Selection strategies for marker-assisted backcrossing with high-throughput marker systems
Selection strategies for marker-assisted backcrossing with high-throughput marker systems
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DOI：
10.1007/s00122-011-1581-0
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发表时间：
2011-07-01
影响因子：
5.4
通讯作者：
Frisch, Matthias
中科院分区：
文献类型：
--
作者：
Herzog, Eva;Frisch, Matthias
标记辅助回交在基因渐渗中的应用仍然受到标记分析成本高的限制。高通量（HT）检测有望降低这些成本，但需要新的选择策略，以有效地实施育种计划。我们的研究的目的是调查的HT标记系统相比，单标记（SM）检测的性能，并制定最佳的选择策略标记辅助回交与HT检测。我们采用计算机模拟的遗传模型，由10条染色体的160 cM长度的显性目标基因的渐渗调查。我们发现，HT标记系统的一个主要优点是，它们可以提供具有相等间隔的标记的连锁图，而提供具有小于10 cM的高标记密度的连锁图的可能性仅在标记辅助回交中具有次要用途。一个三阶段的选择策略，结合选择的重组体在标记侧翼的目标基因与SM检测和全基因组背景选择HT标记在第一个回交世代比全基因组背景选择HT标记单独更有效。联合收割机和HT检测相结合的选择策略比仅使用HT检测的全基因组背景选择更有效。该结果是针对HT和SM测定的广泛成本比获得的。如果回交一代的群体大小是三代回交程序中BC2和BC3代群体大小的两倍，则可以实现成本的进一步显著降低。我们得出结论，选择策略相结合的SM和HT检测有可能大大提高标记辅助回交的效率和灵活性。
Application of marker-assisted backcrossing for gene introgression is still limited by the high costs of marker analysis. High-throughput (HT) assays promise to reduce these costs, but new selection strategies are required for their efficient implementation in breeding programs. The objectives of our study were to investigate the properties of HT marker systems compared to single-marker (SM) assays, and to develop optimal selection strategies for marker-assisted backcrossing with HT assays. We employed computer simulations with a genetic model consisting of 10 chromosomes of 160 cM length to investigate the introgression of a dominant target gene. We found that a major advantage of HT marker systems is that they can provide linkage maps with equally spaced markers, whereas the possibility to provide linkage maps with high marker densities smaller than 10 cM is only of secondary use in marker-assisted backcrossing. A three-stage selection strategy that combines selection for recombinants at markers flanking the target gene with SM assays and genome-wide background selection with HT markers in the first backcross generation was more efficient than genome-wide background selection with HT markers alone. Selection strategies that combine SM and HT assays were more efficient than genome-wide background selection with HT assays alone. This result was obtained for a broad range of cost ratios of HT and SM assays. A further considerable reduction of the costs could be achieved if the population size in the first backcross generation was twice the population size in generations BC2 and BC3 of a three-generation backcrossing program. We conclude that selection strategies combining SM and HT assays have the potential to greatly increase the efficiency and flexibility of marker-assisted backcrossing.