Skip to main content
ARS Home » Plains Area » College Station, Texas » Southern Plains Agricultural Research Center » Insect Control and Cotton Disease Research » Research » Publications at this Location » Publication #410121
Research Project: Molecular and Genetic Approaches to Manage Cotton and Sorghum Diseases

Location: Insect Control and Cotton Disease Research

Title: Genetic diversity and classification of Colletotrichum sublineola pathotypes using a standard set of sorghum differentials

Author
item Prom, Louis
item Ahn, Ezekiel
item PERUMAL, RAMASAMY - Kansas State University
item Cuevas, Hugo
item ROONEY, WILLIAM - Texas A&M University
item ISAKEIT, THOMAS - Texas A&M University
item MAGILL, CLINT - Texas A&M University

Submitted to: The Journal of Fungi
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/14/2023
Publication Date: 12/20/2023
Citation: Prom, L.K., Ahn, E.J., Perumal, R., Cuevas, H.E., Rooney, W.L., Isakeit, T.S., Magill, C.W. 2023. Genetic diversity and classification of Colletotrichum sublineola pathotypes using a standard set of sorghum differentials. The Journal of Fungi. 10(1). Article 3. https://doi.org/10.3390/jof10010003.
DOI: https://doi.org/10.3390/jof10010003

Interpretive Summary: Anthracnose on sorghum is the most damaging leaf disease of the crop, causing economic losses in the hundreds of millions of dollars annually. Although resistant lines have been reported, control of the disease can be difficult due to the existence of many different strains within the pathogen population. In this study, we examined the population structure and strains of the pathogen that exist in Georgia, North Carolina, Puerto Rico, and Texas. The work demonstrated the high genetic variation that exists for this pathogen, and led to the identification of 27 new strains. This work is significant because it shows the variability of the anthracnose pathogen and the occurrence of new strains, which will require further screening of sorghum lines to identify resistant sources that can be used by breeders and sorghum producers in the U.S. and abroad.

Technical Abstract: Sorghum anthracnose, incited by Colletotrichum sublineola, is the most destructive foliar disease, and under severe conditions, yield losses can exceed 80% on susceptible cultivars. The hyper-variable nature of the pathogen makes management challenging despite the occurrence of several resistant sources. In this study, the genetic variability and pathogenicity of 140 isolates of C. sublineola, which were sequenced using restriction site-associated sequencing (RAD-Seq), resulted in 1,244 quality SNPs. The genetic relationship based on the SNP data showed low to high genetic diversity based on the location of the isolate origin. Georgia and North Carolina isolates were grouped into multiple clusters with some level of genetic relationships to each other. Even though some Texas isolates formed a cluster, others clustered with isolates from Puerto Rico. Puerto Rico isolates showed scattered distribution, indicating the diverse nature of these isolates. Population structure and cluster analysis revealed that the genetic variation was stratified into 8 populations and one admixture group. The virulence pattern of 30 sequenced isolates on 18 sorghum differentials lines revealed 27 new pathotypes. SC748-5, SC112-14 and Brandes were resistant to all tested isolates, while BTx623 was susceptible to all. Line TAM428 was susceptible to all pathotypes, except pathotype 26. Future use of the 18 differentials employed in this study which contains cultivars/lines that have been used in the Americas, Asia, and Africa, could allow for better characterization of C. sublineola pathotypes at a global level, thus accelerating the development of sorghum lines with stable resistance to the anthracnose pathogen.