Horticultural Science and Technology ISSN:1226-8763(Print) 2465-8588(Online) 원예과학기술지

Floral volatiles play a key role in attracting pollinators, and floral scent is an important trait for many floricultural crops, including orchids. Maxillaria tenuifolia belongs to the Orchidaceae family and has highly fragrant flowers. Due to the importance of plant biology, we needed to isolate the floral volatiles and corresponding genes in this plant. In this study, we investigated the floral volatile compounds and gene expression of M. tenuifolia at various flower developmental stages and in different floral organs using headspace–solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME-GC-MS) and quantitative real time PCR (qRT-PCR). The main compounds of M. tenuifolia were sesquiterpene, known as the scent of coconut, and the compounds β-caryophyllene, α-copaene, and δ-decalacton. The total amounts of volatile compounds in petal, sepal, lip, and column was 94.0%, 93.0%, 72.7%, and 90.0%, respectively. The compounds α-copaene, β- caryophyllene, and caryophylladienol II were identified in all parts. The total volatile compound amount at the bud stage (I) was 29.1%, at the initial flowering stage (II) was 81.0%, at the full flowering stage (III) was 93.7%, at the loss of pedicel color stage (IV) was 85.6%, and at the wilting flower stage (V) was 69.8%. Except for the bud stage (I), α-copaene and β-caryophyllene were identified in all stages. In the qRT-PCR analysis, most of the terpenoid genes were highly expressed at the full flowering stage in the sepal and petal. According to these results, we concluded that sesquiterpene is the major source for the floral scent profile in this plant. This study establishes a baseline for product development and provides information about using aromatics to promote orchid consumerism by identifying and analyzing volatile compounds and gene expression.