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

Abstract

Kenaf fiber extracted from kenaf stem bast is an important natural fiber. The genetic basis of fiber yield and quality is poorly understood. In the present study, Fiber yield and quality phenotypic data showed continuous positive distribution or positively skewed distribution. Fiber yield traits and its related traits including plant height, fresh bast weight, dry bast weight showed a positive correlation. However, there was a negative correlation between fiber weight and fiber count. The results showed that the fiber yield and quality agronomic traits are quantitative traits controlled by multiple genes. 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 this study, a total of 1,997 polymorphic SNP markers were successfully mapped onto 18 different linkage groups. Meanwhile six QTLs were identified based on the genetic map using the multiple QTL mapping (MQM) method, which were assigned to three linkage groups, LG16, LG8, and LG3. QTL-Plant hight, QTL-Fresh bast weight, QTL-Dry bast weight and QTL-fiber weight were related to fiber yield, while QTL-fiber strength and QTL-fiber count 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.