xBrassicoraphanus, a new synthetic intergeneric hybrid between Brassica rapa L. ssp. pekinensis and Raphanus sativus L., also locally known as ‘Baemoochae’, is an interesting subject for studying polyploidy and genome plasticity in the family Brassicaceae, but very few genomic and cytogenetic information. Here, we analysed the chromosome complements and pairing of the most fertile lines, BB1 and BB5, using dual-color fluorescence in situ hybridization (FISH) and genomic in situ hybridization (GISH) to check their chromosomal segregation stability. The somatic chromosome complement of B. rapa was confirmed to be 2n=20 (2.8~4.8μm), of R.sativus, 2n=18 (2.0~3.3μm), and of xBrassicoraphanus, 2n=38 (2.2~5.0μm). There were eight, eight, and seventeen metacentric pairs and two, one, and two submetacentric pairs in B. rapa, R. sativus, and xBrassicoraphanus, respectively. Additionally, three, two, and five pairs of 5S rDNA and five, three, and eight pairs of 45S rDNA were observed in B. rapa, R. sativus, and xBrassicoraphanus, respectively. This suggests that both B. rapa (AA) and R. sativus (RR) genomes, particularly the rDNA arrays, co-exist in xBrassicoraphanus (AARR) genome. In meiosis I, nineteen bivalents were most frequent, and GISH analysis showed ten bivalents from the A genome. This study would provide a useful information for further genomic study of xBrassicoraphanus and its improvement as a new promising breeding variety.

Conventional staining and fluorescence in situ hybridization (FISH) karyotypes of the non-genetically modified (GM) parental rice line, 'Nakdong' (Oryza sativa L. japonica), and its four GM rice lines, LS28 (event LS30-32-20-1), Cry1Ac1 (event C7-1-9-1), and LS28 × Cry1Ac1 (events L/C1-1-3-1 and L/C1-3-1-1) were analyzed using 5S and 45S rDNAs as probes. Both parental and transgenic lines were diploids (2n=24) with one satellite chromosome pair. The lengths of the prometaphase chromosomes ranged from 1.50 to 6.30 μm. Four submetacentric and eight metacentric pairs comprised the karyotype of 'Nakdong' and its four GM lines. One pair of 5S rDNA signals was detected near the centromeric region of chromosome g in both the parental and transgenic lines. The 45S rDNA signals were detected on the secondary constrictions of the satellite chromosome pair in both the parental and transgenic lines. There was no significant difference in chromosome size, length, and composition between 'Nakdong' and its four GM lines. This research was conducted as a preliminary study for chromosomal detection of transgenes in GM rice lines and would be useful for their breeding programs.

New somatic chromosome numbers and karyotype analyses of 33 medicinal herbs (30 genera, 23 families) in Korea were investigated. The chromosome numbers of 4 taxa, Euryale ferox, Rodgersia podophylla, Cirsium japonicum var. ussurience, Eehinops setifer, showed results that are different from previous reports. Among 33 taxa, 23 taxa were reported for the first time, and karyotype analyses were newly conducted for 2 taxa (Tiarella polyphylla, Crepidiastrum denticulatum) in Korea. In addition, we observed for the first time the new chromosome numbers for 4 taxa distributed evenly over the world (Lindera erythrocarpa, Corylopsis glabrescens var. gotoana, Ardisia crenata, Callicarpa japonica var. luxurians).