Quantitative Trait Loci Mapping of Stem oBrix Content and Stem Diameter in Sorghum Recombinant Inbred Lines Using Genotype-By-Sequencing

Abstract Sweet sorghum has the ability to store sugar in its stem. Many sugar content genes have been discovered and through breeding worldwide. However, some of these genes are unstable. This study aimed to detect and validate QTL for stem oBrix content from sorghum RILs. In two seasons, QTL linked with stem brix content and related traits were examined using 139 F8RILs from a grain and sweet sorghum. A genetic linkage map with 128 SNP markers was created and several QTLs were identified. Phenotypic variation between 6.33 and 14% was identified for a given trait. Over two seasons, four QTLs for stem brix content (qBrix2-1, qBrix4-1, qBrix4-2, and qBrix10-1) and three QTLs for stem diameter (qSD1-1, qSD8-1 and qSD9-1) were detected. The detected QTL could be useful for improving stem brix content in different growing season. Furthermore, it makes a significant contribution to marker-assisted brix selection and sorghum biofuel improvement.