Radish, Raphanus sativus L., is an annual vegetable of the family Cruciferae. Radish has RR genome with 18 somatic chromosome numbers (2n=2x=18). Until now, detailed karyotypic analysis is not only constructed only by conventional staining techniques but also other method. Fluorescence in situ hybridization (FISH) is a powerful molecular cytogenetic technique using chromosomal markers that reveal the positions of specific genes, such as ribosomal DNAs, thereby making it easy to identify individual chromosomes. We have constructed detailed karyotypes of four different local and wild varieties of radish, based on the chromosome arm length and fluorescence in situ hybridization (FISH) with the 45S rDNA and 5S rDNA as probes. As for the karyotype of radish, 9 pairs of chromosomes were extremely small in size with about 1 to 3 um in length at mitotic metaphase having metacentrics or submetacentrics. Three pairs of 45S rDNA signals and two pairs of 5S rDNA signals were observed in four radish species. One pair of 45S rDNA signal was located on terminal region of short arm chromosome, while two pairs were in interstitial region. Two pairs of 5S rDNA signals were located on interstitial region of chromosome. In conclusion, it was feasible to identify the radish by karyotype and physical mapping analyzed using ribosomal DNA.

• Yoon-Jung Hwang(Department of Horticultural Science, Kyungpook National University)
• Jeong-Hwan Mun(Department of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration)
• Hee-Ju Yu(Department of Life Sciences, The Catholic University of Korea)
• Ki-Byung Lim(Department of Horticultural Science, Kyungpook National University) Corresponding Author