Emission of Volatile Chemicals from Flowering Dogwood (Cornus florida L.) Flowers

Abstract

Reproduction of flowering dogwood trees occurs via obligate out-crossing, and U.S. native bees have been suggested to be primary pollinators of this ecologically and economically important deciduous tree. Whether floral volatiles play a role in reproduction of the dogwood remains unclear. Objectives of this study were to identify principal volatile chemicals emitted from dogwood flowers and to assess a temporal volatile emission profile and volatile consistency across four cultivars. Inflorescences with intact bracts and 5 cm flower pedicel were removed from dogwood trees and subjected to headspace volatile collection. Six principal volatile compounds were detected from the flowers of the cultivar 'World's Fair' with 3-formylpyridine as the most abundant constituent. Subsequent headspace analyses performed using inflorescences without bracts or floral pedicels alone indicated that 3-formylpyridine, E-beta-ocimene, S-linalool, and ketoisophorone were mainly emitted from inflorescences. Experiments were also conducted to determine whether volatile emissions differed across time and between different cultivars of flowering dogwood. When volatile emission was analyzed for 48 h using 12 h light/dark cycles, the emission of several volatile compounds displayed diurnal patterns. Finally, whereas florets in inflorescences of four different dogwood cultivars emitted similar levels of the six principal floral volatile chemicals, 'Cherokee Brave' flowers alone yielded 4-methoxybenzaldehyde and germacrene-D. The implications of the findings of this study to dogwood breeding programs are discussed.

Genetic variation and metabolic pathway intricacy govern the active compound content and quality of the Chinese medicinal plant Lonicera japonica thunb

“…In addition, we observed the decreased content of isopropyl laurate and the increased contents of linalool and germacrene D in the flowering process (Figure 5B). Isopropyl laurate, linalool, and germacrene D are all known major volatile chemicals released in full-bloomed flowers [43]. …”

Regulation of Floral Terpenoid Emission and Biosynthesis in Sweet Basil (Ocimum basilicum)

“…Therefore, the emissions vary qualitatively and quantitatively during anthesis. The diurnal rhythmic patterns of floral volatile release is either directly regulated by light (Jiang and others 2011b) or by circadian clock (Zhuang and others 2008; Jiang and others 2011a; Kong and others 2012), but it is unknown whether O. basilicum exhibits diurnal variations in volatile release and if it does, what factors are responsible for such diurnal variations. Understanding the diurnal variation patterns and their controlling mechanisms is of importance in explaining the biological role of floral volatile emission in O. basilicum .…”

Floral Scent in Wisteria: Chemical Composition, Emission Pattern, and Regulation

“…VOLATILE COLLECTION AND ANALYSIS. Volatiles emitted from flowers were collected in an open headspace sampling system (Analytical Research System, Gainesville, FL) under the controlled environment [22°C (day/night), 100 mEÁm -2 Ás -1 illumination] as previously reported (Zhuang et al, 2008). A single raceme in a single flask with %150 mL of distilled water was placed in a glass chamber (10 cm diameter and 30 cm tall) covered with a removable O-ring snap lid.…”