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

• Applicant: Professor Dr. Heiko Becker
• Subject Area: Plant Breeding and Plant Pathology
• Term: from 2003 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5403783

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.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1149: Heterosis in Plants