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Halvor Solheim - One of the best experts on this subject based on the ideXlab platform.
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the ophiostoma clavatum species complex a newly defined group in the ophiostomatales including three novel taxa
Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology, 2016Co-Authors: Robert Jankowiak, Caterina Villari, Riikka Linnakoski, Halvor Solheim, Thomas Kirisits, Wilhelm Z De BeerAbstract:Two species of blue-Stain Fungi with similar morphologies, Ophiostoma brunneo-ciliatum and Ophiostoma clavatum, are associates of bark beetles infesting Pinus spp. in Europe. This has raised questions whether they represent distinct taxa. Absence of herbarium specimens and contaminated or mistakenly identified cultures of O. brunneo-ciliatum and O. clavatum have accentuated the uncertainty regarding their correct identification. The aim of this study was to reconsider the identity of European isolates reported as O. brunneo-ciliatum and O. clavatum by applying DNA-based identification methods, and to provide appropriate type specimens for them. Phylogenetic analyses of the ITS, βT, TEF-1α and CAL gene sequences revealed that the investigated isolates represent a complex of seven cryptic species. The study confirmed that ITS data is insufficient to delineate species in some Ophiostoma species clusters. Lectotypes and epitypes were designated for O. clavatum and O. brunneo-ciliatum, and three new species, Ophiostoma brunneolum, Ophiostoma macroclavatum and Ophiostoma pseudocatenulatum, are described in the newly defined O. clavatum-complex. The other two species included in the complex are Ophiostoma ainoae and Ophiostoma tapionis. The results suggest co-evolution of these Fungi in association with specific bark beetles. The results also confirm the identity of the fungus associated with the pine bark beetle Ips acuminatus as O. clavatum, while O. brunneo-ciliatum appears to be mainly associated with another pine bark beetle, Ips sexdentatus.
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effects of growth and virulence of associated blue Stain Fungi on host colonization behaviour of the pine shoot beetles tomicus minor and t piniperda
Plant Pathology, 2001Co-Authors: Halvor Solheim, Paal Krokene, Bo LangstromAbstract:The pine shoot beetles Tomicus minor and T. piniperda are common in the Nordic countries. Of these, T. piniperda may attack and kill living but severely stressed trees, whereas T. minor has never been reported to be individually responsible for killing live trees. Both species are associated with blue-Stain Fungi: T. minor with Ophiostoma canum and T. piniperda with Leptographium wingfieldii and Ophiostoma minus. The growth of these Fungi was studied in phloem and sapwood of live Scots pine trees, on malt agar, and on malt agar under oxygen-deficient conditions. Leptographium wingfieldii was more virulent (i.e. caused more extensive host symptoms) grew more quickly on malt agar, and was less affected by oxygen-deficient growth conditions than either O. minus or O. canum. Ophiostoma canum was least virulent. In low-density inoculations it induced lesions similar to those induced by sterile control inoculations; it grew very slowly on malt agar and stopped growing after <30 mm under oxygen-deficient conditions. Ophiostoma minus was intermediate in all respects. The different virulence of the blue-Stain Fungi associated with the two pine shoot beetles may explain the lower level of aggressiveness in T. minor.
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GROWTH AND VIRULENCE OF CERATOCYSTIS RUFIPENNI AND THREE BLUE-Stain Fungi ISOLATED FROM THE DOUGLAS-FIR BEETLE
Canadian Journal of Botany, 1998Co-Authors: Halvor Solheim, Paal KrokeneAbstract:Blue-Stain Fungi were isolated from the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, and from Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco, colonized by the beetle. Growth of the three most commonly isolated blue-Stain Fungi (Leptographium abietinum (Peck) Wingfield, Ophiostoma europhioides (Wright & Cain) Solheim, Ophiostoma pseudotsugae (Rumbold) von Arx), and Ceratocystis rufipenni Wingfield, Harrington, & Solheim, an important associate of the spruce beetle, Dendroctonus rufipennis (Kirby), was studied in sapwood and phloem of live Douglas-fir trees, on malt agar, and on malt agar under oxygen-deficient conditions. The two Ophiostoma species grew better in the phloem and induced longer phloem necroses than the other Fungi. Ceratocystis rufipenni and O. europhioides grew better in the sapwood and induced deeper sapwood occlusion. All Fungi were relatively fast growing on malt agar, with O. pseudotsugae growing fastest and L. abietinum, slowest. Growth of C. rufipenni and O. europhioides ...
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growth and virulence of mountain pine beetle associated blue Stain Fungi ophiostoma clavigerum and ophiostoma montium
Botany, 1998Co-Authors: Halvor Solheim, Paal KrokeneAbstract:The mountain pine beetle (Dendroctonus ponderosae) is commonly associated with the blue-Stain Fungi Ophiostoma clavigerum and Ophiostoma montium. Ophiostoma clavigerum is the primary invader of sapwood after beetle infestation and is thought to be the most virulent of the two Fungi. Growth of these Fungi was studied under oxygen-deficient conditions on malt agar in test tubes and Petri dishes. In addition, growth was studied in phloem and sapwood of young living shore pines (Pinus contorta var. contorta) and western white pines (Pinus monticola) inoculated with fungus in low densities (eight inoculations per tree). In test tubes with limited oxygen O. clavigerum grew for a longer time than O. montium. Both Fungi are fast growing on malt agar (maximum growth 4.4n9.0 mm/day), but O. clavigerum grew better at temperatures below 25∞C. The rapid growth and the ability to tolerate low oxygen levels may be important adaptations for O. clavigerum as the primary invader of fresh sapwood. However, although O. clavigerum grew better in the phloem of both tree species, there were no differences between the two Fungi in their ability to colonize the sapwood of the inoculated trees.
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growth and virulence of mountain pine beetle associated blue Stain Fungi ophiostoma clavigerum and ophiostoma montium
Botany, 1998Co-Authors: Halvor Solheim, Paal KrokeneAbstract:The mountain pine beetle (Dendroctonus ponderosae) is commonly associated with the blue-Stain Fungi Ophiostoma clavigerum and Ophiostoma montium. Ophiostoma clavigerum is the primary invader of sap...
Paal Krokene - One of the best experts on this subject based on the ideXlab platform.
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Convergent evolution of semiochemicals across Kingdoms: bark beetles and their fungal symbionts
The ISME Journal, 2019Co-Authors: Tao Zhao, Suresh Ganji, Christian Schiebe, Björn Bohman, Paal Krokene, Philip Weinstein, Anna-karin Borg-karlson, C. Rikard UneliusAbstract:Convergent evolution of semiochemical use in organisms from different Kingdoms is a rarely described phenomenon. Tree-killing bark beetles vector numerous symbiotic blue-Stain Fungi that help the beetles colonize healthy trees. Here we show for the first time that some of these Fungi are able to biosynthesize bicyclic ketals that are pheromones and other semiochemicals of bark beetles. Volatile emissions of five common bark beetle symbionts were investigated by gas chromatography-mass spectrometry. When grown on fresh Norway spruce bark the Fungi emitted three well-known bark beetle aggregation pheromones and semiochemicals (exo-brevicomin, endo-brevicomin and trans-conophthorin) and two structurally related semiochemical candidates (exo-1,3-dimethyl-2,9-dioxabicyclo[3.3.1]nonane and endo-1,3-dimethyl-2,9-dioxabicyclo[3.3.1]nonane) that elicited electroantennogram responses in the spruce bark beetle Ips typographus. When grown on malt agar with 13C d-Glucose, the fungus Grosmannia europhioides incorporated 13C into exo-brevicomin and trans-conophthorin. The enantiomeric compositions of the fungus-produced ketals closely matched those previously reported from bark beetles. The production of structurally complex bark beetle pheromones by symbiotic Fungi indicates cross-kingdom convergent evolution of signal use in this system. This signaling is susceptible to disruption, providing potential new targets for pest control in conifer forests and plantations.
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Table_1_Bark Beetle-Associated Blue-Stain Fungi Increase Antioxidant Enzyme Activities and Monoterpene Concentrations in Pinus yunnanensis.doc
2018Co-Authors: Yue Pan, Paal Krokene, Tao Zhao, Min Qiao, Peng ChenAbstract:Yunnan pine is the most important tree species in SW China in both economical and ecological terms, but it is often killed by pine shoot beetles (Tomicus spp.). Tomicus beetles are secondary pests in temperate regions and the aggressiveness of the beetles in SW China is considered to be due to the warm subtropical climates as well as the beetles’ virulent fungal associates. Here, we assessed the virulence of three blue-Stain Fungi (Leptographium wushanense, L. sinense and Ophiostoma canum) associated with pine shoot beetles to Yunnan pine (Pinus yunnanensis) in SW China. Following fungal inoculation, we measured necrotic lesion lengths, antioxidant enzyme activities and monoterpene concentrations in the stem phloem of Yunnan pine. Leptographium wushanense induced twice as long lesions as L. sinense and O. canum, and all three Fungi induced significantly longer lesions than sterile agar control inoculations. The activity of three tested antioxidant enzymes (peroxidase, polyphenol oxidase, and superoxide dismutase) increased after both fungal inoculation and control inoculation. However, L. wushanense and L. sinense generally caused a greater increase in enzyme activities than O. canum and the control treatment. Fungal inoculation induced stronger increases in six major monoterpenes than the control treatment, but the difference was significant only for some fungus-monoterpene combinations. Overall, our results show that L. wushanense and L. sinense elicit stronger defense responses and thus are more virulent to Yunnan pine than O. canum. The two Leptographium species may thus contribute to the aggressiveness of their beetle vectors and could damage Yunnan pine across SW China if they spread from the restricted geographical area they have been found in so far.
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Image_1_Bark Beetle-Associated Blue-Stain Fungi Increase Antioxidant Enzyme Activities and Monoterpene Concentrations in Pinus yunnanensis.JPEG
2018Co-Authors: Yue Pan, Paal Krokene, Tao Zhao, Min Qiao, Peng ChenAbstract:Yunnan pine is the most important tree species in SW China in both economical and ecological terms, but it is often killed by pine shoot beetles (Tomicus spp.). Tomicus beetles are secondary pests in temperate regions and the aggressiveness of the beetles in SW China is considered to be due to the warm subtropical climates as well as the beetles’ virulent fungal associates. Here, we assessed the virulence of three blue-Stain Fungi (Leptographium wushanense, L. sinense and Ophiostoma canum) associated with pine shoot beetles to Yunnan pine (Pinus yunnanensis) in SW China. Following fungal inoculation, we measured necrotic lesion lengths, antioxidant enzyme activities and monoterpene concentrations in the stem phloem of Yunnan pine. Leptographium wushanense induced twice as long lesions as L. sinense and O. canum, and all three Fungi induced significantly longer lesions than sterile agar control inoculations. The activity of three tested antioxidant enzymes (peroxidase, polyphenol oxidase, and superoxide dismutase) increased after both fungal inoculation and control inoculation. However, L. wushanense and L. sinense generally caused a greater increase in enzyme activities than O. canum and the control treatment. Fungal inoculation induced stronger increases in six major monoterpenes than the control treatment, but the difference was significant only for some fungus-monoterpene combinations. Overall, our results show that L. wushanense and L. sinense elicit stronger defense responses and thus are more virulent to Yunnan pine than O. canum. The two Leptographium species may thus contribute to the aggressiveness of their beetle vectors and could damage Yunnan pine across SW China if they spread from the restricted geographical area they have been found in so far.
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Bark Beetle-Associated Blue-Stain Fungi Increase Antioxidant Enzyme Activities and Monoterpene Concentrations in Pinus yunnanensis
Frontiers Media S.A., 2018Co-Authors: Paal Krokene, Tao Zhao, Yue Pan, Min Qiao, Peng ChenAbstract:Yunnan pine is the most important tree species in SW China in both economical and ecological terms, but it is often killed by pine shoot beetles (Tomicus spp.). Tomicus beetles are secondary pests in temperate regions and the aggressiveness of the beetles in SW China is considered to be due to the warm subtropical climates as well as the beetles’ virulent fungal associates. Here, we assessed the virulence of three blue-Stain Fungi (Leptographium wushanense, L. sinense and Ophiostoma canum) associated with pine shoot beetles to Yunnan pine (Pinus yunnanensis) in SW China. Following fungal inoculation, we measured necrotic lesion lengths, antioxidant enzyme activities and monoterpene concentrations in the stem phloem of Yunnan pine. Leptographium wushanense induced twice as long lesions as L. sinense and O. canum, and all three Fungi induced significantly longer lesions than sterile agar control inoculations. The activity of three tested antioxidant enzymes (peroxidase, polyphenol oxidase, and superoxide dismutase) increased after both fungal inoculation and control inoculation. However, L. wushanense and L. sinense generally caused a greater increase in enzyme activities than O. canum and the control treatment. Fungal inoculation induced stronger increases in six major monoterpenes than the control treatment, but the difference was significant only for some fungus-monoterpene combinations. Overall, our results show that L. wushanense and L. sinense elicit stronger defense responses and thus are more virulent to Yunnan pine than O. canum. The two Leptographium species may thus contribute to the aggressiveness of their beetle vectors and could damage Yunnan pine across SW China if they spread from the restricted geographical area they have been found in so far
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anatomical and chemical defenses of conifer bark against bark beetles and other pests
New Phytologist, 2005Co-Authors: Vincent R. Franceschi, Paal Krokene, Erik Christiansen, Trygve KreklingAbstract:Contents Summary 1 I. Introduction 2 II. Integrating defense strategies 2 III. Constitutive defense systems: first tier of defense 4 IV. Inducible defense systems: second tier of defense 11 V. Genetics and physiology of bark defense 13 VI. Bark beetles: diminutive but deadly 15 VII. The arms race: coevolution of conifer defense and bark beetle strategies 15 VIII. Bark-beetle-vectored blue-Stain Fungi: multiple attacks against multiple defenses 17 IX. Conclusions 18 Acknowledgements 19 References 19 Summary Conifers are long-lived organisms, and part of their success is due to their potent defense mechanisms. This review focuses on bark defenses, a front line against organisms trying to reach the nutrient-rich phloem. A major breach of the bark can lead to tree death, as evidenced by the millions of trees killed every year by specialized bark-invading insects. Different defense strategies have arisen in conifer lineages, but the general strategy is one of overlapping constitutive mechanical and chemical defenses overlaid with the capacity to up-regulate additional defenses. The defense strategy incorporates a graded response from ‘repel’, through ‘defend’ and ‘kill’, to ‘compartmentalize’, depending upon the advance of the invading organism. Using a combination of toxic and polymer chemistry, anatomical structures and their placement, and inducible defenses, conifers have evolved bark defense mechanisms that work against a variety of pests. However, these can be overcome by strategies including aggregation pheromones of bark beetles and introduction of virulent phytopathogens. The defense structures and chemicals in conifer bark are reviewed and questions about their coevolution with bark beetles are discussed.
Adrianne V Rice - One of the best experts on this subject based on the ideXlab platform.
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multilocus species identification and fungal dna barcoding insights from blue Stain fungal symbionts of the mountain pine beetle
Molecular Ecology Resources, 2010Co-Authors: Adrianne V Rice, Sean E Bromilow, Janice E K Cooke, Felix A H SperlingAbstract:There is strong community-wide interest in applying molecular techniques to fungal species delimitation and identification, but selection of a standardized region or regions of the genome has not been finalized. A single marker, the ribosomal DNA internal transcribed spacer region, has frequently been suggested as the standard for Fungi. We used a group of closely related blue Stain Fungi associated with the mountain pine beetle (Dendroctonus ponderosae Hopkins) to examine the success of such single-locus species identification, comparing the internal transcribed spacer with four other nuclear markers. We demonstrate that single loci varied in their utility for identifying the six fungal species examined, while use of multiple loci was consistently successful. In a literature survey of 21 similar studies, individual loci were also highly variable in their ability to provide consistent species identifications and were less successful than multilocus diagnostics. Accurate species identification is the essence of any molecular diagnostic system, and this consideration should be central to locus selection. Moreover, our study and the literature survey demonstrate the value of using closely related species as the proving ground for developing a molecular identification system. We advocate use of a multilocus barcode approach that is similar to the practice employed by the plant barcode community, rather than reliance on a single locus.
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mountain pine beetle associated blue Stain Fungi in lodgepole jack pine hybrids near grande prairie alberta canada
Forest Pathology, 2009Co-Authors: Adrianne V Rice, David W. LangorAbstract:Summary The mountain pine beetle (MPB), the most serious pest of lodgepole pine in mountainous western Canada, spread northeastward into lodgepole · jack pine hybrids in the boreal forest of Alberta in 2006. The MPB vectors three species of blue-Stain Fungi, which contribute to the success of the beetles. These Fungi were isolated from MPB larvae and galleries in several lodgepole · jack pine stands in the Grande Prairie region of northwestern Alberta in autumn 2006 and winter and spring 2007. Fungi were recovered from more than 95% of gallery systems. The three Fungi were similarly prevalent but Ophiostoma montium was the most frequently isolated fungus at each sampling point, isolated from 72% to 90% of gallery systems compared with 63% to 78% for Grosmannia clavigera, and 61% to 86% for Leptographium longiclavatum. Ophiostoma montium and G. clavigera were isolated from more larvae than gallery samples, with the opposite true for L. longiclavatum. Most gallery systems contained multiple Fungi with three Fungi per gallery system being more common in autumn and winter and two Fungi more common in the spring. The combination of G. clavigera and L. longiclavatum was less common among gallery systems with two Fungi than either of the pairwise combinations containing O. montium. Fungal prevalence was the same above and below snow level. The prevalence of the three Fungi did not differ significantly among stands sampled in the spring but stands with more G. clavigera tended to have less L. longiclavatum. The winter of 2006‐2007 was colder than average throughout Alberta with temperatures below )30� C in November, January and February, and all three Fungi were present after the cold winter while most larvae had died, suggesting that overwintering mortality of the Fungi will not limit persistence and spread of MPB in the boreal forest.
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mountain pine beetle associated blue Stain Fungi are differentially adapted to boreal temperatures
Forest Pathology, 2008Co-Authors: Adrianne V Rice, Markus N. Thormann, David W. LangorAbstract:Summary Mountain pine beetles (MPB) are the most serious pest of lodgepole pine in Canada and are likely to invade boreal jack pine forests. MPB vector three blue-Stain Fungi, Grosmannia clavigera, Ophiostoma montium and Leptographium longiclavatum, which contribute to beetle success. Fungal survival at extreme boreal temperatures will contribute to their success in jack pine. Growth, sporulation and survival of the three Fungi at )20 to 37� C were tested in vitro. Overwintering survival of G. clavigera and O. montium was assessed in vivo. All species grew at 5–30� C, with optimal growth at 20–25� C. Grosmannia clavigera and L. longiclavatum survived at )20� C, but O. montium died. Growth of G. clavigera and L. longiclavatum was inhibited at 30� C, but O. montium grew well. Grosmannia clavigera and O. montium overwintered in living pines. These results suggest that G. clavigera and L. longiclavatum were adapted to cold boreal winters but not hot summers, with the converse true for O. montium. Temperature tolerance varied among G. clavigera isolates. British Columbian and Californian isolates grew faster at 25� C than Albertan isolates. Isolates from Alberta and Idaho ⁄ Montana grew optimally at 20� C, while British Columbian and Californian isolates grew optimally at 25� C.
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virulence of and interactions among mountain pine beetle associated blue Stain Fungi on two pine species and their hybrids in alberta
Botany, 2007Co-Authors: Adrianne V Rice, Markus N. Thormann, David W. LangorAbstract:Mountain pine beetle (MPB) is the most serious pest of lodgepole pine in western Canada, and it is predicted to spread into boreal jack pine within the next few years. Colonization of host trees by...
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Mountain pine beetle associated blue-Stain Fungi cause lesions on jack pine, lodgepole pine, and lodgepole × jack pine hybrids in Alberta
Botany, 2007Co-Authors: Adrianne V Rice, Markus N. Thormann, David W. LangorAbstract:Mountain pine beetles (Dendroctonus ponderosae Hopkins; (MPB)) have spread into lodgepole jack pine hy- brid (Pinus contorta Douglas Pinus banksiana Lambert) forests in Alberta and are predicted to spread into jack pine for- ests. Their success in these forests is uncertain but will be influenced by multiple factors, including the ability of their associated blue-Stain Fungi to colonize the trees and the health of the encountered trees. Healthy and dwarf mistletoe in- fected pines at three sites across Alberta (one site per pine species) were inoculated with three isolates each of Grosmannia clavigera (Robinson-Jeffrey and Davidson) Zipfel, de Beer and Wingfield and Ophiostoma montium (Rumbold) von Arx. Both Fungi grew and caused lesions on all hosts, suggesting that MPB will not be limited by a lack of fungal growth. Both Fungi caused longer lesions in jack and hybrid pines than in lodgepole pines, indicating that susceptibility varies among hosts and is greater in the novel systems than in the co-evolved one. G. clavigera caused longer lesions than O. montium in hybrids and lodgepole pines, while the two species caused similar-sized lesions on jack pine. Intraspecific variation was high in G. clavigera, with one isolate producing much shorter lesions than the other two. Dwarf mistletoe infestation had little effect on infection lesion length.
Roberta L Farrell - One of the best experts on this subject based on the ideXlab platform.
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biological control of blue Stain Fungi on populus tremuloides using selected ophiostoma isolates
Holzforschung, 1998Co-Authors: Wendy J Whitemcdougall, Roberta L Farrell, Robert A BlanchetteAbstract:Single ascospore isolates of Ophiostoma piceae and O. pluriannulatum were selected for lack of hyphal pigmentation and their inability to Stain aspen wood. Several colorless strains were tested in laboratory and field studies for their potential to control sapStain in aspen wood. A previously selected and commercially available fungus used in biopulping processes. Cartapip-97, was also tested for controlling Stain Fungi. The colorless Ophiostoma isolates successfully prevented Staining of sterile wood in the laboratory when challenged by a wild type Staining isolate of 0. pluriannulatum. The colorless strains also aggressively colonized nonsterile aspen wood in laboratory and field trials and significantly reduced sapStain. In the field trials. colorless isolates significantly reduced colonization of wild type Ophiostema species by as much as 75 % and reduced colonization in logs challenged with an aggressive wild type sapStain fungus by 37 to 58 %. Aspen logs treated with colorless strains were visually free of sapStain. Wood extractives were also significantly reduced by 28 to 33 % after treatment with colorless strains as compared to fresh, untreated wood.
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biological control of blue Stain Fungi in wood
Phytopathology, 1995Co-Authors: Chad J Behrendt, Robert A Blanchette, Roberta L FarrellAbstract:Biological control of blue-Stain Fungi, such as Ophiostoma spp., that are detrimental to the wood products industry, was demonstrated in laboratory and field trials by a colorless strain of O. piliferum. Cartapip-97. This strain lacks melaninlike compounds responsible for the discoloration of sapwood. Inoculation of logs with Cartapip in the laboratory 2 wk before challenging with other Fungi resulted in 58-68% colonization for Cartapip in isolated wood chips, while O. piliferum. O. piceae, O. minus, Phanerochaete gigantea, or Trichoderma harzianum colonized 0, 0, 0, 0, and 61%, respectively. Inoculation of logs with Cartapip 4 wk before other Fungi resulted in similar trends with strong inhibition of blue-Stain Fungi. Simultaneous inoculation of logs with Cartapip and other Fungi resulted in decreased colonization by both Cartapip and Ophiostoma species. When blue-Stain Fungi, P. gigantea or T. harzianum were inoculated 2 wk before Cartapip, colonization for these Fungi ranged from 19 to 64% in cultured wood chips, whereas Cartapip ranged from 0 to 45% among the different treatments. Inoculation of O. piliferum and O. piceae prior to Cartapip resulted in inhibition of Cartapip. Two field trials demonstrated the exclusion of blue-Stain Fungi with prior colonization of the sapwood by Cartapip. Four weeks after inoculation of logs in the field, 92-100% of cultured wood chips were colonized by Cartapip in both trials, while blue-Stain Fungi colonized only 0-8%. In contrast, blue-Stain Fungi colonized 63% of the cultured wood chips in untreated control logs during the first field trial, and 29 and 71% for untreated control and antitranspirant treatments, respectively, during the second field trial. Results from both laboratory and field trials show the effectiveness of Cartapip for protecting freshly cut wood from blue-Stain Fungi
David W. Langor - One of the best experts on this subject based on the ideXlab platform.
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mountain pine beetle associated blue Stain Fungi in lodgepole jack pine hybrids near grande prairie alberta canada
Forest Pathology, 2009Co-Authors: Adrianne V Rice, David W. LangorAbstract:Summary The mountain pine beetle (MPB), the most serious pest of lodgepole pine in mountainous western Canada, spread northeastward into lodgepole · jack pine hybrids in the boreal forest of Alberta in 2006. The MPB vectors three species of blue-Stain Fungi, which contribute to the success of the beetles. These Fungi were isolated from MPB larvae and galleries in several lodgepole · jack pine stands in the Grande Prairie region of northwestern Alberta in autumn 2006 and winter and spring 2007. Fungi were recovered from more than 95% of gallery systems. The three Fungi were similarly prevalent but Ophiostoma montium was the most frequently isolated fungus at each sampling point, isolated from 72% to 90% of gallery systems compared with 63% to 78% for Grosmannia clavigera, and 61% to 86% for Leptographium longiclavatum. Ophiostoma montium and G. clavigera were isolated from more larvae than gallery samples, with the opposite true for L. longiclavatum. Most gallery systems contained multiple Fungi with three Fungi per gallery system being more common in autumn and winter and two Fungi more common in the spring. The combination of G. clavigera and L. longiclavatum was less common among gallery systems with two Fungi than either of the pairwise combinations containing O. montium. Fungal prevalence was the same above and below snow level. The prevalence of the three Fungi did not differ significantly among stands sampled in the spring but stands with more G. clavigera tended to have less L. longiclavatum. The winter of 2006‐2007 was colder than average throughout Alberta with temperatures below )30� C in November, January and February, and all three Fungi were present after the cold winter while most larvae had died, suggesting that overwintering mortality of the Fungi will not limit persistence and spread of MPB in the boreal forest.
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mountain pine beetle associated blue Stain Fungi are differentially adapted to boreal temperatures
Forest Pathology, 2008Co-Authors: Adrianne V Rice, Markus N. Thormann, David W. LangorAbstract:Summary Mountain pine beetles (MPB) are the most serious pest of lodgepole pine in Canada and are likely to invade boreal jack pine forests. MPB vector three blue-Stain Fungi, Grosmannia clavigera, Ophiostoma montium and Leptographium longiclavatum, which contribute to beetle success. Fungal survival at extreme boreal temperatures will contribute to their success in jack pine. Growth, sporulation and survival of the three Fungi at )20 to 37� C were tested in vitro. Overwintering survival of G. clavigera and O. montium was assessed in vivo. All species grew at 5–30� C, with optimal growth at 20–25� C. Grosmannia clavigera and L. longiclavatum survived at )20� C, but O. montium died. Growth of G. clavigera and L. longiclavatum was inhibited at 30� C, but O. montium grew well. Grosmannia clavigera and O. montium overwintered in living pines. These results suggest that G. clavigera and L. longiclavatum were adapted to cold boreal winters but not hot summers, with the converse true for O. montium. Temperature tolerance varied among G. clavigera isolates. British Columbian and Californian isolates grew faster at 25� C than Albertan isolates. Isolates from Alberta and Idaho ⁄ Montana grew optimally at 20� C, while British Columbian and Californian isolates grew optimally at 25� C.
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virulence of and interactions among mountain pine beetle associated blue Stain Fungi on two pine species and their hybrids in alberta
Botany, 2007Co-Authors: Adrianne V Rice, Markus N. Thormann, David W. LangorAbstract:Mountain pine beetle (MPB) is the most serious pest of lodgepole pine in western Canada, and it is predicted to spread into boreal jack pine within the next few years. Colonization of host trees by...
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Mountain pine beetle associated blue-Stain Fungi cause lesions on jack pine, lodgepole pine, and lodgepole × jack pine hybrids in Alberta
Botany, 2007Co-Authors: Adrianne V Rice, Markus N. Thormann, David W. LangorAbstract:Mountain pine beetles (Dendroctonus ponderosae Hopkins; (MPB)) have spread into lodgepole jack pine hy- brid (Pinus contorta Douglas Pinus banksiana Lambert) forests in Alberta and are predicted to spread into jack pine for- ests. Their success in these forests is uncertain but will be influenced by multiple factors, including the ability of their associated blue-Stain Fungi to colonize the trees and the health of the encountered trees. Healthy and dwarf mistletoe in- fected pines at three sites across Alberta (one site per pine species) were inoculated with three isolates each of Grosmannia clavigera (Robinson-Jeffrey and Davidson) Zipfel, de Beer and Wingfield and Ophiostoma montium (Rumbold) von Arx. Both Fungi grew and caused lesions on all hosts, suggesting that MPB will not be limited by a lack of fungal growth. Both Fungi caused longer lesions in jack and hybrid pines than in lodgepole pines, indicating that susceptibility varies among hosts and is greater in the novel systems than in the co-evolved one. G. clavigera caused longer lesions than O. montium in hybrids and lodgepole pines, while the two species caused similar-sized lesions on jack pine. Intraspecific variation was high in G. clavigera, with one isolate producing much shorter lesions than the other two. Dwarf mistletoe infestation had little effect on infection lesion length.
