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.

甘蓝型油菜（Brassica napus）是一种年轻的异源多倍体植物，遗传多样性有限，是中国和德国的主要油料作物。为了拓宽可用于育种的遗传基础，经常进行相关芸苔属物种之间的种间杂交以产生合成B。甘蓝型油菜合成B第一次减数分裂中的基因组碰撞。甘蓝型油菜杂种的基因组发生了显著的变异，但某些人工合成的B与天然B杂交也能产生显著的杂种优势。油菜。我们假设，有利的基因组改变驱动的显性效应可以促进合成B的杂种优势潜力。油菜，杂种优势的特定基因组模式与异源多倍体染色体碰撞有关。现代基因组分析技术为研究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。在这个建议中，我们将产生和联合收割机独特的基因组和表型数据集与先进的后代之间的高度对比的天然和合成B杂交。napus亲本系，沿着高质量的参考基因组组装，其阐明了亲本和它们的F1杂种之间的结构基因组变异。基于中德油菜研究团队的长期合作，我们提出了一个多维度的“组学”方法来研究该杂交组合的杂种优势基础，该杂交组合在德国和中国的生长条件下均表现出异常强大的杂种优势。最初，我们将评估杂种优势模式的F1相比，其合成和天然B。napus亲本（生长在德国和中国的对比环境中），基于在调控（mRNA，miRNA）和表观遗传（全基因组亚硫酸氢盐）修饰的背景下从高质量全基因组组装确定的结构重排的综合分析。其次，我们将确定数量性状基因座（QTL）有助于杂交优势在衍生的F2群体，在这两个国家和基因分型测序的领域表型QTL的投影到组装的基因组的两个父母伴随着在结构，监管和表观遗传特征的背景下，在原来的父母和他们的F1的分析。最后，我们将全面比较数据与其他重测序和表观遗传数据集先前生成的两个合作伙伴。总体目标是评估基因组结构变异如何影响甲基化模式，miRNA和mRNA表达及其与高度分化的异源多倍体亲本杂种优势的关系。除了有助于全面了解染色体碰撞如何驱动基因组进化和复杂多倍体的杂种优势及其与杂种优势的关系外，这些结果还将为中国，德国和世界范围内的高产油菜杂交种的未来生产提供非常新颖的见解。