Totally, 26 collections, 17 from Korea and 9 from China, were investigated for their sequences of 5S rDNA, especially the non-transcribed spacers (NTSs). Sequences of 5S rDNA were isolated by PCR using the primers, 5s-rRNA1 and 5s-rRNA2. Genomic DNA PCR produced single amplification of 300, 330, or 350 base pair fragments. Sequence analysis revealed that all inserts contained the part of 5S rDNA gene sequence and the full length of the NTS region. Three different sizes of the fragments were confirmed due to different size of NTS and their length were 300bp, 330bp and 350bp, respectively. Among 17 Korean foxtail millets tested, 14 collections showed single 300bp amplification. Longest fragment amplification, 350bp, was obtained only from the foxtail millet from China origin, even though 2 of them include 300bp fragment. CLUSTALW multiple alignments of 26 foxtail millets clearly revealed 4 areas with certain degree of sequence heterogeneity (region I, II, III, IV). Among 4 boxed areas, foxtail millet genotypes from China have distinct insertion especially in region III. Five of them have extra insertion of sequence and their additional sequences were either 45 or 48 base pair. Three Korean foxtail millets have 32 bp insertion. Other 8 Korean collections have short insert sequences (6 to 8 bp), 3 with 8 bp and 5 with 6 bp. In addition to insert, deletion sequences were also confirmed as major deletion was observed in region II of Chinese collection. The size of deletion was 7 bp long. According to phylogenic tree constructed using MEGA4 program, clear grouping was not revealed. To obtain more convincing results various collections from many countries should be obtained and analyzed to distinguish different germplasm from different origin.

Twenty two common millet (Panicum miliaceum L.) varieties collected from Korea, China and Russia were investigated for their phylogenetic relationship using 5S ribosomal DNA sequences with a hope to provide the basic information on their exact origin. Sequences of 5S rDNA were isolated by PCR. The primers, 5s-rRNA1 and 5s-rRNA2, were designed to isolate the complete NTS. Genomic DNA amplification produced two fragments with different length, 900 bp and 400 bp fragments, confirming the presence of two types of 5S rDNA repeats that differed from each other in the length of the NTS region. Amplified DNAs of 400 bp fragment were subcloned and used for further investigation. The obtained NTS sequences ranged from 200 to 300 bp and homology of sequences among plant materials was much higher than long repeat. CLUSTALW multiple aligment of 5S rDNA sequences from 22 different common millets revealed the clear difference by their origin. And critically different areas with insert or deletion were also confirmed. Those sequence difference seems to be used for discrimination of cultivars from different origin and use as molecular markers for origin identification. In phylogenic tree construction, the clear classification was shown where the genotypes from China and Russia is positioned together and stay away from domestic genotypes.