|PATIL, NIKHIL - Texas A&M University
|Klein, Robert - Bob
|WILLIAMS, CRESCENDA - Texas A&M University
|COLLINS, S. DELROY - Texas A&M University
|Knoll, Joseph - Joe
|BURRELL, A. MILLIE - Texas A&M University
|Anderson, William - Bill
|ROONEY, WILLIAM - Texas A&M University
|KLEIN, PATRICIA - Texas A&M University
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/21/2016
Publication Date: 2/16/2017
Citation: Patil, N.Y., Klein, R.R., Williams, C., Collins, S., Knoll, J.E., Burrell, A., Anderson, W.F., Rooney, W.J., Klein, P.E. 2017. Quantitative trait loci associated with anthracnose resistance in sorghum. Crop Science. 57:877-890. https://doi.org/10.2135/cropsci2016.09.0793.
Interpretive Summary: A wealth of genetic diversity and valuable traits exist in sorghum germplasm, in particular genetic resistance to fungal pathogens. Foliar diseases in sorghum can reduce grain yield in temperate and tropical environments, especially under wet, humid conditions. To provide geneticists in the U.S. with new sources of disease resistance for fungal pathogens, we identified regions of sorghum chromosomes that harbor genes that make sorghum plants more tolerant to specific sorghum diseases. These genetic studies represent success in locating chromosome regions that condition disease resistance, which will aid in the development of higher-producing sorghum varieties for farmers in the U.S. and worldwide.
Technical Abstract: With an aim to develop a durable resistance to the fungal disease anthracnose, two unique genetic sources of resistance were selected to create genetic mapping populations to identify regions of the sorghum genome that encode anthracnose resistance. A series of quantitative trait loci were identified that conferred variable levels of resistance, and three encoded stable resistance across all environments while two loci were environment specific. A major anthracnose resistance QTL on chromosome 9 was observed in all environments and, depending on the environment, controlled from 19-to-62% of the phenotypic variance. An additional major QTL on chromosome 5 genome explained from 20-to-39% of the phenotypic variance and was observed in four of the six environments tested. A series of environment-dependent resistance loci were also observed, which likely reflected the unique environmental and disease pressure that existed in each location. Each of these trait loci represents targets for marker-assisted introgression of durable anthracnose resistance into elite sorghum inbreds. Resequencing of the genomes of resistance cultivars SC155 and SC414 facilitated a preliminary survey of the coding region sequences of genes annotated as playing a role in host defense. The resequenced genomes of the resistant genotypes and the linkage mapping resources represent information relevant for more detailed molecular characterization of genes conditioning anthracnose resistance in this tropical cereal.