Genome-wide patterns of heterotic vigour associated with allopolyploid chromosome collision

与异源多倍体染色体碰撞相关的杂种优势全基因组模式

• 批准号: 410826419
• 负责人: Professor Dr. Rod Snowdon
• 金额: --
• 依托单位: Lehrstuhl für 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 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/410826419?language=en
• 关键词: Genome; wide; patterns; heterotic; vigour

Rapeseed (Brassica napus), a young allopolyploid species with limited genetic diversity, is a major oil crop in both China and Germany. In order to broaden the genetic basis available for breeding, interspecific crosses between related Brassica species are frequently performed to generate synthetic B. napus forms. The genome collision in the first meiosis of synthetic B. napus hybrids results in significant genomic alterations, but remarkable heterosis can be observed in crosses between some synthetic forms and natural B. napus. We hypothesize that dominance effects driven by beneficial genome alterations can promote heterotic potential of synthetic B. napus, and that specific genomic patterns of heterotic vigour are associated with allopolyploid chromosome collision. Modern genome analysis techniques present new opportunities to investigate and exploit structural genome variation associated with crop performance traits. In this proposal we will generate and combine unique genomic and phenomic datasets associated with advanced progenies from crosses between highly contrasting natural and synthetic B. napus parental lines, along with high-quality reference genome assemblies that illuminate structural genome variation between the parents and their F1 hybrid. Building on a long-standing cooperation between leading Chinese and German rapeseed research groups, we propose a multi-dimensional "omics" approach to investigate the basis of heterosis in this cross, which shows unusually strong heterotic vigour under both German and Chinese growing conditions. Initially we will evaluate heterotic patterns of the F1 in comparison to its synthetic and natural B. napus parents (grown in contrasting environments in Germany and China), based on integrated analysis of structural rearrangements determined from high-quality whole-genome assemblies in the context of regulatory (mRNA, miRNA) and epigenetic (whole-genome bisulfite) modifications. Secondly, we will identify quantitative trait loci (QTL) contributing to hybrid vigour in a derived F2 population, with field phenotyping in both countries and genotyping-by-sequencing for projection of QTL onto the assembled genomes of the two parents accompanied by analysis in the context of structural, regulatory and epigenetic features in the original parents and their F1. Finally we will comprehensively compare the data with other resequencing and epigenetic datasets previously generated by the two partners. The overall aim is to assess how genome structural variants impact methylation patterns, miRNA and mRNA expression and their association with heterosis in highly divergent allopolyploid parents. Besides facilitating a general understanding of how genome evolution and the hybrid advantage of complex polyploids is driven by chromosome collision and its association with heterosis, the results will also provide highly novel insights for future production of high-yielding rapeseed hybrids in China, Germany and worldwide.

Rapeseed（Brassica Napus）是一种遗传多样性有限的年轻同多倍体物种，在中国和德国都是主要的石油作物。为了扩大可用于育种的遗传基础，经常进行相关木制物种之间的种间杂交以产生合成的B. napus形式。合成B. Napus杂交的第一个减数分裂中的基因组碰撞会导致重大的基因组改变，但在某些合成形式和天然B. Napus之间的杂交中可以观察到显着的杂种。我们假设由有益基因组改变驱动的优势效应可以促进合成B. napus的异性潜力，并且异质活化的特定基因组模式与同倍度倍体染色体碰撞有关。现代基因组分析技术为调查和利用与作物性能性状相关的结构基因组变异提供了新的机会。在该提案中，我们将生成和结合与高度对比的天然和合成B. napus亲本线之间的杂交相关的独特基因组和现象数据集，以及高质量的参考基因组组件，这些基因组组件阐明了父母及其F1混合动力之间的结构性基因组变化。在主要的中国和德国菜菜研究小组之间的长期合作的基础上，我们提出了一种多维的“ OMICS”方法，以研究该十字架的杂种基础，在德国和中国的生长条件下，这一十字架表明异常异性恋。最初，我们将根据对高质量的全基因组组件确定的结构重排的综合分析（在德国和中国的对比环境中生长），评估F1的杂种模式（在德国和中国的对比环境中生长）。其次，我们将确定在衍生的F2人群中有助于杂交活力的定量性状基因座（QTL），两国的现场表型以及逐个基因分型在两个父母的组装基因组上投影，并在两个父母的组装基因组上，并在结构，法规，法规，法规，法规和表观中的父母的分析中进行了Fimbers and Expentos Primate和Firment Fripts Freption和Fiment f.1。最后，我们将将数据与先前由两个合作伙伴生成的其他重新方程和表观遗传数据集进行全面比较。总体目的是评估基因组结构变异如何影响甲基化模式，miRNA和mRNA表达及其与高度分歧的同多酶父母中的杂种相关。除了促进对基因组进化和复杂多倍体的混合优势的一般理解外，染色体碰撞及其与杂种的关联驱动外，结果还将为未来在中国，德国，德国和全球生产高生产高产的Rapeeseed Hybrids的混合体提供高度新颖的见解。