A cDNA-AFLP Based Linkage Map Constructed with 67 Loci in F 2 Population of Caixin ( Brassica rapa var. parachinensis )

A cDNA-AFLP based linkage map of Caixin ( Brassica rapa var. parachinensis ) was constructed by an F 2 population with 92 individuals from a cross of the parents of early flowering and late flowering Caixin. The fifteen selective primers generated total 229 bands with the average of 15.3 bands per primer 113 bands were polymorphic accounting for 17.5 bands per primer. The high banding primer combination was ME1M1 yielding 30 bands while the low banding primer combination was E2M5 only yielding 8 bands. The primer combination, E3M1, generated the most polymorphic bands (120), but the E1M4 and E2M5 were the least (4). Chi square test (χ 2 ) showed there was significant segregation distortion existing in the population. The linkage map was constructed based on cDNA-AFLP data, which consists of 4 linkage groups including 67 loci and spanning 334 cM with an average genetic distance of 4.99 cM.