Location: Crop Germplasm Research
Title: Heritability and quantitative trait loci of composition and structural characteristics in sorghum grainAuthor
PATIL, NIKHIL - Texas A&M University | |
PUGH, NICHOLAS - Texas A&M University | |
Klein, Robert - Bob | |
MARTINEZ, HECTOR - Texas A&M University | |
MARTINEZ, RAUL - Texas A&M University | |
RODRIGUEZ-HERRERA, RAUL - Universidad Autonoma De Coahuila | |
ROONEY, WILLIAM - Texas A&M University | |
KLEIN, PATRICIA - Texas A&M University |
Submitted to: Journal of Crop Improvement
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/10/2018 Publication Date: 1/1/2019 Citation: Patil, N., Pugh, N., Klein, R.R., Martinez, H., Martinez, R., Rodriguez-Herrera, R., Rooney, W., Klein, P. 2019. Heritability and quantitative trait loci of composition and structural characteristics in sorghum grain. Journal of Crop Improvement. 33(1):1-24. https://doi.org/10.1080/15427528.2018.1536006. DOI: https://doi.org/10.1080/15427528.2018.1536006 Interpretive Summary: Major advancements in science hinge on understanding the location of genes controlling traits that are critically important to agriculture. Breeding efforts in cereal crops directed towards developing or improving end-use products of grain require assessment of existing trait variance and an understanding of the genes of grain quality traits. To provide geneticists in the U.S. with new knowledge of grain quality traits in sorghum, we identified regions of sorghum chromosomes that harbor genes that control grain fiber, protein, starch, and fat content along with chromosome region controlling grain size. These genetic studies represent success in locating chromosome regions that control sorghum grain quality traits, which will aid in the development of specialty food varieties for farmers in the U.S. and worldwide. Technical Abstract: Breeding efforts in cereal crops directed towards developing or improving end-use products of grain require assessment of existing phenotypic variance and an understanding of the genetic control of grain quality traits. To this end, a grain sorghum mapping population was evaluated in multiple environments for grain composition content (fat, fiber, protein, starch) using near-infrared reflectance spectroscopy, and size estimates of grain parts (embryo, vitreous endosperm, floury endosperm, kernel area) using an image-based phenotyping software system. Estimates of broad-sense heritability of grain compositional traits ranged from 0.11 to 0.90 while those of grain size ranged from 0.16 to 0.72. Composite interval mapping was applied to a SNP-based linkage map to identify marker-trait associations, and through these efforts, a total of 37 Quantitative Trait Loci for grain quality were identified across environments. Each trait loci explained between 7-23% of the phenotypic variation for a given grain trait. Three of the five trait loci that co-localized were for traits with significant negative correlation, which included grain protein content that was negatively correlated with grain starch content. In addition, several traits that were positively correlated (e.g., fat and fiber content), also revealed co-localized trait loci. These results provide a unique set of trait loci not reported earlier, which depending on their position and effect, are potential candidates for improving grain quality via marker-assisted selection. |