Comparative Analysis of Flower Volatiles from Nine Citrus at Three Blooming Stages

Abstract

Volatiles from flowers at three blooming stages of nine citrus cultivars were analyzed by headspace-solid phase microextraction (HS-SPME)-GC-MS. Up to 110 volatiles were detected, with 42 tentatively identified from citrus flowers for the first time. Highest amounts of volatiles were present in fully opened flowers of most citrus, except for pomelos. All cultivars were characterized by a high percentage of either oxygenated monoterpenes or monoterpene hydrocarbons, and the presence of a high percentage of nitrogen containing compounds was also observed. Flower volatiles varied qualitatively and quantitatively among citrus types during blooming. Limonene was the most abundant flower volatile only in citrons; α-citral and β-citral ranked 2nd and 3rd only for Bergamot, and unopened flowers of Ponkan had a higher amount of linalool and β-pinene while much lower amount of γ-terpinene and p-cymene than Satsuma. Taking the average of all cultivars, linalool and limonene were the top two volatiles for all blooming stages; β-pinene ranked 3rd in unopened flowers, while indole ranked 3rd for half opened and fully opened flower volatiles. As flowers bloomed, methyl anthranilate increased while 2-hexenal and p-cymene decreased. In some cases, a volatile could be high in both unopened and fully opened flowers but low in half opened ones. Through multivariate analysis, the nine citrus cultivars were clustered into three groups, consistent with the three true citrus types. Furthermore, an influence of blooming stages on clustering was observed, especially with hybrids Satsuma and Huyou. Altogether, it was suggested that flower volatiles can be suitable markers for revealing the genetic relationships between citrus cultivars but the same blooming stage needs to be strictly controlled.

Dynamic trajectories of volatile and non‐volatile specialised metabolites in ‘overnight’ fragrant flowers of Murraya paniculata

“…The ubiquity of terpenoids among the floral content was similar to the closely related Citrus flowers, but also divergent due to the dominance of sesquiterpenes rather than monoterpenes reported in Citrus species (Azam et al . ). Functionally, accumulation of terpenoid ESM without subsequent emission served as a reserve of defensive phytochemicals for the floral tissue, as scent emission attracted non‐pollinating herbivores as well as pollinators (Kessler & Baldwin ; Ghirardo et al .…”

Repellent Effects of Methyl Anthranilate on Western Corn Rootworm Larvae (Coleoptera: Chrysomelidae) in Soil Bioassays

“…MA is an appealing compound to consider for use against an agricultural pest such as the western corn rootworm because it is nontoxic (GRAS-list) and has been shown to be safe for humans as well as other vertebrates and invertebrates (TGSC 2015). Natural sources of MA include fruits (Genovese et al 2004, Sun et al 2011, Azam et al 2013, Chambers et al 2013) and flowers (Lee et al 2008, Lin et al 2013, and it is widely used in the perfume industry and as a food additive because of its strong grape-like odor (TGSC 2015).…”

The Sensory Quality Improvement of Citrus Wine through Co-Fermentations with Selected Non-Saccharomyces Yeast Strains and Saccharomyces cerevisiae

“…Ponkan (Citrus reticulata Blanco cv. Ponkan) is widely cultivated in Asian countries for its high quality [1]. Ponkan has a thin skin, and the quality of the fruit during storage at room temperature is highly prone to deterioration and decay over time.…”