Physical mapping of ribosomal RNA genes in three Phalaenopsis species
Date Issued
2009
Date
2009
Author(s)
Tseng, Chih-Chung
Abstract
Phalaenopsis fasciata, P. mariae and P. pallens classified to section Amboinenses had 38 chromosomes (2n = 2x = 38). Their chromosomes were small and medium in size. Physical mapping of rDNA using double-target fluorescence in situ hybridization (FISH) showed that all of these three species possessed one pair of 5S rDNA loci and one pair of 45S rDNA loci, and all of rDNA loci were located in the terminal site of small chromosomes. These results were similar to those of P. lueddemanniana, P. bastianii and P. pulchra. In addition, karyotype and DNA content among these six species were also much the same. It seemed that they were closely related. However, P. amboinensis, P. venosa and P. violacea also belonging to the same section had larger chromosomes and higher DNA content. They contained 1-2 pair of 5S rDNA loci and 4-7 pair of 45S rDNA loci. Therefore, these nine species could be divided into two groups. It was consistent with the previously constructed phylogenetic trees established by intergenic spacer (IGS) region of 5S rDNA and internal transcribed spacer (ITS) region of 45S rDNA. Physical mapping of rDNA provide another evidence for investigating phylogenetic relationships of Phalaenopsis species.
Subjects
Phalaenopsis
fluorescence in situ hybridization
Physical mapping
phylogenetic relationship
File(s)![Thumbnail Image]()
Loading...
Name
ntu-98-R95b43023-1.pdf
Size
23.32 KB
Format
Adobe PDF
Checksum
(MD5):31c4ebd24ff69819dff27be9e64b8942