scholarly journals Root Rot of Black Spruce Caused by Cylindrocladium canadense in Eastern North America

Plant Disease ◽  
2005 ◽  
Vol 89 (2) ◽  
pp. 204-204 ◽  
Author(s):  
V. Vujanovic ◽  
M. St-Arnaud
Keyword(s):  
North America ◽  
Picea Mariana ◽  
Root Rot ◽  
Black Spruce ◽  
Potato Dextrose Agar ◽  
Eastern North America ◽  
Root Necrosis ◽  
Mother Plants ◽  
Germinating Seeds ◽  
Fungal Suspension

During October 2002, symptoms of root rot of black spruce, Picea mariana (Mill.) B.S.P., were observed in the St-Modeste (47°46′N, 69°36′W) conifer nursery (400 km northeast of Montreal, Quebec, Canada). Disease severity was low in the greenhouse-produced mother plants and 1-year-old seedlings and moderate in field-grown 2- and 3-year-old seedlings. A species of Cylindrocladium was isolated on potato dextrose agar from 12 symptomatic seedlings from the greenhouse and 12 from the field. The isolates produced chestnut-colored colonies and chlamydospores, both of which were typical of C. canadense Kang, Crous & Schoch (2). DNA was extracted from representative isolates (MTF 101, MTF 102), and the internal transcribed spacer (ITS) of the rDNA gene was amplified and sequenced (GenBank Accession Nos. AY705980 and AY705981). There was a 99% match with a sequence of C. canadense (GenBank Accession No. AF348256). However, there was approximately 10% divergence with the ITS sequence of C. floridanum (GenBank Accession No AF307343). MTF101 and MTF102 were pathogenic on black spruce seedlings when fungal suspension (106 CFU/ml) was added to germinating seeds in petri plates or infiltrated into roots of 2-week-old seedlings growing in sterilized, moist, sandy soil in the greenhouse. Within 3 weeks, inoculated seedlings exhibited typical root necrosis, while control seedlings were symptomless. C. canadense was reisolated only from symptomatic seedlings. The occurrence of C. canadense in eastern North America has significant implications for forestry regeneration. Previously, only C. floridanum had been reported as pathogenic in the St-Modeste nursery and in eastern North America(1). References: (1) R. C. Hamelin et al. Appl. Environ. Microbiol. 62:4026, 1996. (2) J. C. Kang et al. Syst. Appl. Microbiol. 24:206, 2001.

CO2 fluxes of a boreal black spruce chronosequence in eastern North America

2012 ◽  
Vol 153 ◽  
pp. 94-105 ◽  
Author(s):  
Jean-Lionel Payeur-Poirier ◽  
Carole Coursolle ◽  
Hank A. Margolis ◽  
Marc-André Giasson
Keyword(s):  
North America ◽  
Black Spruce ◽  
Eastern North America ◽  
Co2 Fluxes

Prolonged Absence of Disturbance Associated with Increased Environmental Stress May Lead to Reduced Seedbank Size in Picea mariana in Boreal Eastern North America

Ecosystems ◽  
2015 ◽  
Vol 18 (7) ◽  
pp. 1135-1150 ◽  
Author(s):  
Rik Van Bogaert ◽  
Sylvie Gauthier ◽  
Igor Drobyshev ◽  
Karelle Jayen ◽  
David F. Greene ◽  
...  
Keyword(s):  
North America ◽  
Environmental Stress ◽  
Picea Mariana ◽  
Eastern North America ◽  
Prolonged Absence

A late-glacial transition from Picea glauca to Picea mariana in southern New England

2007 ◽  
Vol 67 (3) ◽  
pp. 502-508 ◽  
Author(s):  
Matts Lindbladh ◽  
W. Wyatt Oswald ◽  
David R. Foster ◽  
Edward K. Faison ◽  
Juzhi Hou ◽  
...  
Keyword(s):  
North America ◽  
New England ◽  
Picea Mariana ◽  
Picea Glauca ◽  
Single Species ◽  
Late Glacial ◽  
Eastern North America ◽  
Southern New England ◽  
Edaphic Conditions ◽  
Ecological Changes

AbstractPicea is an important taxon in late-glacial pollen records from eastern North America, but little is known about which species of Picea were present. We apply a recently developed palynological method for discriminating the three Picea species in eastern North America to three records from New England. Picea glauca was dominant at ∼ 14,500–14,000 cal yr BP, followed by a transition to Picea mariana between ∼ 14,000 and 13,500 cal yr BP. Comparison of the pollen data with hydrogen isotope data shows clearly that this transition began before the beginning of the Younger Dryas Chronozone. The ecological changes of the late-glacial interval were not a simple oscillation in the position of a single species' range, but rather major changes in vegetation structure and composition occurring during an interval of variations in several environmental factors, including climate, edaphic conditions, and atmospheric CO2 levels.

scholarly journals Molecular Profiling of Rhizosphere Microbial Communities Associated with Healthy and Diseased Black Spruce (Picea mariana) Seedlings Grown in a Nursery

2004 ◽  
Vol 70 (6) ◽  
pp. 3541-3551 ◽  
Author(s):  
M. Filion ◽  
R. C. Hamelin ◽  
L. Bernier ◽  
M. St-Arnaud
Keyword(s):  
Picea Mariana ◽  
Root Rot ◽  
Black Spruce ◽  
Restriction Analysis ◽  
Phylogenetic Analyses ◽  
Methodological Approach ◽  
Rrna Gene ◽  
Wide Range ◽  
Bacteria And Fungi ◽  
Evenness Indices

ABSTRACT Bacterial and fungal populations associated with the rhizosphere of healthy black spruce (Picea mariana) seedlings and seedlings with symptoms of root rot were characterized by cloned rRNA gene sequence analysis. Triplicate bacterial and fungal rRNA gene libraries were constructed, and 600 clones were analyzed by amplified ribosomal DNA restriction analysis and grouped into operational taxonomical units (OTUs). A total of 84 different bacterial and 31 different fungal OTUs were obtained and sequenced. Phylogenetic analyses indicated that the different OTUs belonged to a wide range of bacterial and fungal taxa. For both groups, pairwise comparisons revealed that there was greater similarity between replicate libraries from each treatment than between libraries from different treatments. Significant differences between pooled triplicate samples from libraries of genes from healthy seedlings and pooled triplicate samples from libraries of genes from diseased seedlings were also obtained for both bacteria and fungi, clearly indicating that the rhizosphere-associated bacterial and fungal communities of healthy and diseased P. mariana seedlings were different. The communities associated with healthy and diseased seedlings also showed distinct ecological parameters as indicated by the calculated diversity, dominance, and evenness indices. Among the main differences observed at the community level, there was a higher proportion of Acidobacteria, Gammaproteobacteria, and Homobasidiomycetes clones associated with healthy seedlings, while the diseased-seedling rhizosphere harbored a higher proportion of Actinobacteria, Sordariomycetes, and environmental clones. The methodological approach described in this study appears promising for targeting potential rhizosphere-competent biological control agents against root rot diseases occurring in conifer nurseries.

scholarly journals Forest floor carbon exchange of a boreal black spruce forest in eastern North America

2009 ◽  
Vol 6 (9) ◽  
pp. 1849-1864 ◽  
Author(s):  
O. Bergeron ◽  
H. A. Margolis ◽  
C. Coursolle
Keyword(s):  
North America ◽  
Soil Temperature ◽  
Air Temperature ◽  
Forest Floor ◽  
Black Spruce ◽  
Ecosystem Respiration ◽  
Light Availability ◽  
Ground Cover ◽  
Eastern North America ◽  
Spruce Forest

Abstract. This study reports continuous automated measurements of forest floor carbon (C) exchange over feathermoss, lichen, and sphagnum micro-sites in a black spruce forest in eastern North America during snow-free periods over three years. The response of soil respiration (Rs-auto) and forest floor photosynthesis (Pff) to environmental factors was determined. The seasonal contributions of scaled up Rs-auto adjusted for spatial representativeness (Rs-adj) and Pff (Pff-eco) relative to that of total ecosystem respiration (Re) and photosynthesis (Peco), respectively, were also quantified. Shallow (5 cm) soil temperature explained 67–86% of the variation in Rs-auto for all ground cover types, while deeper (50 and 100 cm) soil temperatures were related to Rs-auto only for the feathermoss micro-sites. Base respiration was consistently lower under feathermoss, intermediate under sphagnum, and higher under lichen during all three years. The Rs-adj/Re ratio increased from spring through autumn and ranged from 0.85 to 0.87 annually for the snow-free period. The Rs-adj/Re ratio was negatively correlated with the difference between air and shallow soil temperature and this correlation was more pronounced in autumn than summer and spring. Maximum photosynthetic capacity of the forest floor (Pff-max) saturated at low irradiance levels (~200 μmol m−2 s−1) and decreased with increasing air temperature and vapor pressure deficit for all three ground cover types, suggesting that Pff was more limited by desiccation than by light availability. Pff-max was lowest for sphagnum, intermediate for feathermoss, and highest for lichen for two of the three years. Pff normalized for light peaked at air temperatures of 5–8°C, suggesting that this is the optimal temperature range for Pff. The Pff-eco/Peco ratio varied from 13 to 24% over the snow-free period and reached a minimum in mid-summer when both air temperature and Peco were at their maximum. On an annual basis, Pff-eco accounted for 17–18% of Peco depending on the year and the snow-free season totals of Pff-eco were 23–24% that of Rs-adj.

Protection of black spruce seedlings against Cylindrocladium root rot with ectomycorrhizal fungi

1999 ◽  
Vol 77 (1) ◽  
pp. 169-174 ◽  
Author(s):  
Chantal Morin ◽  
Julie Samson ◽  
Michel Dessureault
Keyword(s):  
Ectomycorrhizal Fungi ◽  
Picea Mariana ◽  
Root Rot ◽  
Black Spruce ◽  
Inhibitory Effect ◽  
Paxillus Involutus ◽  
Hebeloma Cylindrosporum ◽  
Cylindrocladium Floridanum ◽  
Forest Nurseries

Cylindrocladium floridanum Sobers and Seymour, principal causal agent of root rot of conifers in forest nurseries, was grown in vitro with four species of ectomycorrhizal fungi, Paxillus involutus, Hebeloma cylindrosporum, Laccaria bicolor, and Tricholoma sp. The effect of inoculating black spruce seedlings (Picea mariana (Mill.) B.S.P.) with P. involutus was also investigated. Tricholoma sp. and especially P. involutus and H. cylindrosporum inhibited growth of C. floridanum in Petri dishes, while L. bicolor was inhibited and completely covered by C. floridanum. Hyphae of the pathogen in the contact zone were deteriorated in the presence of P. involutus and H. cylindrosporum. The inoculation of P. involutus reduced the number of infected black spruce seedlings by approximately 50%. However, the simultaneous inoculation of two different strains of P. involutus did not significantly reduce disease development. Linear regression demonstrated that the percentage of infected plants was negatively correlated with mycorrhiza formation. The relation between these two variables also showed that even if colonization by P. involutus is poor or null, it has some inhibitory effect against Cylindrocladium root rot.Key words: Paxillus involutus, Cylindrocladium floridanum, root rot, ectomycorrhizal fungi, biological control, Picea mariana.

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