Interactions between Norway spruce (Picea abies) and Heterobasidion annosum. II. Infection of woody roots

1994 ◽  
Vol 72 (6) ◽  
pp. 884-889 ◽  
Author(s):  
W. K. Heneen ◽  
M. Gustafsson ◽  
K. Brismar ◽  
G. Karlsson
Keyword(s):  
Electron Microscopy ◽  
Picea Abies ◽  
Norway Spruce ◽  
Chemical Defence ◽  
Heterobasidion Annosum ◽  
Root Infection ◽  
Defence Mechanisms ◽  
Fungal Hyphae ◽  
Inner Parts ◽  
Scanning Electron

Woody roots, 2 – 4 mm in diameter, of Norway spruce (Picea abies) were inoculated with an S strain of Heterobasidion annosum. After 8 – 20 days the roots were prepared for examination by light microscopy as well as transmission and scanning electron microscopy. The roots had one or several periderms and sometimes remnant cortex cells on the surface. The fungal infection was restricted to the remnant cortex cells and the rhytidome after an incubation period of 20 days. Accumulation of granular materials, most likely phenolic in nature, prevailed in the infected periderm cells. Fungal hyphae enclosed in these materials showed signs of degeneration. Based on these results, we conclude that the rhytidome acts as a successful barrier to infection of the inner parts of the root for at least 20 days following inoculation with H. annosum. Both structural and chemical defence mechanisms are involved. Key words: Norway spruce, Heterobasidion annosum, root infection, woody roots, microscopy.

Interactions between Norway spruce (Picea abies) and Heterobasidion annosum. I. Infection of nonsuberized and young suberized roots

1994 ◽  
Vol 72 (6) ◽  
pp. 872-883 ◽  
Author(s):  
W. K. Heneen ◽  
M. Gustafsson ◽  
G. Karlsson ◽  
K. Brismar
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Cell Walls ◽  
Heterobasidion Annosum ◽  
Root Infection ◽  
Host Reaction ◽  
Outer Cortex ◽  
Fungal Enzymes ◽  
Transmission Electron ◽  
Inner Cortex

Nonsuberized and young suberized roots of Norway spruce (Picea abies) were inoculated with an S-strain of Heterobasidion annosum for 2–20 days. The roots were sectioned for light microscopy and transmission electron microscopy. They were susceptible to infection at both stages of development. The host reaction to delimit the infection was the formation of a necrotic ring barrier in the outer cortex. In cases where the inner cortex also became infected, fungal hyphae accumulated just before the endodermis, which acted as a new barrier. Only in nonsuberized roots did the hyphae succeed in penetrating the stele, and within 3 days after inoculation the stele was almost completely digested. Other resistance reactions included accumulation of phenolic deposits, secondary thickening of cell walls, and formation of papillae. The hyphae were able to grow within and across cell walls. The presence of translucent areas around penetrating hyphae possibly reflected the digestive action of fungal enzymes. The hyphae showed signs of degeneration when entrapped in encompassing cellular deposits. Key words: Norway spruce, Heterobasidion annosum, root infection, nonsuberized roots, young suberized roots, microscopy.

Internal hyphae in young, symptomless needles of Picea abies: electron microscopic and cultural investigation

1987 ◽  
Vol 65 (10) ◽  
pp. 2098-2103 ◽  
Author(s):  
Jürgen Suske ◽  
Georg Acker
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Fungal Endophytes ◽  
Infection Rates ◽  
Electron Microscopic ◽  
Fungal Hyphae ◽  
Living Tissues ◽  
Spruce Needles ◽  
Host Tissues ◽  
Scanning Electron

Results from cultural investigations were correlated with scanning electron microscope observations and give an introduction to the interaction of endophytic hyphae of Lophodermium piceae (Fckl.) Höhn. and other fungi with living tissues of green, symptomless needles of Norway spruce (Picea abies Karst.). The frequency of endophytic needle fungi was determined by the culture of surface-sterilized needles harvested from two trees. Lophodermium piceae was found to be the most important colonizer of symptomless needles; the infection rates ranged from about 3 to 7%. The presence of fungal hyphae in living needle tissues of symptomless, current year and older Norway spruce needles was demonstrated by scanning electron microscopy. The observed mycelia were both intercellular and intracellular. The hyphal diameters varied significantly and striking swellings of unknown function were observed along internal hyphae. The observed needle colonization is discussed in connection with the spreading of fungal endophytes in the host tissues during the endophytic phase of L. piceae in Norway spruce needles.

Infection of roots of Norway spruce (Picea abies) by Heterobasidion annosum.

1987 ◽  
Vol 17 (4-5) ◽  
pp. 217-226 ◽  
Author(s):  
J. Stenlid ◽  
M. Johansson
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Heterobasidion Annosum

scholarly journals The Profitability of Cross-Cutting Practices in Butt-Rotten Picea abies Final-Felling Stands

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 874 ◽  
Author(s):  
Kärhä ◽  
Räsänen ◽  
Palander
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Processing Time ◽  
Wood Quality ◽  
Study Data ◽  
Heterobasidion Annosum ◽  
Time And Motion ◽  
The Cross ◽  
Motion Studies ◽  
The Impact

Research Highlights: This study offers new information on the cross cutting of decayed stems with the sounding of short (0.5 m) offcuts and the bucking of longer (3.0 m) butt-rotten poles. Background and Objectives: The root and butt-rot fungus Heterobasidion annosum sensu lato (Fr.) Bref. causes wood quality damage to trees in softwood forests. When timber is harvested in butt-rotten forests, it is essential that the decayed part of the tree is recognized and cut away from a stem, while the healthy and good quality log section of a stem is cross cut with precision sawlogs. The objective of the study was to investigate the impact of two off-cutting methods on stem processing time, cutting productivity, sawlog volume, and commercial value at the roadside landing when harvesting timber from the butt-rotten Norway spruce (Picea abies (L.) Karst.) final-felling forests. Materials and Methods: The length of the short offcuts used was 0.5 m. The results of the cross-cutting practices were compared to the decayed pulpwood poles of 3 m from the butt of the rotten stems. Time and motion studies were carried out in stands before the profitability calculations. The study data consisted of 1980 Norway spruce sawlog stems. Results: Sounding of the short offcuts added significantly to the stem processing time of butt-rotten stems, but the sawlog volume and the timber value recovery of the stems were higher than those of the decayed pulpwood poles of 3 m. Conclusions: The study concluded that sounding of butt-rotten Norway spruce stems with one to three offcuts is economically profitable if the diameter of the decayed column at the stem stump’s height is small (≤5 cm). In contrast, when the width of the decay is larger (>5 cm), it is more profitable to first cross cut the decayed pulpwood pole of 3 m and then to observe the height of the decayed part of the stem.

Spread of S and P group isolates of Heterobasidion annosum within and among Picea abies trees in central Lithuania

1998 ◽  
Vol 28 (7) ◽  
pp. 961-966 ◽  
Author(s):  
Rimvydas Vasiliauskas ◽  
Jan Stenlid
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Field Data ◽  
Heterobasidion Annosum ◽  
Related Difference ◽  
Spruce Wood

Spread of Heterobasidion annosum (Fr.) Bref. was investigated in a 60-year-old Norway spruce (Picea abies (L.) Karst.) stand in central Lithuania. Of the 375 trees sampled, H. annosum was isolated from 85 (22.7%). Forty nine (56.3%) of the isolates belonged to the S group and 38 (43.7%) to the P group. Among the S-group isolates, 35 genets occupied 49 trees (1.4 trees per genet on average). In the P group, 24 genets were detected in 37 trees (1.5 trees per genet on average). The largest S and P genets were 21 and 20 m in diameter, respectively. The S group spread was more extensive within stems than for the P group; mean length of the decay column for S-group isolates was 459 ± 159 cm (mean ± SD), and it was 327 ± 101 cm for P-group isolates (p = 0.0001). Average stump area affected by decay was 56 ± 15%for the S group, and 47 ± 16% for the P group (p = 0.016). This is the first published field data on intersterility group related difference in decay extension in tree stems. The S group is better adapted than the P group to growth in Norway spruce wood.

Infection of roots of Norway spruce (Picea abies) by Heterobasidion annosum.

1985 ◽  
Vol 15 (1) ◽  
pp. 32-45 ◽  
Author(s):  
M. Johansson ◽  
J. Stenlid
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Heterobasidion Annosum

Microfibrillar Orientation of the Innermost Surface of Conifer Tracheid Walls

IAWA Journal ◽  
1992 ◽  
Vol 13 (4) ◽  
pp. 411-417 ◽  
Author(s):  
Hisashi Abe ◽  
Jun Ohtani ◽  
Kazumi Fukazawa
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Picea Abies ◽  
Field Emission ◽  
Annual Ring ◽  
Larix Leptolepis ◽  
Conifer Species ◽  
Picea Jezoensis ◽  
Maximum Range ◽  
Scanning Electron

The orientation of the microfibri1s deposited on the innermost surfaces of the tracheid wall was observed in three conifer species, Larix leptolepis, Picea jezoensis, and Picea abies, using field emission scanning electron microscopy (FE-SEM). The microfibrillar orientation is different in each tracheid and exhibits either an S- or a Z-helix. The latest microfibrils deposited were normally joined into small bundles having various widths and had a different orientation from the microfibrils beneath them. When the latest deposited microfibrils on the innermost surface were oriented in an S-helix, the microfibrils beneath them were oriented in either a flatter S-helix or in a Z-helix, and when they were oriented in a Z-helix, the microfibrils beneath them were oriented in a steeper Z-helix. This is because, as seen from the lumen side, the microfibrillar orientation changes counterclockwise from the outer S23 to the innermost S3. These microfibrillar orientations varied throughout a single annual ring in each of the three species. The commonly observed angles of these microfibril were: Larix leptolepis: 70-80°, Picea jezoensis: 60-70°, and Picea abies: 40-50° in an S-helix, and the maximum range of angles was limited in extent to about 90 degrees in all species.

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