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Yan Wang and Stanley J. Kays

The sweetpotato weevil (SPW) [Cylas formicarius elegantulus (Summers) (Coleoptera: Curculionidae)] is the single most devastating pest of the sweetpotato [Ipomoea batatas (L.) Lam.] worldwide. Attempts to develop host-plant resistance have been only moderately successful due in part to deficiencies in parent and progeny selection methods. Host-plant phytochemicals play critical roles in insect behavior, modulating a cross-section of key behavioral decisions. Thus, identification of the phytochemicals the female weevil uses in decision making could greatly facilitate development of host-plant resistance. The volatile chemistry of the sweetpotato was studied in relation to the host-finding behavior of the female weevil. Critical biologically active volatiles were determined via isolation (Tenax trapping), fractionation (gas chromatography-thermal conductivity detector), identification (gas chromatography and gas chromatography-mass spectroscopy), and bioassay (olfactometry). Differences in volatile chemistry among sweetpotato clones that may relate to differences in resistance or susceptibility to the female SPW were assessed. Volatile extracts from storage roots (site of oviposition) and aerial plant parts were attractive to female SPW, the former being substantially greater. In total, 33 compounds were identified from storage roots and aerial plant parts, including 23 terpenes. Three oxygenated monoterpenes (nerol, Z-citral, and methyl geranate), found in storage roots but not aerial plant parts, were identified as attractants. The sesquiterpene volatile fraction was repellent to female SPW with α-gurjunene, α-humulene, and ylangene active in the concentration range emanating from storage roots. The aerial plant parts emanated a higher composite concentration of sesquiterpenes than storage roots. Differences in the relative attraction among four sweetpotato cultivars to female SPW was inversely correlated with the composite concentration of headspace sesquiterpenes. Selection of clones with decreased volatile attractants and/or increased deterrents using an analytical means of quantification may significantly facilitate developing resistance to the SPW.

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John C. Beaulieu, Rebecca E. Stein-Chisholm, and Deborah L. Boykin

) according to Table 1 . OID were further subdivided into terpenes (ENE) and linalools (LOO). Table 1. Volatile compounds qualitatively recovered by headspace solid-phase microextraction using divinylbenzene carboxen polydimethylsiloxane fibers and gas

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Dansereau Blanche and Charest Pierre-Mathieu

chapters for the biosynthesis of volatile terpenes in the flowers of Arabidopsis thaliana as well as a genomic approach of floral scent in rose. A very interesting Section III deals with cellular and physiological aspects of floral scent synthesis and

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Jinhe Bai, Elizabeth Baldwin, Jack Hearn, Randy Driggers, and Ed Stover

). Nevertheless, the great abundance of terpenes, such as d -limonene and valencene, can indirectly affect the perception of other volatiles through their effects on volatility, which alters headspace partitioning ( Plotto et al., 2008 ). β-Myrcene was reported

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Xiaoxu Yang, Yinshan Guo, Junchi Zhu, Zaozhu Niu, Guangli Shi, Zhendong Liu, Kun Li, and Xiuwu Guo

, whereas Sun et al. (2014) reported that terpene accumulation was related to DXS transcript profiles in developing ‘Alexandria’ grapes ( V. vinifera ). In this study, UDV060 was shown to be related to monoterpenoid content and significantly associated

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Alan W. Meerow, Stewart T. Reed, Christopher Dunn, and Elena Schnell

component the terpenes ( E )-β-ocimene with detectable amounts of β-myrcene, ( Z )-β-ocimene, ( E )-epoxy-ocimene, an aliphatic ( Z )-3-hexenyl acetate, and a benzenoid benzyl benzoate ( Effmert et al., 2005 ). Minor components included alloocimene, ( Z )-3

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John C. Beaulieu, Maureen A. Tully, Rebecca E. Stein-Chisholm, and Javier M. Obando-Ulloa

in WPJ (68.5%) and almost identical (79.5%) in PPJ ( Table 3 ). Most of the limonene comes from peel oil and is introduced into the juice during mechanical extraction, and it is the most abundant terpene hydrocarbon in orange juice ( Perez-Cacho and

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Jennifer Han, Jan E. Murray, Qingyi Yu, Paul H. Moore, and Ray Ming

an inability to perceive GAs, but rather the result of a mutation independent of GA metabolism or perception. Three distinct classes of enzymes mediate the GA metabolism pathway. The terpene cyclase class is composed of two members, CPS and KS ( Aach

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Dong Sik Yang, Ki-Cheol Son, and Stanley J. Kays

ecological significance (e.g., pollinator attraction, defense) ( Aharoni et al., 2005 ). The specific terpene synthesized varied among species ( Owen and Peñuelas, 2005 ). Fifteen terpenoids were identified from S. wallisii of which four were monoterpenes

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Deron Caplan, Mike Dixon, and Youbin Zheng

carotenoids and the xanthophylls is upregulated in stressed plants to prevent cell damage ( Eskling et al., 1997 ; Munné-Bosch and Alegre, 2000 ). This may also be the case for other terpenes with antioxidant properties ( Delfine et al., 2005 ; Llusià and