벼멸구 수컷 정소에서 염색체의 변이정도를 생태형 별로 관찰하였다. 세포 분열 지수는 생태형 3에서 가장 높았고 그 다음으로 생태형 1, 생태형 2이었다. Agmatoploidy, aneuploidy, 성염색체의 loose pairings과 같은 염색체의 구조적 변화는 생태형 1, 생태형 2, 생태형 3순으로 높았다. 감수분열 제1분열기 중기는 성염색체가 상염색체로부터 현격하게 분리되어 있는 세포의 수는 생태형 2에서 가장 높았다.

The 5S rRNA gene is considered as valuable resource for chromosome landmarks and evolutionary studies. In this study, the tandem repeat unit of 5S rRNA gene containing the coding sequence and non‐transcribed spacer (NTS) region was amplified by PCR, cloned, and sequenced from Allium wakegi (2n=XY=16) and the two ancestors, A. cepa and A. fistulosum. Although there were intraspecific variations among the clones of each species, we could construct each consensus sequences for A. cepa and A. fistulosum and two consensus sequences for A. wakegi. The sequence of the 120 bp coding region was completely homologous among the consensus sequences from the Allium species examined. However, the sequence in the NTS region was significantly variable and informative in genome analysis. The variations were found to be clustered between the positions 230 and 269, and also distributed broadly as single nucleotide. A. wakegi could be divided into two classes by the 5S rRNA sequences (AWAK‐1 and AWAK‐2). AWAK‐1 showed high homology to the genome of A. cepa and AWAK‐2 to that of A. fistulosum. Fluorescence in situ hybridization technique was applied to analyze the distribution of 5S gene loci. In A. wakegi, 5S rRNA sequences were detected in two different chromosomes, each one showing the pattern identical to the chromosome donated from each genome of both ancestors.

Analyses of now karyotypes using different maize (Zea mays L.) inbred lines have been performed. The accumulation and isolation of high quality and quantity metaphase chromosomes from root tips can be achieved from many kinds of maize lines. The chromosome suspensions were prepared by a simple slicing method from synchronized maize root tips and analyzed with a now cytometry. The variations of experimental now karyotypes were detected among inbred lines in terms of the positions and/or the numbers of chromosome peaks. The 2C DNA amount among 8 inbred lines ranged from 5.09 to 5.52 pg. The variability of DNA content in maize chromosome 1 was 9.1 % ranging from 0.685 to 0.747 pg. The selection of appropriate maize lines is critical for sorting specific single chromosome types. At least five different chromosome types can be discriminated and sorted from five maize lines.