Sweet sorghum (Sorghum bicolor L. Moench) is a promising bioenergy crop. To increase the productivity of this crop, marker-assisted breeding will be important to advance its genetic improvement. The objective of this study was to identify quantitative trait loci (QTL) associated with several bioenergy-related traits in sweet sorghum that include owering time, plant height, total biomass, stem diameter, stem moisture percentage, and brix. We used 188 F 7 recombinant inbred lines (RILs) derived from a cross between a sweet sorghum (Wray) and a grain sorghum (Macia). The RILs and their parental lines were grown at two locations. Genotyping-by-sequencing analysis of the RILs allowed for the construction of a map with 979 single nucleotide polymorphisms. Using the inclusive composite interval mapping of additive QTL, a major QTL for owering time was detected on chromosome 6, and explained 29.45% of the phenotypic variances (PVE). Major QTL for plant height (29.51% PVE) and total biomass yield (16.46% PVE) were detected on chromosome 7, and QTL for stem diameter (9.43% PVE) were detected on chromosome 1. Several QTL for brix were associated with sugar transporter genes, providing candidate genes for further study. For example, a major QTL for brix (39.92% PVE) was detected on chromosome 3 consistently across four environments. In total, 21 QTL for ve traits were detected across four environments using ICIM-ADD. The identi ed QTL in this study should aid in the development of lines and hybrids of sorghum that are suitable for the production of bioenergy.

Sweet sorghum (Sorghum bicolor L. Moench) is a promising bioenergy crop. To increase the productivity of this crop, marker-assisted breeding will be important to advance its genetic improvement. The objective of this study was to identify quantitative trait loci (QTL) associated with several bioenergy-related traits in sweet sorghum that include flowering time, plant height, total biomass, stem diameter, stem moisture percentage, and brix. We used 188 F7 recombinant inbred lines (RILs) derived from a cross between a sweet sorghum (Wray) and a grain sorghum (Macia). The RILs and their parental lines were grown at two locations. Genotyping-by-sequencing analysis of the RILs allowed for the construction of a map with 979 single nucleotide polymorphisms. Using the inclusive composite interval mapping of additive QTL, a major QTL for flowering time was detected on chromosome 6, and explained 29.45% of the phenotypic variances (PVE). Major QTL for plant height (29.51% PVE) and total biomass yield (16.46% PVE) were detected on chromosome 7, and QTL for stem diameter (9.43% PVE) were detected on chromosome 1. Several QTL for brix were associated with sugar transporter genes, providing candidate genes for further study. For example, a major QTL for brix (39.92% PVE) was detected on chromosome 3 consistently across four environments. In total, 21 QTL for five traits were detected across four environments using ICIM-ADD. The identified QTL in this study should aid in the development of lines and hybrids of sorghum that are suitable for the production of bioenergy.