Generation and characterization of Brassica rapa ssp. pekinensis - B. oleracea var. capitata monosomic and disomic alien addition lines.

Five monosomic alien addition lines (MAALs) of Brassica rapa ssp. pekinensis - B. oleracea var. capitata were obtained by hybridization and backcrossing between B. rapa ssp. pekinensis (female parent) and B. oleracea var. capitata. The alien linkage groups were identified using 42 B. oleracea var. capitata linkage group-specific markers as B. oleracea linkage groups C2, C3, C6, C7 and C8. Based on the chromosomal karyotype of root tip cells, these five MAALs added individual chromosomes from B. oleracea var. capitata: chr 1 (the longest), chr 2 or 3, chr 5 (small locus of 25S rDNA), chr 7 (satellite-carrying) and chr 9 (the shortest). Five disomic alien addition lines were then generated by selfing their corresponding MAALs.