Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, No,2 Xudong 2nd Rd, 430062 Wuhan, China.
BMC Plant Biol. 2013 Sep 24;13:141. doi: 10.1186/1471-2229-13-141.
The genetics and molecular biology of sesame has only recently begun to be studied even though sesame is an important oil seed crop. A high-density genetic map for sesame has not been published yet due to a lack of sufficient molecular markers. Specific length amplified fragment sequencing (SLAF-seq) is a recently developed high-resolution strategy for large-scale de novo SNP discovery and genotyping. SLAF-seq was employed in this study to obtain sufficient markers to construct a high-density genetic map for sesame.
In total, 28.21 Gb of data containing 201,488,285 pair-end reads was obtained after sequencing. The average coverage for each SLAF marker was 23.48-fold in the male parent, 23.38-fold in the female parent, and 14.46-fold average in each F2 individual. In total, 71,793 high-quality SLAFs were detected of which 3,673 SLAFs were polymorphic and 1,272 of the polymorphic markers met the requirements for use in the construction of a genetic map. The final map included 1,233 markers on the 15 linkage groups (LGs) and was 1,474.87 cM in length with an average distance of 1.20 cM between adjacent markers. To our knowledge, this map is the densest genetic linkage map to date for sesame. 'SNP_only' markers accounted for 87.51% of the markers on the map. A total of 205 markers on the map showed significant (P < 0.05) segregation distortion.
We report here the first high-density genetic map for sesame. The map was constructed using an F2 population and the SLAF-seq approach, which allowed the efficient development of a large number of polymorphic markers in a short time. Results of this study will not only provide a platform for gene/QTL fine mapping, map-based gene isolation, and molecular breeding for sesame, but will also serve as a reference for positioning sequence scaffolds on a physical map, to assist in the process of assembling the sesame genome sequence.
尽管芝麻是一种重要的油料作物，但芝麻的遗传学和分子生物学直到最近才开始研究。由于缺乏足够的分子标记，尚未公布芝麻的高密度遗传图谱。特异长度扩增片段测序（SLAF-seq）是一种新开发的用于大规模从头 SNP 发现和基因分型的高分辨率策略。本研究采用 SLAF-seq 方法获得足够的标记，构建芝麻高密度遗传图谱。
测序共获得 28.21Gb 数据，包含 201,488,285 对末端 reads。在雄性亲本中，每个 SLAF 标记的平均覆盖度为 23.48 倍，在雌性亲本中为 23.38 倍，在每个 F2 个体中为 14.46 倍的平均覆盖度。共检测到 71,793 个高质量 SLAF，其中 3,673 个 SLAF 具有多态性，1,272 个多态性标记符合遗传图谱构建要求。最终图谱包括 15 个连锁群（LGs）上的 1,233 个标记，图谱总长度为 1,474.87cM，相邻标记之间的平均距离为 1.20cM。据我们所知，这是迄今为止芝麻最密集的遗传连锁图谱。图谱上的' SNP_only'标记占 87.51%。图谱上共有 205 个标记表现出显著（P < 0.05）的分离扭曲。
本研究首次报道了芝麻高密度遗传图谱。该图谱是利用 F2 群体和 SLAF-seq 方法构建的，该方法允许在短时间内高效开发大量多态性标记。本研究的结果不仅为芝麻基因/QTL 精细定位、图谱定位基因克隆和分子育种提供了一个平台，而且还为物理图谱上序列支架的定位提供了参考，有助于组装芝麻基因组序列。
