Construction of an evenly-distributed genetic map using contig-tag-SNPs for quantitative trait loci (QTL) analysis of fiber-related traits in kenaf (Hibiscus cannabinus L.)

Kenaf is one of the most important natural fiber crops worldwide, which aims at harvesting bast fiber. Mining QTL loci of fiber yield and quality traits will facilitate fiber improvement and molecular marker-assisted breeding in kenaf. In this study, Fuhong 952 and Zanyin No. 1 were used as parents to construct two mapping populations, F-2 and F-2:3, and an evenly distributed genetic linkage map was constructed by re-sequencing. The map contains 2512 contig-tag-SNP markers, and 18 linkage groups with a total length of 1287.63 cM and an average distance of 0.51 cM. Totally, 32 and 28 QTLs were detected in the F-2 and F-2:3 populations, respectively. Through Blast searching against the reference genome using the sequences of flanking molecular markers linked to QTLs, 374 candidate genes related to cell wall formation and photoperiod regulating flowering were found in these loci, including cellulose synthase-like genes, MYB genes, and Agamous-like genes. These findings could lay a foundation for the improvement of fiber-related traits and gene cloning in kenaf.