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ARS Home » Plains Area » College Station, Texas » Southern Plains Agricultural Research Center » Crop Germplasm Research » Research » Publications at this Location » Publication #370952

Research Project: Identification of Resistance in Sorghum to Fungal Pathogens and Characterization of Pathogen Population Structure

Location: Crop Germplasm Research

Title: Late growth stages of johnsongrass can act as an alternate host of Colletotrichum sublineola

Author
item AHN, EZEKIEL - TEXAS A&M UNIVERSITY
item ODVODY, GARY - TEXAS A&M UNIVERSITY
item Prom, Louis
item MAGILL, CLINT - TEXAS A&M UNIVERSITY

Submitted to: Plant Health Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/13/2020
Publication Date: 2/7/2020
Citation: Ahn, E., Odvody, G., Prom, L.K., Magill, C. 2020. Late growth stages of johnsongrass can act as an alternate host of Colletotrichum sublineola. Plant Health Progress. 21(1):60-62. https://doi.org/10.1094/PHP-11-19-0084-RS.
DOI: https://doi.org/10.1094/PHP-11-19-0084-RS

Interpretive Summary: Johnsongrass is genetically similar to sorghum, the fifth most important cereal crop worldwide. This weed is often found in most production areas, including sorghum fields, and if not controlled can cause significant yield loss to the main crop. Results showed that 19 johnsongrass were infected when treated with the sorghum anthracnose pathogen. The work is significant because it showed that johnsongrass can act as an alternate host to the pathogen and can spread the disease to sorghum plants if the weed is not controlled around production fields.

Technical Abstract: Twenty-six johnsongrass cultivars, collected from seven states of the U.S. were spray-inoculated with spores of an isolate of Colletotrichum sublineola derived from sorghum. Inoculations were made when plants reached at growth stages 2 (4-5 leaves), 3 (7-8 leaves) and 6 (post panicle emergence). At the earlier stages the johnsongrass cultivars showed hypersensitive responses and small lesions, however, acervulus formation was not observed. When late growth stage of johnsongrass plants were spray-inoculated, acervulus formation was confirmed in nineteen cultivars as early as five-days-post-inoculated. The results confirm johnsongrass can act as an alternate host of C. sublineola under favorable conditions, and growth stages of johnsongrass may be an important factor for cross infection of C. sublineola between johnsongrass and sorghum.