Thus, this research was undertaken to determine the inheritance of two Sudanese lines PI570726 and PI569979 to pathotype 30, and BTx378 (Redlan) to pathotypes 30 (P30) and 35 (P35) of the anthracnose pathogen. Crosses between these three sorghum lines and a susceptible parent PI609251 were performed, and the resulting F2 populations were evaluated in greenhouse. Individual plants from each cross were scored according to Prom et al. (2009) disease assessment method. Chi-square test for the F2 populations of BTx378 x PI609251 against P30 and P35, segregated in the expected Mendelian ratio 3 (resistant): 1(susceptible) fashion, indicating that resistance in BTx378 to P30 and P35 of C. sublineola obtained from the USA is governed by a single dominant gene. Segregation analysis for the PI569979 x PI609251 and PI570726 x PI609251 F2 populations revealed 1:3 ratio of resistance to susceptible, indicating that resistance in PI569979 and PI570726 to P30 is conditioned by a recessive trait. Resistance in the sorghum line BTx378 was shown to be dominant and will therefore be more desirable for use in breeding for anthracnose resistance, especially in sorghum hybrid production.