High Density Linkage Map and QTL Analysis of Forage Quality Traits of Switchgrass AP13xVS16 Cross

Switchgrass has huge potential as a warm season forage crop because of its high biomass production per unit area and high protein content, although it has been identified primarily as feedstock for cellulosic ethanol production by the U.S. Department of Energy. Development of genetic linkage map and association studies of the markers with phenotypes dissects the quantitative trait loci (QTL), and provide tools for MAS (Marker Assisted Selection) in molecular plant breeding program. We generated pseudo-F₁ population from a cross of AP13xVS16 and sequenced 233 genotypes from this population using GBS approach. We identified 455,999 haplotype SNP markers and developed high density genetic linkage map for 18 linkage group using 378 to 2,270 high quality SNP markers for each of the linkage group. Forage quality traits data such as protein, lignin, dry matter, ADF, NDF, TDN, dNDF48 and IVTDMD were collected for these genotypes using NIRS (Near Infra-Red Spectroscopy) methodology. We observed significant variations among these traits within and across locations. Associations of these traits with SNP markers are being carried out. Detail of the linkage mapping and QTL analysis will be presented in the poster.