ABSTRACT
Scent is one of the most important economic traits in Freesia hybrida. "Shiny Gold", a popular cultivar in South Korea, is widely cultivated for its scent. The relative scent intensity of "Shiny Gold" was approximately 16% higher in full-bloomed flower when compared to the yellow bud stage, while tissue-specifically, tepals showed higher intensity in electronic-nose (e-nose) analysis. E-nose analysis also showed that the scent intensity of "Shiny Gold" was higher and lower than "10C3-424" and "10C3-894", respectively, and was similar to "Yvonne". These results correlated to those of the olfactory tests. In total, 19 volatile compounds, including linalool, ß-ocimene, D-limonene, trans-ß-ionone were detected in gas chromatography-mass spectrometry analysis. Among these, linalool was the major volatile compound, accounting for 38.7% in "Shiny Gold". Linalool synthase and TPS gene expression corresponded to the scent intensity of the four cultivars, with the lowest expression in the "10C3-424". TPS 2, TPS 3, TPS 5, TPS 6 and TPS 8 were highly expressed in both bud and flower in "Shiny Gold", while the expression of TPS 4 was lower, relative to other TPS genes in both the flowering stages. These results may aid in enhancing scent composition in Freesia cultivars using marker-assisted selection.
ABSTRACT
The enantiomeric distribution and profile of volatiles in plants, which affect the biological and organoleptic properties, can be varied depending on extraction methods as well as their cultivars. The secondary volatile components of the needles of three conifer cultivars (Chamaecyparispisifera, Chamaecyparisobtusa, and Thujaorientalis) were compared. Furthermore, the effects of three different extraction methods--solid-phase microextraction (SPME), steam distillation (SD), and solvent extraction (SE)--on the composition and enantiomeric distribution of those volatiles were elucidated. Monoterpene hydrocarbons predominated in all samples, and the compositions of sesquiterpenes and diterpenes differed according to the cultivar. In particular, the yields of oxygenated monoterpenes and sesquiterpenes were greatest for SD, whereas those of sesquiterpenes and diterpenes were highest for SE. On the other hand, more monoterpenes with higher volatility could be obtained with SPME and SD than when using SE. In addition, the enantiomeric composition of nine chiral compounds found in three cultivars differed according to their chemotype. There were also some differences in the yielded oxygenated monoterpenes and sesquiterpene hydrocarbons, but not monoterpene hydrocarbons, according to the extraction method. These results demonstrate that the extraction methods used as well as the cultivars influence the measured volatile profiles and enantiomeric distribution of coniferous needle extracts.
