|Giacomuzzi, Valentino - Free University Of Bozen-Bolzano|
|Cappellin, Luca - Harvard University|
|Nones, Stefano - Fondazione Edmund Mach|
|Khomenko, Iuliia - Fondazione Edmund Mach|
|Biasiolo, Franco - Free University Of Bozen-Bolzano|
|Angeli, Sergio - Free University Of Bozen-Bolzano|
Submitted to: Phytochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/4/2017
Publication Date: 6/1/2017
Citation: Giacomuzzi, V., Cappellin, L., Nones, S., Khomenko, I., Knight, A.L., Biasiolo, F., Angeli, S. 2017. Diel rhythms in the volatile emission of apple and grape foliage. Phytochemistry. 138:104-115.
Interpretive Summary: Characterizing the compounds released by plants can help in the discovery of new insect pest attractants that can improve management for growers. Researchers at the USDA, ARS, Yakima Agricultural Research Laboratory, Wapato, WA in collaboration with researchers at Free University of Bozen, Bolzano, Italy characterized the volatiles released by intact apple and grape plants during both the day and night periods. These data were useful to guide subsequent field trials with a subset of compounds to determine attraction for both moth sexes of Pandemis heparana, an important moth pest of orchards in Europe that is now introduced into North America. Information from this research supports the continued effort to develop even more effective lures that can be used in trap-based monitoring program for important moth pests in tree fruits.
Technical Abstract: This study investigated the emission of volatile organic compounds (VOCs) from intact apple (Malus x domestica Borkh., cv. Golden Delicious) and grape (Vitis vinifera L., cv. Pinot Noir) foliage. Volatiles were monitored continuously for 48 hours by proton transfer reaction - time of flight - mass spectrometry (PTR-ToF-MS). In addition, volatiles were collected by closed-loop-stripping-analysis (CLSA) and characterized by gas chromatography-mass spectrometry (GC-MS) after 1 hour and again 24 and 48 hours later. Fourteen and nine volatiles were characterized by GC-MS in apple and grape, respectively. The majority of these were terpenes, followed by green leaf volatiles, and aromatic compounds. The PTR-ToF-MS identified 10 additional compounds and established their circadian pattern of emissions. The most abundant volatiles displaying a circadian rhythm included methanol and dimethyl sulfide in both plants, acetone in grape, and mono-, homo- and sesquiterpenes in apple. The majority of volatiles were released from both plants during the photophase, whereas methanol, CO2, methyl-butenol and benzeneacetaldehyde were significantly more abundant during the scotophase. Acetaldehyde, ethanol, and some green leaf volatiles showed distinct emission bursts in both plants following the daily initiation of scotophase. These new results obtained with a combined analytical approach broadens our understanding of the temporal patterns of constitutive volatile release from two important horticultural crops. In particular, circadian emission of sulfur and nitrogen-containing volatiles are reported here for the first time in these crops.