Location: Genomics and Gene Discovery
Title: Genetic Linkage Mapping and Segregation Distortion in a Three-Generation Four-Founder Population of Panicum vigatum (L.) Authors
|Li, Guifen -|
|Serba, Desalegn -|
|Saha, Malay -|
|Bouton, Joseph -|
Submitted to: Genes, Genomes, and Genomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 13, 2014
Publication Date: March 18, 2014
Citation: Li, G., Serba, D.D., Saha, M.C., Bouton, J.H., Lanzatella-Craig, C., Tobias, C.M. 2014. Genetic Linkage Mapping and Segregation Distortion in a Three-Generation Four-Founder Population of Panicum vigatum (L.). Genes, Genomes, and Genomics. doi:10.1534/g3.113.010165. Interpretive Summary: This linkage mapping study was conducted in order to allow identification of genetic regions controlling biomass traits such as yield and cell wall composition in switchgrass. Having a three-generation pedigree simplifies identification of these regions by giving prior knowledge of what markers and traits are physically located on the same chromosome segment.
Technical Abstract: Switchgrass (Panicum virgatum L.), a warm season, C4, perennial grass, is one of the predominant grass species of the North American tall grass prairies. It is viewed as a high-potential bioenergy feedstock species because it can produce large amounts of lignocellulosic material with relatively few inputs. The objectives of this project were to develop an advanced switchgrass population and use it for the construction of genetic linkage maps and trait characterization. A three-generation, four-founder population was created and a total of 188 progeny of this advanced population were genotyped that included a mixture of self-pollinated and hybrid individuals. The female map integrated both sub-populations and covered 1,629 cM of the switchgrass genome with an average map length of 91 cM per linkage group. The male map of the hybrid progeny covered 1,462 cM with an average map length of 81 cM per linkage group. Average marker density of the female and male maps was 3.9 and 3.5 cM per marker interval, respectively. Based on the parental maps the genome length of switchgrass was estimated to be 1,776 cM and 1,596 cM for the female and male map, respectively. The proportion of the genome within 5 cM of a mapped locus was estimated to be 92% and 93% for the female and male maps, respectively. Thus, the linkage maps have covered most of the switchgrass genome. The assessment of marker transmission ratio distortion found that 17.6% of the single dose markers were distorted from the expected 1:1 Mendelian segregation. Several distorter loci were found distributed throughout the genome with linkage groups Ib-m and VIIIa-f most affected.