Bett Kirstin E, Lydiate Derek J
Agriculture and Agri-Food Canada, Saskatoon Research Centre, 107 Science Pl., Saskatoon, SK S7N OX2.
Genome. 2003 Jun;46(3):423-30. doi: 10.1139/g03-026.
The first genetic map of the Raphanus genome was developed based on meiosis in a hybrid between Raphanus sativus (cultivated radish) and Raphanus raphanistrum (wild radish). This hybrid was used to produce a BC1 population of 54 individuals and an F2 population of 85 individuals. A total of 236 marker loci were assayed in these populations using a set of 144 informative Brassica RFLP probes previously used for genetic mapping in other crucifer species. The genetic maps derived from the BC1 and F2 populations were perfectly collinear and were integrated to produce a robust Raphanus map. Cytological observations demonstrated strict bivalent pairing in the R. sativus x R. raphanistrum hybrids. Productive pairing along the length of each chromosome was confirmed by the identification of nine extensive linkage groups and the lack of clustering of marker loci. Indeed, the distributions of both marker loci and crossovers was more random than those reported for other crop species. The genetic markers and the reference map of Raphanus will be of considerable value for future trait mapping and marker-assisted breeding in this crop, as well as in the intergenomic transfer of Raphanus genes into Brassica crops. The future benefits of comparative mapping with Arabidopsis and Brassica species are also discussed.
基于萝卜（栽培萝卜）和野萝卜（野生萝卜）杂交种的减数分裂，绘制了第一张萝卜基因组遗传图谱。该杂交种用于产生一个由54个个体组成的回交一代群体和一个由85个个体组成的F2群体。使用一组先前用于其他十字花科物种遗传图谱构建的144个信息丰富的芸苔属限制性片段长度多态性（RFLP）探针，在这些群体中总共检测了236个标记位点。从回交一代和F2群体获得的遗传图谱完全共线，并整合在一起以产生一个可靠的萝卜图谱。细胞学观察表明，萝卜×野萝卜杂交种中存在严格的二价体配对。通过鉴定九个广泛的连锁群以及标记位点缺乏聚类，证实了每条染色体长度上的有效配对。事实上，标记位点和交叉的分布比其他作物物种报道的更为随机。萝卜的遗传标记和参考图谱对于该作物未来的性状定位和标记辅助育种，以及将萝卜基因跨基因组转移到芸苔属作物中具有重要价值。还讨论了与拟南芥和芸苔属物种进行比较作图的未来益处。
