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ARS Home » Southeast Area » Mayaguez, Puerto Rico » Tropical Crops and Germplasm Research » Research » Publications at this Location » Publication #348120

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

Location: Tropical Crops and Germplasm Research

Title: Genomic dissection of anthracnose resistance response in Sorghum bicolor (L.) Moench

Author
item Cuevas, Hugo
item CRUET, CLARA - University Of Puerto Rico
item Prom, Louis
item Knoll, Joseph - Joe
item STUTTS, LAUREN - University Of Florida
item VERMERRIS, WILFREDO - University Of Florida

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/21/2017
Publication Date: N/A
Citation: N/A

Interpretive Summary: The productivity and profitability of sorghum [Sorghum bicolor (L.) Moench] is reduced by susceptibility to fungal diseases, such as anthracnose, caused by Colletotrichum sublineolum. The identification of resistance genes is the most effective and useful strategy for disease control. This study found that inheritance of anthracnose-resistant sources present in QL3 and IS18760 is controlled by multiple loci, whereas the resistance in SC112-14 is controlled by a single locus on chromosome 5. Segregation analysis of 1,500 individuals derived from SC112-14 and association analysis using 374 exotic germplasm from Ethiopia identified the resistance gene as belonging to a family of genes encoding F-box proteins. Molecular markers developed in this study can be used for marker assisted selection in sorghum breeding to develop new broad disease-resistant varieties.

Technical Abstract: The productivity and profitability of sorghum [Sorghum bicolor (L.) Moench] is reduced by susceptibility to fungal diseases, such as anthracnose, caused by Colletotrichum sublineolum. Multiple anthracnose resistance loci have been identified in different sorghum accessions, but some of these loci only confer resistance to specific isolates of the pathogen, limiting their usefulness. Three sets of recombinant inbred lines derived from the anthracnose-resistant sources SC112-14 (Ethiopia), QL3 (India) and IS18760 (Sudan) were evaluated for anthracnose resistance response in Puerto Rico, Florida, Georgia and Texas, U.S. for two consecutive years to identify broad resistance against multiple isolates. Composite interval mapping using three high-density genetic maps constructed using genotyping by sequencing revealed that the resistance in QL3 and IS18760 is controlled by multiple loci, while the resistance in SC112-14 is controlled by a single locus on chromosome 5. Segregation analysis of 1,500 individuals derived from SC112-14 delimited this locus to a 22 kb region harboring three candidate resistance genes. Genome-wide association analysis using 374 Ethiopian accessions confirmed the region and identified the resistance gene as belonging to a family of genes encoding F-box proteins. These results indicate that this particular resistance response involves genes involved in signaling cascades and transcriptional reprograming, rather than recognition of pathotype-associated molecular patterns.