Genome Organization and Relationships of Phalaenopsis Orchids Inferred from Genomic in Situ Hybridization

以基因組原位雜交探討蝴蝶蘭屬植物的基因組組成與親緣關係

林志忠(Chih-Chung Lin) ； 陳燿煌(Yao-Huang Chen) ； 陳文輝(Wen-Huei Chen) ； 陳其昌(Chi-Chang Chen) ； 高燕玉(Yen-Yu Kao)

《Botanical Bulletin of Academia Sinica》 46卷4期 (2005/10) Pp. 339-345

https://doi.org/10.7016/BBAS.200510.0339

摘要

所有蝴蝶蘭屬植物皆含38條染色體，但是它們基因組大小卻有很大的差異。本研究將基因組相似或不相似的蝴蝶蘭原生種交配後，所得到的七種種間雜交種，以基因組原位雜交探討它們的基因組組成與親緣關係。實驗結果，兩親本皆具小基因組的雜交種P. aphrodite × P. sanderiana，由雜交訊號的強度與分佈無法區分兩親本的染色體；而兩親本皆具大基因組的雜交種P. mannii × P. violacea結果亦同，顯示這類雜交種的兩親本含有相似的基因組。但若雜交種中一親本具大的基因組，而另一親本具小的基因組，例如P. amboinensis × P. stuartiana，則不論是否添加阻隔DNA，利用基因組原位雜交均很容易區分兩親本的染色體。檢視染色體上的雜交訊號，顯示具大基因組的蝴蝶蘭原生種無論在種類與量上均含有較多的重複性序列，然而具小基因組的原生種亦含有其本身特殊的序列。總之，由基因組原位雜交所獲得的基因組間的親緣關係與其他研究者利用傳統基因組分析的結果相吻合。此研究顯示基因組原位雜交是一種探討植物基因組組成與親緣關係很有用的工具，尤其是對分析減數分裂行為技術上有困難的植物。

關鍵字

基因組原位雜交 ； 基因組組成 ； 基因組親緣關係 ； 蝴蝶蘭屬

並列摘要

All Phalaenopsis species have the same chromosome number (2n=2χ=38), but the sizes of their genomes vary markedly. In this study, we investigated genome organization and relationships of Phalaenopsis species by genomic in situ hybridization (GISH) of seven interspecific hybrids derived from crosses between species with similar or dissimilar sizes of genomes. In the hybrid P. aphrodite × P. sanderiana, in which both parents possess small genomes, the two parental chromosome sets could not be distinguished by the strength and distribution of hybridization signals. Similar results were obtained from the hybrid P. mannii × P. violacea, in which both parents have large genomes. These results suggest that the two parents of these hybrids have similar genomes. In hybrids in which one parent possesses a large and the other parent a small genome, such as P amboinensis × P. stuartiana, the two parental chromosome sets could readily be distinguished by GISH with or without the application of blocking DNA. Examination of hybridization signals on chromosomes revealed that species with large genomes have much more repetitive sequences, both in type and amount; however, species with small genomes do have their own specific sequences. In general, genome relationships obtained from GISH are in agreement with those from traditional genome analysis of other investigators. This study demonstrates that GISH is a useful tool for investigating genome organization and relationships of plant species, especially when analysis of meiotic behavior is technically difficult.

並列關鍵字

Genomic in situ hybridization ； Genome organization ； Genome relationship ； Phalaenopsis