High-resolution genetic map construction and QTL analysis of important fiber traits in kenaf using RAD-seq

Quantitative trait locus (QTL) mapping is a useful method for revealing the mechanism of complex genetic traits and identifying new genomic information to accelerate crop improvement. In the present study, 154 F2:3 strains and their parents were used for restriction site-associated DNA sequencing, single-nucleotide polymorphism (SNP) identification, and genetic map construction. After filtering based on stringent filtering standards, 297.5 Gb of clean data were obtained. Further, 5,191 polymorphic SNP markers were identified from each sample, of which 1,997 polymorphic SNP markers were successfully mapped onto 18 different linkage groups. Six QTLs (QPH, QFBW, QDBW, QFW, QFT, and QFC) were identified based on the genetic map using the multiple QTL mapping (MQM) method, which were then assigned to three linkage groups, LG16, LG8, and LG3. QPH, QFBW, QDBW, and QFW were related to fiber yield, while QFT and QFC were related to fiber quality. This is the first study of its kind to map QTL of fiber yield and fiber quality, which will facilitate further understanding of the molecular genetic basis of these traits. However, there are limitations regarding the utilization of this map because several large gaps remain in some linkage groups. Therefore, additional markers need to be developed to further narrow these regions.