Skip to main content
ARS Home » Plains Area » College Station, Texas » Southern Plains Agricultural Research Center » Crop Germplasm Research » Research » Publications at this Location » Publication #381329
Research Project: Identification of Resistance in Sorghum to Fungal Pathogens and Characterization of Pathogen Population Structure

Location: Crop Germplasm Research

Title: SNPs that identify alleles with highest effect on grain mold ratings after inoculation with Alternaria alternata or with a mixture of Alternaria alternata, Fusarium thapsinum, and Curvularia lunata

Author
item Prom, Louis
item AHN, EZEKIEL - Texas A&M University
item MAGILL, CLINT - Texas A&M University

Submitted to: Journal of Agricultural and Crop Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/9/2021
Publication Date: 3/30/2021
Citation: Prom, L.K., Ahn, E.J., Magill, C.W. 2021. SNPs that identify alleles with highest effect on grain mold ratings after inoculation with Alternaria alternata or with a mixture of Alternaria alternata, Fusarium thapsinum, and Curvularia lunata. Journal of Agricultural and Crop Research. 9(3):72-79.

Interpretive Summary: Globally, grain mold caused by many fungi is the most important sorghum disease and when susceptible lines are planted, yield losses can reach 100%. To determine which gene(s) contributes to grain mold resistance against either an individual fungus or mixture of fungi, over 300 lines from the Sorghum Association Panel (SAP) were tested in the field. The results showed that some of the SAP lines possess genes that play a role in host defense. This work is significant because it suggests that these lines have potential for use in breeding, as well as for future tests to verify a role for these genes in active host defense.

Technical Abstract: In a recent study, sorghum association panel (SAP) lines were evaluated for grain mold resistance against Alternaria alternata individually and when co-inoculated with Fusarium thapsinum, and Curvularia lunata. A genome-wide association study based strictly on mold rating scores for each SAP line revealed a number of SNPs closely linked or in genes known to play roles in host defense. In that analysis mold ratings were used directly, without accounting for how much change was made in each rating versus water treated controls. Here, the same datasets for mold scores and more than 79,000 SNP alleles were used, but the untreated control values for each cultivar were subtracted from the treated sample ratings. The new dataset is thus designed to identify host genes that had the most impact in changing the mold rating over background. Our goal was to determine if the same genes would be identified, and if not, did the functions of the new genes also make them candidates for roles in mold resistance. As before, when the newly found top-scoring SNPs were mapped to the published sorghum genome, the nearest annotated gene has precedence for a role in host defense.