MAGIC maize populations for corn improvement
Dissecting the architecture of complex traits into Mendelian loci and identifying the causal genes are still limiting steps on the path of crop improvement. Linkage mapping in biparental populations or association mapping on diversity panels restrict our ability to discover specific genetic determinants in a single mapping study. The availability of populations with high genetic diversity and recombination density overcomes the limitation of either approach. Multi-parent cross designs (MpCD) bridge the advantages of either approaches and dramatically increase mapping resolution and power by incorporating greater genetic diversity and by increasing the number of crossing generations.
We have produced the first balanced multi-parental population in maize, a tool that provides high diversity and dense recombination events to improve our understanding of the genetic basis of quantitative traits and guide predictive crop breeding.
A total of 1,636 MAGIC maize recombinant inbred lines were derived from eight genetically diverse founder lines. Their genomes are evenly differentiated mosaics of the eight founders, with mapping power and resolution strengthened by high minor allele frequencies and a fast decay of linkage disequilibrium. We demonstrate MAGIC maize's value in identifying the genetic bases of complex traits of agronomic relevance by illustrating the case-studies for grain yield and flowering time.
Dell'Acqua et al (2015) Genetic properties of the MAGIC maize population: a new platform for high definition QTL mapping in Zea mays. Genome Biology 16:167
Holland et al (2015) MAGIC maize: a new resource for plant genetics. Genome Biology 16:163