Molecular cytogenetic analysis and phylogenetic relationship of 5S and 45S ribosomal DNA in sinomartagon Lilium species by fluorescence in situ hybridization (FISH)

Abstract

This study was conducted to elucidate the evolution of chromosomal diversification in eight species of Lilium by fluorescence in situ hybridization (FISH) technique using ribosomal DNA probes for the 5S rDNA and 45S rDNA. A phylogenic tree was reconstructed based on the results of the sequence analysis of the non-transcribed spacer (NTS) and inter-transcribed spacer (ITS) regions. The FISH analysis showed Lilium lancifolium (2x) were composed of 3 pairs of 45S rDNA genes on short arms of chromosome # 1, 2, and 7, and 3 pairs on long arms of chromosome # 4, 6, and 11. L. callosum and L. concolor showed the same pattern with L. lancifolium. However, L. dauricum showed 3 pairs of signals on the short arm of chromosome # 1, 2, and 7, and a pair of 45S rDNA signals was detected on the long arms of chromosome # 6 by FISH. The sequence length of the ITS1 and ITS2 regions were 229 bp and 233 bp, respectively. The length of the NTS region, including 5S rDNA segment, was within the range of 474 to 678 bp. According to the phylogenic analysis, L. concolor, L. amabile and L. callosum were closely related, whereas L. lancifolium, diploid and triploid were distantly related.