Two infection sites of Hypoxylon mammatum in trembling aspen (Populus tremuloides)

1975 ◽  
Vol 53 (22) ◽  
pp. 2621-2624 ◽  
Author(s):  
Paul D. Manion
Keyword(s):  
Populus Tremuloides ◽  
Infection Site ◽  
Trembling Aspen ◽  
Naturally Occurring ◽  
Hypoxylon Mammatum ◽  
Common Infection

Observations and dissection of young naturally occurring cankers caused by Hypoxylon mammatum suggest that infection of second- and third-season-old stems and branches commonly takes place at the base of first- and second-season-old dead branches. A second but less common infection site is associated with galls caused by the insect Saperda concolor.

Germination of ascospores of Hypoxylon mammatum in living aspen

1972 ◽  
Vol 50 (9) ◽  
pp. 1973-1974 ◽  
Author(s):  
Darryl L. Anderson ◽  
D. W. French
Keyword(s):  
Incubation Period ◽  
Weather Conditions ◽  
Percentage Germination ◽  
Trembling Aspen ◽  
Naturally Occurring ◽  
Hypoxylon Mammatum

Ascospores of Hypoxylon mammatum germinated in the sapwood of naturally occurring trembling aspen. Observed germination never exceeded 7%. There appeared to be no clear relationships between percentage germination and the age of the wound, location in the sapwood, age of the tree, or weather conditions during the incubation period.

Wood-inhabiting microfungi isolated from Populus tremuloides from Alberta and northeastern British Columbia

1999 ◽  
Vol 77 (6) ◽  
pp. 898-905 ◽  
Author(s):  
Leonard J Hutchison
Keyword(s):  
British Columbia ◽  
Populus Tremuloides ◽  
Pure Culture ◽  
Healthy Tissue ◽  
Decayed Wood ◽  
Trembling Aspen ◽  
Aspen Wood ◽  
Hypoxylon Mammatum ◽  
Ophiostoma Piliferum

Forty-nine taxa of sporulating microfungi were isolated in pure culture from the bark and wood of living and recently cut stems of trembling aspen (Populus tremuloides) from several sites in central Alberta and northeastern British Columbia. Stems were either healthy, blue stained, or decayed, or else possessed cankers or black galls. Several ecological groupings of fungi were recognized, including wood-staining fungi (e.g., Ophiostoma piliferum), black-gall-associated fungi (e.g., Hyphozyma lignicola, Knufia cryptophialidica,Phoma etheridgei), canker-causing pathogens (e.g., Nectria cinnabarina, Tympanis spermatiospora, Valsa sordida), and fungi that could be referred to as endophytes. This latter group consisted of an assortment of fungi normally found in niches other than wood (e.g., Ciborinia whetzelii, Sporormiella similis), microfungi associated with decayed wood (e.g., Cryptosphaeria lignyota, Phialocephala fusca, Phialophora alba, Phialophora bubakii, or canker-causing fungi isolated from healthy tissue (e.g., Hypoxylon mammatum, Leucostoma nivea.Key words: microfungi, endophytes, Populus, aspen, wood, Ascomycota, hyphomycetes, coelomycetes.

Inoculation methods for selecting Populus tremuloides resistant to Hypoxylon canker

1999 ◽  
Vol 29 (8) ◽  
pp. 1192-1196 ◽  
Author(s):  
S A Enebak ◽  
M E Ostry ◽  
N A Anderson
Keyword(s):  
Populus Tremuloides ◽  
Callus Tissue ◽  
Time Frame ◽  
Breeding Program ◽  
Main Stem ◽  
Artificial Inoculation ◽  
Limited Time ◽  
Trembling Aspen ◽  
Inoculation Methods ◽  
Hypoxylon Mammatum

Canker expansion and the amount of callus tissue formed were measured monthly on 60 ramets from each of five trembling aspen (Populus tremuloides Michx.) clones that had been inoculated in wounds with Entoleuca mammata (= Hypoxylon mammatum (Wahl.) Mill.) over a 12-month period. At the clone level, the prevalence of nonlethal cankers within clones prior to the study had no correlation with canker expansion with three of the five clones. Greenhouse inoculation of ramets derived from the same five clones resulted in the same resistance rankings as main-stem inoculations in the field. One isolate, Hm-27, produced longer cankers, and less callus developed on all clones compared with trees inoculated with the less aggressive strain, Hm-24. Cankers developed only on clones that were inoculated during the months of April through July with April inoculations resulting in the largest cankers. These results indicate that there is a limited time frame when wounds on aspen are susceptible to infection by artificial inoculation with the pathogen as many wound inoculations neither produced cankers nor wound callus. Comparing inoculation methods, either main-stem inoculations in the field or greenhouse inoculations coupled with the natural canker prevalence could be used to include or exclude clones for use in an aspen breeding program.

scholarly journals Ethylene enhances root water transport and aquaporin expression in trembling aspen (Populus tremuloides) exposed to root hypoxia

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiangfeng Tan ◽  
Mengmeng Liu ◽  
Ning Du ◽  
Janusz J. Zwiazek
Keyword(s):  
Gas Exchange ◽  
Water Transport ◽  
Populus Tremuloides ◽  
Leaf Gas Exchange ◽  
Hydraulic Conductance ◽  
Root Hydraulic Conductance ◽  
Trembling Aspen ◽  
Expression Levels ◽  
Root Hypoxia ◽  
Exogenous Ethylene

Abstract Background Root hypoxia has detrimental effects on physiological processes and growth in most plants. The effects of hypoxia can be partly alleviated by ethylene. However, the tolerance mechanisms contributing to the ethylene-mediated hypoxia tolerance in plants remain poorly understood. Results In this study, we examined the effects of root hypoxia and exogenous ethylene treatments on leaf gas exchange, root hydraulic conductance, and the expression levels of several aquaporins of the plasma membrane intrinsic protein group (PIP) in trembling aspen (Populus tremuloides) seedlings. Ethylene enhanced net photosynthetic rates, transpiration rates, and root hydraulic conductance in hypoxic plants. Of the two subgroups of PIPs (PIP1 and PIP2), the protein abundance of PIP2s and the transcript abundance of PIP2;4 and PIP2;5 were higher in ethylene-treated trembling aspen roots compared with non-treated roots under hypoxia. The increases in the expression levels of these aquaporins could potentially facilitate root water transport. The enhanced root water transport by ethylene was likely responsible for the increase in leaf gas exchange of the hypoxic plants. Conclusions Exogenous ethylene enhanced root water transport and the expression levels of PIP2;4 and PIP2;5 in hypoxic roots of trembling aspen. The results suggest that ethylene facilitates the aquaporin-mediated water transport in plants exposed to root hypoxia.

The bacteria in sapwood, wetwood, and heartwood of trembling aspen (Populus tremuloides)

1973 ◽  
Vol 51 (2) ◽  
pp. 498-500 ◽  
Author(s):  
Donald M. Knutson
Keyword(s):  
Populus Tremuloides ◽  
Trembling Aspen ◽  
Indigenous Bacteria ◽  
Large Populations ◽  
Xylem Tissue

Bacteria (Erwinia, Bacillus) were consistently isolated from all samples of aspen sapwood and heartwood. In wetwood zones (water-soaked xylem tissue) or discolored heartwood, large populations often occur. No organisms unique to wetwood were isolated. Wetwood probably is formed by nonmicrobial means and, once formed, merely supports large populations of indigenous bacteria.

scholarly journals Impact du chancre hypoxylonien sur le tremble de 2 unités de gestion du Québec

1982 ◽  
Vol 58 (3) ◽  
pp. 139-142
Author(s):  
Louis Archambault
Keyword(s):  
Populus Tremuloides ◽  
Forest Stands ◽  
Management Units ◽  
Hypoxylon Mammatum ◽  
The Impact

A survey was conducted in the management units of Portneuf and Grand-Portage, Québec to determine the impact of Hypoxylon canker (Hypoxylon mammatum (Wahl.)) on aspen (Populus tremuloides Michx.). In 78 forest stands (2340 stems) of Portneuf, sampling revealed 2.6% of stems (2.0% of volume) affected or dead. In the 82 Grand-Portage stands (2460 stems) 4.1% of stems (2.8% of volume) were affected or dead. Other analyses were carried out on the frequency of the disease in relation to stand characteristics.Although annual losses which represent only a sixth of this evaluation are relatively low, we must emphasize that they are cumulative over the whole life of the stands. Moreover, the importance of the impact could increase if aspen was widely used.

Wounding of aspen roots promotes suckering

2004 ◽  
Vol 82 (3) ◽  
pp. 310-315 ◽  
Author(s):  
Erin C Fraser ◽  
Victor J Lieffers ◽  
Simon M Landhäusser
Keyword(s):  
Populus Tremuloides ◽  
Growth Rates ◽  
Growing Season ◽  
Organic Layer ◽  
Trembling Aspen ◽  
Layer Depth ◽  
Injury Type ◽  
Organic Layers ◽  
Root Injury ◽  
Root Sucker

In early May, 1-m sections of trembling aspen (Populus tremuloides Michx.) roots in a forest cutblock were carefully exposed and examined for damage. Undamaged roots were subjected to one of three wounding treatments (scrape, sever, or uninjured control) and were then reburied to either the full normal organic layer depth or to one third of the normal depth. Following one growing season, the roots were reexposed and assessed for aspen sucker numbers and growth rates. Results indicate that injured roots produced suckers nearly twice as often as uninjured roots. Further, injured roots produced more suckers per root, and these suckers were taller and had greater leaf area. Roots buried under shallow organic layers also generated more suckers, regardless of injury type. The side of injury (distal or proximal) did not affect any of the measured variables. The present study suggests that moderate wounding of aspen roots increases initial sucker numbers and growth rates.Key words: trembling aspen, root sucker, root injury, regeneration.

THE BEHAVIOUR OF FIVE WOOD SPECIES IN COMPRESSION

IAWA Journal ◽  
2002 ◽  
Vol 23 (2) ◽  
pp. 201-211 ◽  
Author(s):  
Simon Ellis ◽  
Paul Steiner
Keyword(s):  
Young’S Modulus ◽  
Populus Tremuloides ◽  
Wood Species ◽  
Young's Modulus ◽  
Douglas Fir ◽  
Thuja Plicata ◽  
Trembling Aspen ◽  
Moisture Contents ◽  
Red Cedar ◽  
Western Red Cedar

Five wood species, Oregon ash (Fraxinus latifolia Benth.), Balau (Shorea spp.), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), Western red cedar (Thuja plicata Donn ex D. Don), and Trembling aspen (Populus tremuloides Michx.) were loaded in compression longitudinally, radially and tangentially. The wood cubes were conditioned to one of four moisture contents prior to loading. Small cubes were loaded until no void space remained after which samples were released and soaked in water. Stress /strain curves were recorded over the whole range of strain and cube thicknesses were recorded at the end of the compression, after release from the testing apparatus, and after soaking in water. Denser woods resulted in a greater Young’s modulus, higher levels of stress and shorter time to densification than did less dense woods. Higher initial moisture contents apparently increased the plasticity of the wood leading to a lower Young’s modulus and lower levels of stress during compression, greater springback after release of stress and greater recovery after swelling in water. Differences observed in the radial and tangential behaviours were believed to be due to the supporting action of the rays when the wood was compressed in the radial direction in balau and trembling aspen and to the relative difference between the lower density earlywood and higher density latewood regions in ash, Douglas-fir and western red cedar.

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