title: Seasonal variation of monoterpene emission from Malus domestica and Prunus avium.
abstract: Emission rates of monoterpenes released by apple (Malus domestica Borkh) and cherry (Prunus avium L.) were estimated at different phenological stages. These measurements employed a dynamic flow-through Teflon chamber, sample collection onto cartridges filled with graphitized carbon and thermal desorption gas chromatography-mass spectrometry (GC-MS) for identification and quantification of the emitted volatiles. At full bloom the release of monoterpene hydrocarbons from cherry flowers was 1213 ng g(-1) dry weight (DW) h(-1), exceeding by approximately three-fold the emission rate of apple flowers (366 ng g(-1) DW h(-1)). Observed seasonal variations in biogenic volatile organic compound (VOC) emissions ranged over several order of magnitudes. At fruit-set and ripening stages, in fact, the hydrocarbon emission dramatically decreased reaching the lowest values at harvest time when leaves were fully mature (3-9 ng g(-1) DW h(-1)). Wide diversity in the composition of compounds from the species studied was also recorded. At blooming, linalool contributed significantly to the monoterpene emission from apple (94% of the emitted carbon) while alpha-pinene and camphene represented on average more than 60% of the total emitted volatiles from cherry flowers. Among the monoterpenes identified in flowers, alpha-pinene, camphene and limonene were also found in the foliage emission of both species. Fruit trees are relevant monoterpene emitters only at blooming and thus for a short period of the vegetative cycle. When leaves are fully developed, the carbon loss due to monoterpene emissions related to the photosynthetically carbon gain is negligible.
authors.affiliation: Istituto di Ecofisiologia delle Piante Arboree da Frutto, CNR, Via Gobetti 101, 40129 Bologna, Italy. rapparini@istea.bo.cnr.it
authors.forename: F
authors.initials: F
authors.lastname: Rapparini
authors.forename: R
authors.initials: R
authors.lastname: Baraldi
authors.forename: O
authors.initials: O
authors.lastname: Facini
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry; D019685:Rosales / Q000378:metabolism*; D012621:Seasons; D013729:Terpenes / Q000378:metabolism*; D014835:Volatilization
chemical_list: D013729:Terpenes