PREDICT: Omics-based models for prediction of hybrid performance in oilseed rape

杂种优势是提高异交作物产量的重要现象。在甘蓝型油菜（Brassica napus L.）中，杂交品种今天占据了国际种子市场的主要份额。然而，与玉米等其他重要杂交作物相比，油菜的产量杂种优势水平相对较低。因此，油菜育种行业对更优地利用杂种优势以提高杂交性能有相当大的兴趣。本项目旨在建立基于组学的油菜优质杂交种种子产量杂种优势预测模型。将通过比较大量优秀亲本系的DNA序列、代谢物和转录组数据，以及来自其F1后代发育表型和田间产量评估的综合信息，开发和测试杂交性能预测模型。全基因组单核苷酸多态性（SNP）基因分型将使用新的甘油三酯60k SNP Infinium阵列实现，而转录组学、代谢组学和表型分析将分别利用最新的mRNA测序、质谱和高通量表型技术。从先前的观察中得出的基本假设是，发育和产量杂种优势受到共同调节因素的影响，这些因素的特定等位基因组合，以及它们引发的代谢物和基因表达谱，与杂种优势的改善有关。我们的目标是确定“组学选择”概况，以及相应的分析和统计方法，这些方法可以通过预先选择具有最高潜力的新杂交组合来简化育种过程。基因组学、转录组学或代谢组学预测因子的鉴定将进一步支持我们对油菜杂种优势表现的分子过程和机制的理解。通过与德国两家领先的杂交油菜品种生产商（Norddeutsche Pflanzenzucht Hans-Georg Lembke KG和Deutsche Saatveredelung AG）合作，我们将把对基础和高价值植物育种过程的基础研究转化为具有强大商业潜力的杂交育种改进系统。

Heterosis, or hybrid vigour, is an important phenomenon for improving the yield performance of outcrossing crops. In oilseed rape (Brassica napus L.), hybrids today make up the major share of the international seed market. However, in comparison to other important hybrid crops like maize, oilseed rape shows relatively low levels of yield heterosis. The oilseed rape breeding industry therefore has considerable interest in a more optimal utilisation of heterosis for improvement of hybrid performance. The aim of this project is to develop omics-based prediction models for seed yield heterosis in elite oilseed rape hybrids. Models for prediction of hybrid performance will be developed and tested by comparing DNA sequence, metabolite and transcriptome data from a large set of elite parental lines with comprehensive information from developmental phenotyping and field-based yield evaluations of their F1 offspring. Genome-wide single-nucleotide polymorphism (SNP) genotyping will be achieved using the new B. napus 60k SNP Infinium array, while the transcriptomic, metabolomic and phenomic analyses will take advantage of the latest mRNA sequencing, mass-spectrometry and high-throughput phenotyping technologies, respectively. The underlying hypothesis, derived from previous observations, is that developmental and yield heterosis are influenced by common regulatory factors and that specific allelic combinations of these factors, together with the metabolite and gene expression profiles they elicit, are associated with improved heterosis. We aim to identify an "omics selection" profile, along with corresponding analytical and statistical methods, that can together be used to streamline breeding processes by pre-selecting parental lines with highest potential for top performing new hybrid combinations. Identification of genomic, transcriptomic, or metabolomic predictors will furthermore support the advancement in our understanding of the molecular processes and mechanisms involved in heterosis manifestation in oilseed rape. By collaborating with two leading German producers of hybrid oilseed rape varieties (Norddeutsche Pflanzenzucht Hans-Georg Lembke KG and Deutsche Saatveredelung AG) we will transfer basic research on a fundamental and high-value plant breeding process into a system with a strong commercial potential for improvement of hybrid breeding.