Karyotype analysis and molecular markers identification of radish (Raphanus sativus L.) germplasm

In order to obtain precise cyto-genetic information in radish, karyotypes of 11 radish accessions by a root-tip squashing method were investigated and the germplasm was also identified using RAPD and SRAP molecular markers. The results showed that all the accessions were diploid (2n=18); the chromosomes mainly consisted of metacentric and submetacentric chromosomes, and satellites were found in three germplasms. The karyotype belonged to 1A or 2A and the relative length of chromosome varies from 8.16 to 14.43%. The asymmetry index ranged from 55.39 to 59.48%, indicating that there was relative similarity of karyotype among the different germplasm. The UPGMA cluster analysis showed that the 11 germplasms were much related and the similarity coefficient was between 0.66 and 0.79. The radish cultivars of same root skin color were mostly clustered into a group, which indicated that taproot shin color would play an important role in radish classification. 'Nau-tjwq', 'Nau-dzh2' and 'Nau-qyh' which had satellites could not cluster together with the germplasms of the same root skin color, indicating that satellite was very important for germplasm identification.