Tetraploid turnips: towards autopolyploid Brassica crops

四倍体萝卜：走向同源多倍体芸苔属作物

• 批准号: 427946057
• 负责人: Professorin Dr. Annaliese Mason
• 金额: --
• 依托单位: Professur Pflanzenzüchtung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/427946057?language=en
• 关键词: Tetraploid; turnips; towards; autopolyploid; Brassica

Natural polyploid species often show greater environmental tolerances than their progenitor diploid species. As well, polyploids usually have larger cell and organ sizes than diploids. Hence, induced polyploidy, where chromosome numbers within a species are artificially doubled, has great potential for plant breeding, particularly of root and vegetable crops. In turnip (diploid Brassica rapa) and related vegetable species, targeted breeding efforts in the 1970s and 80s resulted in the successful release of a number of tetraploid crop types. However, these polyploid induction breeding strategies were hindered by problems such as poor fertility and vigour, and were subsequently abandoned. I propose to use modern genotyping, sequencing and cytogenetics technologies to identify the factors responsible for success and failure of induced polyploidy breeding in these crops, investigating successful tetraploid cultivars and creating novel tetraploid material from different genotypes and with different degrees of homozygosity and divergence between subgenomes. I will test the hypotheses that 1) greater genetic divergence between subgenomes in a tetraploid results in greater stability and hybrid vigour, 2) that genetic variation exists for genomic stability at the tetraploid level, and 3) that “double-cross” hybrids (resulting from an F1 by F1 cross at the tetraploid level) will show greater hybrid vigour than normal F1 hybrids. Such hybrids have immense potential for yield improvement as a result of increased heterosis, if stable tetraploid crop types can be created on demand.

天然多倍体物种往往比其祖先二倍体物种表现出更大的环境耐受性。同样，多倍体通常比二倍体具有更大的细胞和器官尺寸。因此，诱导多倍体，其中一个物种内的染色体数目人工加倍，具有很大的潜力，植物育种，特别是根和蔬菜作物。在芜菁（二倍体芜菁）和相关蔬菜物种中，20世纪70年代和80年代的定向育种努力导致了许多四倍体作物类型的成功释放。然而，这些多倍体诱导育种策略受到诸如育性和活力差等问题的阻碍，随后被放弃。我建议使用现代基因分型，测序和细胞遗传学技术，以确定在这些作物中诱导多倍体育种的成功和失败的因素，调查成功的四倍体品种和创造新的四倍体材料从不同的基因型和不同程度的纯合性和亚基因组之间的分歧。我将检验以下假设：1）四倍体中亚基因组之间更大的遗传差异导致更大的稳定性和杂种优势，2）在四倍体水平上存在基因组稳定性的遗传变异，以及3）“双交”杂种（由四倍体水平上的F1与F1杂交产生）将显示出比正常F1杂种更大的杂种优势。如果能按需创造稳定的四倍体作物类型，这种杂交种由于增加的杂种优势而具有巨大的增产潜力。