博士 / 國立成功大學 / 生命科學系 / 106 / Phalaenopsis orchid is one of the top ornamentals in global horticulture market. P. aphrodite (2n= 2x= 38) is an important parent in Phalaenopsis breeding and it is the specie of choice for whole genome sequencing owing to its relatively smaller genome size (2.8 pg/ 2C) in this genus. However, none of molecular cytogenetic map which integrates the genetic and genomic datasets to the chromosomal locations and structures was available in orchids. Fluorescence in situ hybridization (FISH) has been a reliable technique for mapping DNA markers on chromosomes. In this study, a modified drop method for pachytene chromosome preparation was first developed. Phalaenopsis meiotic pachytene chromosomes revealed up to 20 times higher resolution than their mitotic metaphase counterparts and the first pachytene-based karyotype of P. aphrodite was established. Second, the linkage group DNA markers were FISH mapped. Thus, the 22 Phalaenopsis linkage groups were successfully integrated with the 19 chromosomes of P. aphrodite. All the orders of the FISH signals were consistent to those revealed in the genome assembly and genetic linkage map, demonstrating the high quality of the physical and genetic maps. Furthermore, the anchored DNA markers were applied as chromosome-specific markers to facilitate chromosome identification and assisted to assign the unmapped scaffolds to the molecular cytogenetic map. Last, on the basis of chromosomal localizations, sequence divergences and transcriptomic expression profiles of the five CHS (chalcone synthase) genes, the expansion of the gene family occurred through segmental duplications followed by tandem duplications was proposed. The accomplishment of this study sets a solid foundation by integrating Phalaenopsis genetic, genomic and chromosomal datasets and opens the possibility for chromosome-scale comparative genomics in orchids.
| Identifer | oai:union.ndltd.org:TW/106NCKU5105024 |
| Date | January 2018 |
| Creators | Yi-TzuKuo, 郭怡孜 |
| Contributors | Song-Bin Chang, 張松彬 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | en_US |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 94 |
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