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- Björklund, Niklas, et al.
(författare)
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Exploiting jasmonate-induced responses for field protection of conifer seedlings against a major forest pest, Hylobius abietis
- 2014
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 313, s. 212-223
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Tidskriftsartikel (refereegranskat)abstract
- Herbivore damage commonly initiates an increased synthesis of chemical defensive compounds in attacked plants. Such induced defences are a vital part of plant defence systems, but when herbivore pressure is high, as frequently occurs in man-made ecosystems such as agricultural and forest plantations, plants may suffer considerable damage before adequate induced defences build up. To prepare the plants for such conditions their induced defence may be artificially triggered by the exogenous application of different phytohormones involved in damage signalling. This method is already employed in agriculture but within forestry systems it has so far been restricted to promising laboratory results. The pine weevil, Hylobius abietis, causes damage by feeding on the bark of young conifer plants and it is one of the main threats to successful regeneration in the Palaearctic region. Here we present results from a large scale field experiment where we triggered the induced defences of conifer seedlings using exogenous application of the chemical elicitor methyl jasmonate. To enhance the generality of the results different species were planted under extremely different environmental conditions; Maritime pine and Monterrey pine in Spain, and Scots pine and Norway spruce in Sweden. Weevil damage, chemical defences, and seedling growth were studied during the two growing periods following planting. In general, treated plants showed increased quantitative defences, and were less attacked, less wounded, less girdled and showed lower mortality rates than their untreated counterparts. Effects were mostly dose dependent, although some interactive effects with tree species were observed. The treatment initially caused a growth reduction but it was later compensated by the benefit, in terms of growth, of being less damaged. The measures that are currently taken to protect forest plantations against this harmful pest all around Europe have enormous economic costs and cause important environmental hazards. Elicitation of inducible defences in seedlings in the nursery appears to be an attractive alternative to these measures. To our knowledge, this is the first field study that explores the applicability of chemical elicitors of induced defences as a way to protect forest plantations against biotic threats. (C) 2013 Elsevier B.V. All rights reserved.
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- Björklund, Niklas, et al.
(författare)
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Snytbaggen : åtgärder för lyckade planteringar
- 2014
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Annan publikation (populärvet., debatt m.m.)abstract
- Barrträdsplantor som planterats efter avverkning blir ofta dödade av snytbaggens gnag. Men genom olika åtgärder kan skadorna minskas till en acceptabel nivå. Vilka metoder du bör välja beror bland annat på var i landet hygget ligger. Denna broschyr syftar till att förklara vilken effekt på plantskadorna olika åtgärder ger och hur de kan kombineras i olika delar av Sverige.
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- Danielsson, Marie, et al.
(författare)
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Mini-seedlings of Picea abies are less attacked by Hylobius abietis than conventional ones : Is plant chemistry the explanation?
- 2008
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Ingår i: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 23:4, s. 299-306
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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