Genetic Analysis in Advanced Backcross Populations of Brassica oleracea

The single species Brassica oleracea has great economic importance, remarkable morphological variation and genome complexity. To understand the genetics of morphological diversity within the species and dissect its complex genome, two backcross populations were developed by using inbred lines of cabbage (Badger Inbred) and cauliflower (Orange) as donor parents, and a rapid cycling line (TO1434) as the recurrent parent. Genotypes of the two populations were determined in the BC₄F₁ generation by genotyping-by-sequencing (GBS). The two populations were evaluated in the field for five seasons. Morphological traits, including flower color and leaf-, stem-, and flower-traits, were segregating within the two populations, which allowed us to identify putative QTLs. The two populations provide the foundation to construct panels of near isogenic lines covering most of the genome, finely map QTLs for morphological traits, and improve sensitivity to small effect QTLs in the near future.