利用转录组测序开发的SSR标记进行苎麻纤维细度遗传分析

Fiber fineness is the most important factor for ramie fiber quality, and improving the ramie fineness is a problem urgently needed to be solved for ramie breeding. The genetic basis of ramie fiber fineness is very complex, for it is a quantitative character and controlled by polygene. The molecular genetic studies are relatively backward, till now, there is no genetic linkage map of ramie, let alone QTL identification. A F1 segregating population derived from a high fiber fineness ramie variety "Yushan Ma" and a low fiber fineness ramie variety "Daxian Baima" had been constructed, and 1827 expressed sequence tag-derived SSR markers had been developed by transcriptome sequencing. On this basis, the linkage map was constructed. Integrated with fiber fineness data of F1 population, the genetic effect of single locus, epistatic interactions between two loci and gene × environment interaction effects were analyzed. This study will elucidate the genetic basis of ramie fiber fineness, and provide target QTL for molecular marker-assisted breeding.

纤维细度是评价苎麻纤维品质优劣最重要的指标之一，提高苎麻纤维细度是育种工作急需解决的问题。纤维细度属于数量性状，其遗传基础较复杂。苎麻分子遗传研究还相当匮乏，至今没构建过分子标记连锁图谱，更没有进行性状的QTL分析。为了实现苎麻纤维细度的QTL分析，项目组前期采用高纤维细度苎麻品种玉山麻和低纤维细度品种达县白麻杂交构建了F1分离群体；利用苎麻转录组测序获得的序列，设计了1827个表达序列标签SSR标记。在此基础上本项目拟采用这些新开发的SSR标记；利用F1群体构建苎麻的分子标记连锁图谱；结合F1无性系群体在两年度中的纤维细度数据，分析QTL的遗传效应，双位点的上位互作效应，及QTL与环境互作效应。初步揭示苎麻纤维细度的遗传基础，为分子标记辅助选择提供目标QTL。