Plant breeding aims to develop improved crop varieties. Many crops have a polyploid and often highly heterozygous genome, which may make breeding of polyploid crops a real challenge. The efficiency of traditional breeding based on crossing and selection has been improved by using marker-assisted selection (MAS), and MAS is also being applied in polyploid crops, which helps e.g. for introgression breeding. However, methods such as random mutation breeding are difficult to apply in polyploid crops because there are multiple homoeologous copies (alleles) of each gene. Genome editing technology has revolutionized mutagenesis as it enables precisely selecting targets. The genome editing tool CRISPR/Cas is especially valuable for targeted mutagenesis in polyploids, as all alleles and/or copies of a gene can be targeted at once. Even multiple genes, each with multiple alleles, may be targeted simultaneously. In addition to targeted mutagenesis, targeted replacement of undesirable alleles by desired ones may become a promising application of genome editing for the improvement of polyploid crops, in the near future. Several examples of the application of genome editing for targeted mutagenesis are described here for a range of polyploid crops, and achievements and bottlenecks are highlighted.

植物育种旨在开发改良的作物品种。许多作物具有多倍体且通常是高度杂合的基因组，这可能使多倍体作物的育种成为真正的挑战。通过使用标记辅助选择 (MAS) 提高了基于杂交和选择的传统育种的效率，并且 MAS 也被应用于多倍体作物，这有助于例如基因渗入育种。然而，随机突变育种等方法难以应用于多倍体作物，因为每个基因都有多个同源拷贝（等位基因）。基因组编辑技术彻底改变了诱变，因为它可以精确选择目标。基因组编辑工具 CRISPR/Cas 对于多倍体的靶向诱变特别有价值，因为可以同时靶向所有等位基因和/或基因拷贝。甚至多个基因，每个都有多个等位基因，可以同时靶向。除了有针对性的诱变外，在不久的将来，用所需的等位基因有针对性地替换不需要的等位基因可能成为基因组编辑改进多倍体作物的一个有前景的应用。此处描述了针对一系列多倍体作物应用基因组编辑进行靶向诱变的几个示例，并强调了成就和瓶颈。