Pathogenicity of the blue-stain fungi Leptographiumwingfieldii and Ophiostomaminus to Scots pine: effect of tree pruning and inoculum density

1993 ◽  
Vol 23 (7) ◽  
pp. 1438-1443 ◽  
Author(s):  
Halvor Solheim ◽  
Bo Långström ◽  
Claes Hellqvist

The pathogenicity of the blue-stain fungi Leptographiumwingfieldii Morelet and Ophiostomaminus (Hedge.) H. et P. Syd., associated with the pine shoot beetle Tomicuspiniperda (L.), was determined on pruned and unpruned Scots pine (Pinussylvestris L.) trees. Both fungi killed unpruned trees when inoculated in a 60 cm wide band at a density of 800 inoculations/m2, while severely pruned trees were killed by an inoculation density of 400 inoculations/m2. Trees inoculated with L. wingfieldii died sooner after inoculation than trees inoculated with O. minus.

Biologia ◽  
2018 ◽  
Vol 73 (11) ◽  
pp. 1053-1066 ◽  
Author(s):  
Katarína Pastirčáková ◽  
Katarína Adamčíková ◽  
Martin Pastirčák ◽  
Peter Zach ◽  
Juraj Galko ◽  
...  

1998 ◽  
Vol 88 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Paal Krokene ◽  
Halvor Solheim

The pathogenicity of two isolates of each of four bark beetle-associated blue-stain fungi was evaluated after mass inoculation of about 40-year-old Norway spruce trees (Picea abies). Trees were inoculated with a different isolate of each fungus in 1995 and 1996 at a density of 400 inoculations per m2 in a 1.2-m-wide band on the lower bole (about 270 inoculations per tree). Trees were felled 15 weeks after inoculation. In 1995, Ceratocystis polonica was the only fungus that had stained the sapwood (56.3% of cross-sectional sapwood area). It induced five times longer phloem necroses, 21 times more dead cambium, and 11 times more dead phloem than any other fungus. In 1996, C. polonica induced less extensive host symptoms and an unidentified Ambrosiella sp. induced comparable symptoms to C. polonica in the phloem and cambium. No trees showed any foliar symptoms 15 weeks after inoculation, but six out of eight trees inoculated with C. polonica in 1995 had only 0 to 25% functional sapwood and probably would have died if felling had been delayed. This study confirms that C. polonica, an associate of the aggressive bark beetle Ips typographus, is pathogenic to Norway spruce. The pathogenicity of the Ambrosiella sp., which is associated with a nonaggressive bark beetle, seems moderate and varies between isolates. The two remaining fungi included in this study (Ophiostoma piceae and a dark fungus with sterile mycelium), which are associated with nonaggressive bark beetles, were nonpathogenic in both experiments. These results are consistent with the hypothesis that aggressive bark beetle species vector virulent fungi that may help them kill trees, but the results also show that some nonaggressive bark beetles may vector phytopathogenic fungi.


2021 ◽  
Author(s):  
Robert Jankowiak ◽  
Grzegorz Szewczyk ◽  
Piotr Bilański ◽  
Dominika Jazłowiecka ◽  
Beata Harabin ◽  
...  

2021 ◽  
Vol 9 (8) ◽  
pp. 1641
Author(s):  
Javier E. Mercado ◽  
Beatriz Ortiz-Santana ◽  
Shannon L. Kay

Fungal and mite associates may drive changes in bark beetle populations, and mechanisms constraining beetle irruptions may be hidden in endemic populations. We characterized common fungi of endemic-level Jeffrey pine beetle (JPB) in western USA and analyzed their dissemination by JPB (maxillae and fecal pellet) and fungivorous mites to identify if endogenous regulation drove the population. We hypothesized that: (1) as in near-endemic mountain pine beetle populations, JPB’s mutualistic fungus would either be less abundant in endemic than in non-endemic populations or that another fungus may be more prevalent; (2) JPB primarily transports its mutualistic fungus, while its fungivorous mites primarily transport another fungus, and (3) based on the prevalence of yeasts in bark beetle symbioses, that a mutualistic interaction with blue-stain fungi present in that system may exist. Grosmannia clavigera was the most frequent JPB symbiont; however, the new here reported antagonist, Ophiostoma minus, was second in frequency. As hypothesized, JPB mostly carried its mutualist fungus while another fungus (i.e., antagonistic) was mainly carried by mites, but no fungal transport was obligate. Furthermore, we found a novel mutualistic interaction between the yeast Kuraishia molischiana and G. clavigera which fostered a growth advantage at temperatures associated with beetle colonization.


Holzforschung ◽  
2015 ◽  
Vol 69 (5) ◽  
pp. 595-601 ◽  
Author(s):  
Jan C. Namyslo ◽  
Dieter E. Kaufmann ◽  
Carsten Mai ◽  
Holger Militz

Abstract The development of appropriate chemical precursors that can covalently functionalize natural wood aims at efficient restriction of deterioration. Biological staining experiments were performed with veneer pieces made of sapwood of Scots pine (Pinus sylvestris L.) that had previously been chemically modified with substituted benzoates. Based on the recently published protocol on esterification of wood by means of 1H-benzotriazole activation, the quantity of covalently bonded organomaterials (QCOs), a recently defined advantageous value considering the individual molecular weight of the functionalizing organochemical groups, was obtained in the range of 0.9–1.5 mmol g-1. The modified wood was analyzed by attenuated total reflection IR spectroscopy. Modification with three electronically different benzoates clearly reduced the colonization of the specimen’s surfaces by the blue stain fungus Aureobasidium pullulans but did not fully prevent it. The degree of colonization appeared to decrease with increasing QCO values of the modification agents but apparently did not strongly depend on the additional functionality of the benzoate.


Forests ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 488 ◽  
Author(s):  
Davor Kržišnik ◽  
Boštjan Lesar ◽  
Nejc Thaler ◽  
Miha Humar

The importance of the aesthetic performance of wood is increasing and the colour is one of the most important parameters of aesthetics, hence the colour stability of twelve different wood-based materials was evaluated by several in-service and laboratory tests. The wood used for wooden façades and decking belongs to a group of severely exposed surfaces. Discolouration of wood in such applications is a long-known phenomenon, which is a result of different biotic and abiotic causes. The ongoing in-service trial started in October 2013, whilst a laboratory test mimicking seasonal exposure was performed in parallel. Samples were exposed to blue stain fungi (Aureobasidium pullulans and Dothichiza pithyophila) in a laboratory test according to the EN 152 procedure. Afterwards, the same samples were artificially weathered and re-exposed to the same blue stain fungi for the second time. The purpose of this experiment was to investigate the synergistic effect of weathering and staining. The broader aim of the study was to determine the correlation factors between artificial and natural weathering and to compare laboratory and field test data of fungal disfigurement of various bio-based materials. During the four years of exposure, the most prominent colour changes were determined on decking. Respective changes on the façade elements were significantly less prominent, being the lest evident on the south and east façade. The results showed that there are positive correlations between natural weathering and the combination of artificial weathering and blue staining. Hence, the artificial weathering of wood-based materials in the laboratory should consist of two steps, blue staining and artificial weathering, in order to simulate colour changes.


2015 ◽  
Vol 143 (4) ◽  
pp. 627-639 ◽  
Author(s):  
Mally Dori-Bachash ◽  
Liat Avrahami-Moyal ◽  
Alex Protasov ◽  
Zvi Mendel ◽  
Stanley Freeman

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