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ARS Home » Southeast Area » Mayaguez, Puerto Rico » Tropical Crops and Germplasm Research » Research » Publications at this Location » Publication #410167
Research Project: Uncovering New Sources of Disease Resistance in Tropical Sorghum Germplasm

Location: Tropical Crops and Germplasm Research

Title: Association analysis of grain mould resistance in a core collection of NPGS Ethiopian sorghum germplasm

Author
item Cuevas, Hugo
item Prom, Louis

Submitted to: Plant Genetic Resources
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/21/2024
Publication Date: 5/22/2024
Citation: Cuevas, H.E., Prom, L.K. 2024. Association analysis of grain mould resistance in a core collection of NPGS Ethiopian sorghum germplasm. Plant Genetic Resources. https://doi.org/10.1017/S1479262124000157.
DOI: https://doi.org/10.1017/S1479262124000157

Interpretive Summary: The NPGS Ethiopian sorghum core collection of the USDA is an important source of genetic diversity for the development of new sorghum varieties. Therefore, a total of 330 accessions from this core collection were evaluated for grain mold resistance across four tropical environments. Five accessions with resistance response were identified. Genome-wide association analysis identified three DNA regions associated with grain mold resistance that enclose candidate resistance genes. These five NPGS Ethiopian accessions are useful in a pre-breeding germplasm program to develop new improved germplasm with novel sources of grain mold resistance.

Technical Abstract: The Ethiopian core collection of the USDA-Agriculture Research Service, National Plant Germplasm System (NPGS) includes 376 accessions and a genomic characterization that revealed 151,210 single nucleotide polymorphisms (SNPs). This collection, however, lacks phenotypic characterization for several important agriculture traits. A total of 330 accessions from this NPGS Ethiopian core set were evaluated for grain mold resistance response across four tropical environments. Most of the accessions in the NPGS Ethiopian collection showed susceptibility to grain mold based on the low emergence rate and high seed deterioration observed in the seeds. The population structure of the collection was not related to grain mold resistance response suggesting this germplasm originated in regions with low disease pressure. The analysis identified two accessions with high emergence (PI 457867 and PI 454221) and three (PI 455036, PI 455213, and PI 330821) with low seed degradation. Genome-wide association analysis found genomic regions in chromosome 1, 3, and 8 associated with the observed grain mold resistance variation. Candidate gene analysis within these three loci identified diseases resistance genes involved in pathogen recognition and signaling cascades of the plant immunity system. These five NPGS Ethiopian accessions are candidates for use in a pre-breeding germplasm program to develop improved germplasm with novel sources of grain mold resistance.