Construction of a High-Density Genetic Linkage Map and QTL Analysis of Fiber Yield Traits in Kenaf (Hibiscus Cannabinus L.) via SLAF-seq

High-density genetic maps are vital for quantitative trait loci (QTL) mapping, genome assembly, and marker-assisted selection (MAS) in plants. Meanwhile, kenaf (Hibiscus cannabinus L.) is an important crop that produces raw fiber to many industries. However, both high-density genetic map construction and QTL identification have been limited in this crop due to insufficient molecular markers. Here, we constructed a high-density genetic linkage map in kenaf via specific-locus amplified fragment sequencing (SLAF-seq). An F-7:8 mapping population of 138 recombinant inbred lines was developed by crossing between Alian and Fuhong 992. In total, 220,484 high-quality SLAFs were detected, among which 52,832 were polymorphic; 4,167 polymorphic markers were then utilized to construct a genetic map. The assembled genetic map contained 18 linkage groups, spanning 1,952.68 cM with a mean distance of 0.47 cM among the adjacent markers. Phenotypic data from 10 fiber yield-related traits were used for QTL analysis, and a total of 85 QTLs were detected for 10 traits. We were able to construct the densest linkage map yet reported in kenaf and our findings will aid in further QTL mapping, genome comparisons, and MAS breeding in kenaf.