Abstract

Vanda ‘Tan Chay Yan’, a beautiful golden-orange orchid with mild fragrance, is valuable in the floral industry. In this study, the volatile compounds from the flowers were profiled and a transcriptome library was created to search for fragrance-related transcripts. Volatiles from the tepals were captured using a SPME device with PDMS-coated fibre for GC-MS analysis. A transcriptome library was constructed and sequenced using the Illumina MiSeq Desktop Sequencer, de novo assembled using CLC Genomic Workbench version 6.0. BLASTx analysis, functional annotations and gene mapping of the annotated genes to the KEGG database were carried out using the Blast2go Pro software. Twelve compounds were identified in the volatiles including monoterpenes (93.19%), sesquiterpenes (4.32%) and traces of other compounds (2.49%) whereby cis-β-ocimene topped the list as the major constituent (88.41%). De novo assembly of the transcriptome generated a total of 34,027 sequences from which 20 fragrance-related transcripts in the terpenoid and benzenoid/phenylpropanoid biosynthetic pathways were identified. Combined information garnered from the volatiles and fragrance-related transcripts highlights the basic information on the fragrance constituents and biosynthetic pathways of this orchid which are useful for orchid breeders in selection of parents for new hybrids with fragrance as their value-added characteristic for the floriculture industry.

摘要

Vanda 'Tan Chay Yan' 是一种美丽的金橙色兰花，香气温和，在花卉产业中极具价值。在这项研究中，对花朵中的挥发性化合物进行了分析，并创建了一个转录组库来搜索与香味相关的转录本。使用带有 PDMS 涂层纤维的固相微萃取装置捕获花被中的挥发物，用于 GC-MS 分析。使用 Illumina MiSeq Desktop Sequencer从头构建转录组文库并对其进行测序使用 CLC Genomic Workbench 6.0 版组装。使用 Blast2go Pro 软件进行 BLASTx 分析、功能注释和注释基因到 KEGG 数据库的基因定位。在挥发物中鉴定出12种化合物，包括单萜（93.19%）、倍半萜（4.32%）和微量其他化合物（2.49%），其中顺式-β-罗勒烯位居榜首（88.41%）。从头转录组的组装产生了总共 34,027 个序列，从中鉴定了 20 个萜类和苯类/苯丙烷类生物合成途径中与香味相关的转录物。从挥发物和香味相关的转录本中获得的综合信息突出了这种兰花的香味成分和生物合成途径的基本信息，这些信息有助于兰花育种者选择具有香味作为花卉产业增值特征的新杂交种的亲本.