Hokkaido Agricultural Research Center, National Agricultural Research Organization, Sapporo, 062-8555, Japan.
Mol Genet Genomics. 2019 Jun;294(3):729-737. doi: 10.1007/s00438-019-01542-2. Epub 2019 Mar 14.
The domestication of cultivated crops from their wild relatives narrowed down their genetic diversity in a bottleneck effect. Subsequently, the cultivation areas of crops have expanded all over the world into various environmental conditions from the original area along with human migration after domestication. Here, we demonstrated the genetic changes in the adaptation of rice to Hokkaido (41°2-45°3N latitude), Japan, from the tropics of their origin in Asian cultivated rice, Oryza sativa L. Although cultivated rice originated from the tropics, Hokkaido is one of the northern-limits of rice cultivation worldwide. Population genomics focusing on the local populations showed the varieties had genetically distinct classes with limited genetic diversity. In addition, some varieties in the class carried unique genotypes for flowering time, exhibiting extremely early flowering time. Certain mutations in unique genotypes can split off the varieties that are able to grow in Hokkaido. Furthermore, the changes in the genotype for flowering time during rice cultivation in Hokkaido demonstrated novel combinations of genes for flowering time owing to the intensive artificial selection on natural variation and rice breeding programs to achieve stable rice production in Hokkaido.
农作物从野生亲缘种的驯化过程导致其遗传多样性在瓶颈效应中缩小。随后，随着人类驯化后的迁移，农作物的种植区域从最初的地区扩展到世界各地的各种环境条件。在这里，我们展示了水稻适应日本北海道（北纬 41°2-45°3）的遗传变化，日本的北海道是全球水稻种植的最北限之一。以当地种群为重点的群体遗传学研究表明，这些品种具有遗传上明显不同的类群，遗传多样性有限。此外，某些类群中的品种具有独特的开花时间基因型，表现出极早的开花时间。某些独特基因型的突变可以使能够在北海道生长的品种发生分化。此外，在北海道种植水稻过程中，开花时间基因型的变化表明，由于对自然变异的强化人工选择和水稻育种种群的选择，导致了开花时间基因的新组合，从而实现了在北海道稳定的水稻生产。
