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ARS Home » Southeast Area » Mayaguez, Puerto Rico » Tropical Crops and Germplasm Research » Research » Publications at this Location » Publication #349495

Research Project: Evaluation and Genetic Analyses of Sorghum Genetic Resources for Key Agronomic Traits

Location: Tropical Crops and Germplasm Research

Title: Genome-wide association mapping of anthracnose (Collectotrichum sublineolun) resistance in U.S. sorghum association panel

Author
item Cuevas, Hugo
item Prom, Louis
item COOPER, ELIZABETH - Clemson University
item Ni, Xinzhi

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/16/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The productivity and profitability of sorghum [Sorghum bicolor (L.) Moench] is reduced by susceptibility to fungal diseases, such as anthracnose (Colletotrichum sublineolum). A limited number of resistant accessions are present in the temperate-adapted germplasm; other exotic sources of resistance are not currently available for breeding programs. Among 335 accessions available to breeders from a previously genotyped sorghum association panel (SAP), we found that 75 were resistant to anthracnose. A phylogenetic analysis of these accessions showed high genetic diversity and multiple resistance sources. Genome-wide association scans (GWAS) were conducted using 268,289 single-nucleotide polymorphisms (SNPs) to identify loci associated with anthracnose resistance. Using logistic regressions for binary measures of resistance responses, we identified three loci within a region on chromosome 5 that have been previously associated with three sources anthracnose resistance. A GWAS limited to Caudatum germplasm identified an association with a region on chromosome 1 and with the same previous region on chromosome 5. Candidate genes within these loci were related to R-gene families, signaling cascades and transcriptional reprogramming, suggesting that the resistance response is controlled by multiple defending mechanisms. The strategic integration of exotic resistant germplasm into the SAP is needed to identify additional rare resistance alleles via GWAS.