三種蝴蝶蘭屬植物核糖體 RNA 基因的實質定位

Physical mapping of ribosomal RNA genes in three Phalaenopsis species

曾治中(Chih-Chung Tseng)

指導教授 ： 高燕玉

國立臺灣大學/生命科學院/分子與細胞生物學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.00447

摘要

屬於 Amboinenses 節之三種蝴蝶蘭原生種 P. fasciata、P. mariae 和 P. pallens 皆具 38 條染色體 (2n = 2x = 38)，且均為中型及小型染色體。利用雙標的螢光原位雜交將 rDNA 實質定位的結果，三種蝴蝶蘭皆具一對 5S 及 45S rDNA 基因座，且均位於小型染色體的末端。而屬於同節的 P. lueddemanniana、P. bastianii 及 P. pulchra 在染色體形態、DNA 含量以及 rDNA 基因座的數目皆與此三種蝴蝶蘭相似，顯示此六物種的親緣關係較接近；然而亦屬 Amboinenses 節之 P. amboinensis、P. venosa 和 P. violacea 則染色體較大，DNA 含量亦較高，且具 1~2 對 5S rDNA 基因座和 4~7 對 45S rDNA 基因座，與前六種蝴蝶蘭有顯著差異，故可將此九種蝴蝶蘭分為兩群，此與過去利用 5S rDNA 的 IGS 序列以及 45S rDNA 的 ITS 序列所建立之親緣關係樹的結果相吻合。rDNA 的實質定位提供蝴蝶蘭屬植物親緣關係探討的另一種證據。

關鍵字

蝴蝶蘭 ； 螢光原位雜交 ； rDNA ； 實質定位 ； 親緣關係

並列摘要

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.

並列關鍵字

Phalaenopsis ； fluorescence in situ hybridization ； rDNA ； Physical mapping ； phylogenetic relationship

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