nature

当前位置: Nature » 植物学 » 正文

Sci Rep:农科院作物所张学勇研究组提出小麦单元型区段形成和演化新见解

摘要 : 2017年1月30日,国际学术权威刊物自然出版集团旗下子刊《Scientific Reports》杂志在线发表了中国农业科学院作物科学研究所作物基因资源发掘与利用创新团队张学勇研究组题为“The iselect 9K SNP analysis revealed polyploidization induced revolutionary changes and intense human selection causing strong haplotype blocks in wheat”的研究

2017年1月30日,国际学术权威刊物自然出版集团旗下子刊《Scientific Reports》杂志在线发表了中国农业科学院作物科学研究所作物基因资源发掘与利用创新团队张学勇研究组题为“The iselec 9K SNP analysis revealed polyploidization induced revolutionary changes and intense human selection causing strong haplotype blocks in wheat”的研究论文,研究发现两次多倍体化导致小麦基因在新物种和供体种之间发生革命性或颠覆性分化,驯化和育种选择导致推广品种中多样性很低的单元型区段(Haplotype Block)的形成,但几乎所有染色体两端的多样性显著提高。郝晨阳副研究员为论文第一作者,张学勇研究员为论文通讯作者。

普通小麦是异源六倍体,经历了从二倍体到四倍体(四倍体化)和四倍体到六倍体(六倍体化)两次多倍体化事件。利用9K SNP芯片(全部位于基因编码区)对小麦及其近缘种基因型分析后发现多倍体化对基因和基因组的冲击远大于驯化和遗传改良。整体而言,现代品种基因的多样性较地方品种更高,这与以往的认识是相矛盾的。造成这种现象的原因是小麦作为严格的自花授粉作物,在先民驯化、种植和选择过程中积累了大量的变异,但这些变异主要集中在基因间区和调控区,现代育种(人工杂交)促进了不同群体间基因的交流和有效重组,提高了基因的多样性。研究还发现驯化和育种对A基因组的选择明显强于B基因组,前者单元型区段数量少、但遗传跨度大,连锁不平衡更明显,A基因组拥有更多与产量性状显著关联的位点或区段,因此,提出小麦基因组进化过程中存在明显的非对称性。这项研究为海量SNP数据分析提供了参考和思路。

原文链接:

The iselec 9 K SNP analysis revealed polyploidization induced revolutionary changes and intense human selection causing strong haplotype blocks in wheat

原文摘要:

A Chinese wheat mini core collection was genotyped using the wheat 9 K iselec SNP array. Total 2420 and 2396 polymorphic SNPs were detected on the A and the B genome chromosomes, which formed 878 haplotype blocks. There were more blocks in the B genome, but the average block size was significantly (P < 0.05) smaller than those in the A genome. Intense selection (domestication and breeding) had a stronger effect on the A than on the B genome chromosomes. based on the genetic pedigrees, many blocks can be traced back to a well-known Strampelli cross, which was made one century ago. Furthermore, polyploidization of wheat (both tetraploidization and hexaploidization) induced revolutionary changes in both the A and the B genomes, with a greater increase of gene diversity compared to their diploid ancestors. Modern breeding has dramatically increased diversity in the gene coding regions, though obvious blocks were formed on most of the chromosomes in both tetraploid and hexaploid wheats. Tag-SNP markers identified in this study can be used for marker assisted selection using haplotype blocks as a wheat breeding strategy. This strategy can also be employed to facilitate genome selection in other self-pollinating crop species.

来源: Scientific Reports 浏览次数:0

热门文章TOP

RSS订阅 - 填写您的邮件地址,订阅我们的精彩内容: - 网站地图
网站联系电话:020-87540820 备案号:粤ICP备11050685号-8 增值电信业务经营许可证:粤B2-20120479
©2011-2015 生物帮 All rights reserved.