Rapeseed as a model to analyse `fixed heterosis` in allopolyploid plants

同种异体多倍体（allopolyploidy）在植物进化中起着重要的作用。异体多倍体成功的一个主要原因是同源染色体上基因之间的良好相互作用（“固定”杂种优势）。固定杂种优势可能在二倍体物种中也很重要，因为即使在许多二倍体中，大的基因组片段也是重复的。油菜（AACC基因组）是一个非常适合分析“固定”杂种优势的模型系统，因为它可以很容易地从二倍体亲本种芜菁、菜籽（AA）和白菜（CC）中培育出人工“再合成”系。因此，将创建一种材料，它在等位基因贡献上完全平衡，但在杂合性（纯合与杂合）、倍性（二倍体与四倍体）和基因组多样性（同源四倍体与异源四倍体）的数量上有所不同。在本材料中，多倍体、“固定”杂种优势和由于杂合性而产生的“经典”杂种优势的重要性将从表型上分析营养生物量生产。这种材料将为详细分析“经典”和“固定”杂种优势的分子、生化和生理原因提供独特的可能性。

The spontaneous hybridisation of related species by combining their genomes (allopolyploidy) has played a prominent role in plant evolution. A main reason for the success of allopolyploids are the favourable interactions between genes on their homeologous chromosomes ('fixed' heterosis). Fixed heterosis is probably also important in diploid species because even in many diploids large genome segments are duplicated. Rapeseed (AACC genome) is a very suitable model system to analyse 'fixed' heterosis because artificial 'resynthesized' lines can be easily developed from the diploid parental species turnip rapeseed (AA) and cabbage (CC). Therefore a material will be created, which is completely balanced in the allelic contributions, but differs in the amount of heterozygosity (homozygous vs. heterozygous), ploidy (diploid vs. tetraploid) and genomic diversity (autotetraploid vs. allotetraploid). In this material, the importance of polyploidy, 'fixed' heterosis and 'classical' heterosis due to heterozygosity will be analysed phenotypically for vegetative biomass production. This material will provide unique possibilities for a detailed analysis of the molecular, biochemical and physiological causes of 'classical' and 'fixed' heterosis.