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  • 1.
    Danielsson, Marie
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Kännaste, Astrid
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Lindström, Anders
    School of Industrial Technology and Management, Dalarna University.
    Hellqvist, Claes
    Department of Ecology, Swedish University of Agricultural Sciences.
    Stattin, Eva
    School of Industrial Technology and Management, Dalarna University.
    Långström, Bo
    Department of Ecology, Swedish University of Agricultural Sciences.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Mini-seedlings of Picea abies are less attacked by Hylobius abietis than conventional ones: Is plant chemistry the explanation?2008Ingår i: Scandinavian Journal of Forest Research, ISSN 0282-7581, E-ISSN 1651-1891, Vol. 23, nr 4, s. 299-306Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The pine weevil, Hylobius abietis (L.), is a major pest in conifer reforestation areas in the Palaearctic region. Size and chemistry of the seedlings may explain the damage rates in plantations. The performance of 10-week containerized seedlings (mini-seedlings) was compared with 1-year-old conventional seedlings of Norway spruce, Picea abies (L.), in a field experiment in central Sweden. After 2 years the weevil damage was lower for the mini-seedlings than for the conventional seedlings (3.5 vs 55%). After 3 years, the overall survival was 82 and 75%, respectively. Weevil damage was the main cause of mortality for conventional seedlings, whereas mini-seedlings mainly died from drought. Volatiles of the two seedling types were compared by solid-phase microextraction-gas chromatography -mass spectrometry (SPME-GC-MS). Unwounded mini-seedlings and conventional seedlings differed in their compositions of monoterpenes and sesquiterpenes. Miniseedlings mainly emitted limonene, known to be repellent to the pine weevil. When wounded, green leaf volatiles were released by mini-seedlings while the pine weevil attractant alpha-pinene was released by conventional seedlings. Volatiles may partly explain the mini-seedlings' resistance against weevil attack. Further studies are needed to clarify how long this miniseedling effect remains.

  • 2.
    Kännaste, Astrid
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Volatiles of Conifer Seedlings: Compositions and Resistance Markers2008Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Pine weevils cause major damage to newly planted conifer seedlings in reforestation areas. However, recent findings indicate that small (“mini”) seedlings, planted at the age of 7-10 weeks, are gnawed less by pine weevils than the larger, conventionally planted seedlings. Thus, it has been proposed that planting young conifer seedlings in clear-cut areas may reduce the damage caused by pine weevils. In attempts to determine why mini seedlings appear to be less damaged by pine weevils than “conventional” seedlings, the volatiles released by Norway spruce and Scots pine mini seedlings were investigated, since such chemicals are of great importance in herbivore-plant communication, inter alia acting as repellents, attractants or antifeedants.

    Volatiles from the seedlings were collected, separated and identified by solid phase microextraction (SPME) followed by gas chromatography-mass spectrometry.

    The results show that there are high levels of chemodiversity among both spruce and pine seedlings. Between-tissue and age-related variations in their emissions were also found.

    Norway spruce clones infested by mites were also examined to assess genotype- and pest-specific stress reactions of Norway spruce. Finally, the effects of certain spruce defense compounds on the behavior of the large pine weevil Hylobius abietis were examined.

  • 3.
    Kännaste, Astrid
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Correlations between terpenes emitted by mini-plants of Norway spruce and Scots pineManuskript (Övrigt vetenskapligt)
  • 4.
    Kännaste, Astrid
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Nordenhem, Henrik
    Department of Ecology, Swedish University of Agricultural Sciences.
    Nordlander, Göran
    Department of Ecology, Swedish University of Agricultural Sciences.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Volatiles from a Mite-Infested Spruce Clone and Their Effects on Pine Weevil Behavior2009Ingår i: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 35, nr 10, s. 1262-1271Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Induced responses by Norway spruce (Picea abies) seedlings to feeding damage by two mite species were studied by analyzing the volatiles emitted during infestation. Four specimens of a Norway spruce (Picea abies L.) clone were infested with mites of Nalepella sp., another four with Oligonychus ununguis, and four were kept mite-free as controls. After a year of infestation, spruce volatiles were collected, analyzed, and identified using SPME-GC-MS. In addition, enantiomers of chiral limonene and linalool were separated by two-dimensional GC. Methyl salicylate (MeSA), (-)-linalool, (E)-beta-farnesene, and (E,E)-alpha-farnesene were the main volatiles induced by both species of mites, albeit in different proportions. The ability of the main compounds emitted by the mite-infested spruces to attract or repel the pine weevil, Hylobius abietis (L.), was tested. (E)-beta-farnesene was found to be attractive in the absence of spruce odor, whereas methyl salicylate had a deterrent effect in combination with attractive spruce odor. The other tested compounds had no significant effects on the behavior of the weevils.

  • 5.
    Kännaste, Astrid
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Vongvanich, Namphung
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Infestation by a Nalepella species induces emissions of alpha- and beta-farnesenes, (-)- linalool and aromatic compounds in Norway spruce clones of different susceptibility to the large pine weevil2008Ingår i: Arthropod-Plant Interactions, ISSN 1872-8855, Vol. 2, nr 1, s. 31-41Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The emissions of spruce grafts (Picea abies), caused by infestation of an acarid species of the genus Nalepella were investigated. Volatiles of three clones, both healthy and infested, with different susceptibility to the large pine weevil Hylobius abietis were collected by solid phase micro extraction (SPME) and analyzed by gas chromatograph coupled to mass-spectrometry (GC-MS). In addition, enantiomers of the main chiral compounds were separated by a two dimensional-gas chromatograph (2D-GC). In the characteristic flower-like fragrances emitted by the infested grafts large amounts of E-beta-farnesene, E, E-alpha-farnesene, (-)-linalool, methyl salicylate and minute amounts of benzyl alcohol, E-anethole, methyl benzoate, neral and geranial were found. All together, these compounds could explain the characteristic scent emitted by the infested seedlings. Large differences in the emissions of E-beta-farnesene, E, E-alpha-farnesene and methyl salicylate were found between but not within the clones.

  • 6.
    Kännaste, Astrid
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Zhao, Tao
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Lindström, A.
    Stattin, E.
    Långström, B.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Odors of Norway spruce (Picea abies L.) seedlings: Differences due to age and chemotype2013Ingår i: Trees, ISSN 0931-1890, E-ISSN 1432-2285, Vol. 27, nr 1, s. 149-159Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Small conifer seedlings (mini-seedlings) are less damaged by the large pine weevil Hylobius abietis (L.) (Coleoptera: Curculionidae) compared to conventional seedlings. Chemical difference between the seedling types is one possible explanation for this phenomenon. In the present paper, the emissions of volatile organic compounds (VOC) of 7- to 43-week-old Norway spruce [Picea abies (L.) Karst.] seedlings were analyzed. Collection and identification of the volatiles was made by solid phase micro-extraction and gas chromatography mass spectrometry (SPME-GC-MS). The enantiomers of α-pinene and limonene were separated in a two-dimensional GC (2D-GC). Most of the seedlings represented either a limonene- or a bornyl acetate-chemotype. Only minor changes in the volatile composition of the two types of seedlings were found during the first year. Age-related changes, however, were found in the volatiles released by wounded phloem where green leaf volatiles (GLVs) and borneol were the dominated VOC for young seedling. The attractive compound for the pine weevil, α-pinene, was first detected in the phloem emissions of 18- to 22-week-old seedlings. Different storage conditions of the seedlings during the winter/early spring-phase influenced the volatile composition in the phloem. High amount of GLVs was characteristic for the 43-week-old seedlings stored in naturally changing outdoor temperature, but not present in the seedlings winter-stored at a constant temperature of -4 °C. The possible role of these observed differences in odor emissions between seedlings of different age and physiological status for the feeding preferences of the large pine weevil is discussed.

  • 7.
    Kännaste, Astrid
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Zhao, Tao
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Lindström, Anders
    Dalarna University, School of Industrial Technology and Management.
    Stattin, Eva
    Dalarna University, School of Industrial Technology and Management.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Långström, Bo
    Swedish University of Agricultural Sciences, Department of Entomology.
    Odors of Norway spruce (Picea abies) seedlings: differences due to age and chemotype and their relevance for weevil resistanceManuskript (Övrigt vetenskapligt)
  • 8.
    Kännaste, Astrid
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Zhao, Tao
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Lindström, Anders
    Dalarna University, School of Industrial Technology and Management.
    Stattin, Eva
    Dalarna University, School of Industrial Technology and Management.
    Långström, Bo
    Swedish University of Agricultural Sciences, Department of Entomology.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Volatile emissions from pine seedlings: age-related changes and chemotypesManuskript (Övrigt vetenskapligt)
  • 9.
    Lindh, Jenny
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Kännaste, Astrid
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Knols, B. G. J.
    Faye, Ingrid
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Oviposition Responses of Anopheles gambiae s.s. (Diptera: Culicidae) and Identification of Volatiles from Bacteria-Containing Solutions2008Ingår i: Journal of medical entomology, ISSN 0022-2585, E-ISSN 1938-2928, Vol. 45, nr 6, s. 1039-1049Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, a dual-choice oviposition bioassay was used to screen responses of gravid An. gambiae toward 17 bacterial species, previously isolated from Anopheles gambiae s.l. (Diptera: Culicidae) midguts or oviposition sites. The 10 isolates from oviposition sites have been identified by phylogenetic analyses of their 16S rRNA genes. Eight of the 10 isolates were gram-positive, out of which six belonged to the Bacilli class. Solid phase microextraction and gas chromatography coupled to mass spectrometry (GC-MS) were used to identify the volatiles emitted From the bacterial isolates, Aromatic and aliphatic alcohols, aliphatic ketones, alkylpyrazines, dimethyl oligosulfides, and indole were among the chemical compounds identified from the headspace above bacteria-containing saline. The mosquitoes laid significantly more eggs in six of the bacteria-containing solutions compared with the sterile solution. These six bacteria did not emit any compounds in common that could explain the positive oviposition response. Instead. the bacteria were grouped according to principal component analysis (PCA) based on the relative amouts of volatile emitted. The PCA-plots facilitated the identification of 13 putative oviposition attractants for An. gambiae mosquitoes.

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