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.

Survey and ecological aspects of presumed ectomycorrhizal fungi associated with black spruce in northern Minnesota

1990 ◽  
Vol 68 (4) ◽  
pp. 825-831 ◽  
Author(s):  
Robert L. Doudrick ◽  
Elwin L. Stewart ◽  
Alvin A. Alm
Keyword(s):  
Ectomycorrhizal Fungi ◽  
Picea Mariana ◽  
Selection Criteria ◽  
Black Spruce ◽  
Laccaria Bicolor ◽  
Site Preference ◽  
Geologic History ◽  
Aseptic Culture ◽  
Ecological Aspects ◽  
Spruce Stands

Twenty-two stands of black spruce, Picea mariana (Mill.) B.S.P., in northern Minnesota were surveyed for ectomycorrhizal fungi. Site selection criteria in black spruce stands included geologic history, soil type, stand origin, age, and productivity. Site preference relationships were noted for several of the 46 species of fungi collected during the 2-year study. Twenty-five isolates were tested in aseptic culture for their ability to form ectomycorrhizae with black spruce seedlings. Ectomycorrhizae were produced by Cenococcum sp., Laccaria bicolor (Maire) Orton, Laccaria laccata var. moelleri Singer, Rhizopogon sp., and Suillus cavipes (Opat.) Smith & Thiers.

scholarly journals Changes in the Density and Composition of Rhizosphere Pathogenic Fusarium and Beneficial Trichoderma Contributing to Reduced Root Rot of Intercropped Soybean

2021 ◽  
Author(s):  
Xiaoli Chang ◽  
Huiting Xu ◽  
Li Yan ◽  
Dan Zhu ◽  
Wei Wang ◽  
...  
Keyword(s):  
Root Rot ◽  
Cell Walls ◽  
Rhizosphere Soil ◽  
Fusarium Species ◽  
Inhibitory Effect ◽  
Trichoderma Species ◽  
Soybean Root ◽  
The Difference ◽  
Rhizosphere Microbial Community

Abstract BackgroundThe dynamic of soil-borne disease is closely related to the rhizosphere microbial communities. Maize-soybean intercropping can suppress soybean root rot as compared to monoculture. However, it is still unknown whether rhizosphere microbial community participates in the regulation of intercropped soybean root rot.MethodsIn this study, the difference of rhizosphere Fusarium and Trichoderma community was compared between healthy or root-rotted soybean rhizosphere soil from soybean monoculture and maize-soybean intercropping, and the inhibitory effect of potential biocontrol Trichoderma against pathogenic Fusarium were examined.ResultsThe abundance of rhizosphere Fusarium was remarkably different between intercropping and monoculture, while Trichoderma was largely accumulated in healthy rhizosphere soil of intercropping rather than monoculture. Four rhizosphere Fusarium species identified were all pathogenic to soybean but displayed distinct composition and isolation proportion in the corresponding soil types. As the dominant and most aggressive species, F. oxysporum was more frequently isolated in diseased soil of monoculture. Furthermore, of three Trichoderma species identified, T. harzianum dramatically increased in the rhizosphere of intercropping rather than monoculture as compared to T. virens and T. afroharzianum. For in-vitro antagonism test, Trichoderma strains had antagonistic effects on F. oxysporum with the percentage of mycelial inhibition ranging of 50.59%-92.94%, and they displayed good mycoparasitic abilities against F. oxysporum through coiling around and entering into the hyphae, expanding along cell-cell lumen and even dissolving cell walls of target fungus.ConclusionThese results indicate maize-soybean intercropping significantly increase the density and composition proportion of beneficial Trichoderma to antagonist the pathogenic Fusarium species, thus contributing to the suppression of soybean root rot under intercropping.

Somatic embryo maturation, germination, and soil establishment of plants of black and white spruce (Picea mariana and Picea glauca)

1990 ◽  
Vol 68 (12) ◽  
pp. 2583-2589 ◽  
Author(s):  
S. M. Attree ◽  
T. E. Tautorus ◽  
D. I. Dunstan ◽  
L. C. Fowke
Keyword(s):  
Abscisic Acid ◽  
Somatic Embryo ◽  
Picea Mariana ◽  
Picea Glauca ◽  
Black Spruce ◽  
White Spruce ◽  
Embryo Maturation ◽  
Black And White ◽  
Somatic Embryo Maturation

Somatic embryo maturation, germination, and soil establishment frequencies were compared for two conifer species, white and black spruce (Picea glauca and Picea mariana). The comparison of the two species regenerated and established in soil under the same conditions showed black spruce to be the most responsive. Shorter exposure times to 32 μM abscisic acid were not as effective as maturation on a medium containing 16 μM abscisic acid for 28 days. This gave similar maturation frequencies for the two species (6–8%), and germination frequencies of 64% for white spruce and over 73% for black spruce. Over 1800 black and white spruce plantlets were recovered, and more than 400 were transferred from in vitro to nonsterile conditions. Sixty percent (160) of the black spruce plantlets survived transfer and continued to grow vigorously. By comparison only 18% (29) of the white spruce plantlets survived, and half of these rapidly produced dormant buds and underwent no further shoot growth. White spruce plants that did not produce dormant buds grew vigorously. These results indicate that there are large differences in the ability of these closely related species to respond to plantlet establishment following regeneration from somatic embryos, and that black spruce is highly responsive to micropropagation by this method. Key words: Picea glauca, Picea mariana, somatic embryogenesis, maturation, germination, soil establishment.

Differential effect of chitosan on root rot fungal pathogens in forest nurseries

2000 ◽  
Vol 77 (10) ◽  
pp. 1460-1468 ◽  
Author(s):  
Philippe Laflamme ◽  
Nicole Benhamou ◽  
Guy Bussières ◽  
Michel Dessureault
Keyword(s):  
Root Rot ◽  
Fungal Pathogens ◽  
Wall Thickening ◽  
Growth Morphology ◽  
Morphological Alterations ◽  
Fusarium Acuminatum ◽  
Transmission Electron ◽  
Forest Nurseries ◽  
Membrane Cell

The effect of chitosan on the growth, morphology, and ultrastructure of Cylindrocladium floridanum Sobers & Seymour, Cylindrocarpon destructans (Zinss.) Scholten, Fusarium acuminatum Ellis & Everh., and Fusarium oxysporum Schlecht. was investigated in vitro. Chitosan was found to reduce the radial growth of all the fungi studied with some differences. Light microscope observations showed that chitosan induced morphological alterations to all fungi. Transmission electron microscope investigations revealed ultrastructural alterations such as increased vacuolation, retraction, and alteration of the plasma membrane, cell wall thickening, hyphal distortion, and cytoplasm aggregation. The possible modes of action of chitosan are discussed.

Application of ectomycorrhizal fungi in rooting of Scots pine fascicular shoots

2000 ◽  
Vol 30 (8) ◽  
pp. 1221-1230 ◽  
Author(s):  
Karoliina Niemi ◽  
Maija Salonen ◽  
Arild Ernstsen ◽  
Helvi Heinonen-Tanski ◽  
Hely Häggman
Keyword(s):  
Scots Pine ◽  
Ectomycorrhizal Fungi ◽  
Production Capacity ◽  
Pisolithus Tinctorius ◽  
Paxillus Involutus ◽  
Root Induction ◽  
In Vitro Production ◽  
Vitro Production

The ectomycorrhizal fungi, Pisolithus tinctorius (Pers.) Coker & Couch and three Paxillus involutus (Batsch) Fr. strains, were used to enhance in vivo rooting in fascicular shoots of 49 Scots pine (Pinus sylvestris L.) genotypes representing seed families from southern and northern Finland. Inoculation with specific fungi either increased the rooting percentage or accelerated root formation expressed as an increased number of adventitious roots per cutting. Only one of the six seed families gave no positive response. The relationship between the in vitro production of free and conjugated forms of indole-3-acetic acid (IAA) by the fungi and rooting was also investigated. Pisolithus tinctorius was the only significant producer of IAA in the absence of exogenous tryptophan. All the Paxillus involutus strains also synthesized both free and conjugated IAA but did that actively only from exogenous tryptophan. In vitro production of IAA did not correlate with root induction in vivo, but the rooting responses depended on the fungus strains and the Scots pine seed families and (or) genotypes within families. This indicates that in vitro IAA production capacity cannot be the only criterion when selecting ectomycorrhizal fungi for rooting in vivo and that specific genotype-genotype interactions play a key role in root initiation.

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 The effect of fungicides used in the protection of forest tree seedlings on the growth of ectomycorrhizal fungi

2014 ◽  
Vol 32 (2) ◽  
pp. 315-322 ◽  
Author(s):  
Marta Aleksandrowicz-Trzcińska ◽  
Andrzej Grzywacz
Keyword(s):  
Ectomycorrhizal Fungi ◽  
Screening Method ◽  
Forest Tree ◽  
Tree Seedlings ◽  
Laccaria Laccata ◽  
Suillus Luteus ◽  
Study Results ◽  
Forest Nurseries ◽  
Selection Of

Fungitoxical activity of ten fungictdes most commonly used in the phytopathological protection of forest nurseries was studied, using the <i>in vitro</i> screening method. The fungitoxical activity was studied against five species of ectomycorrhizal fungi (seven strains). The resulting growth inhibition of fungi species and strains tested was prcscnted in terms of fungitoxicity classes of the preparations used. The highest total fungitoxicity against the mycelia of fungi taxa tested was found for Euparen, Bravo, Dithane M-45 and Ridomil. The weakest fungitoxical effect was observed for Topsin M and Bayleton. The least susceptible for the action of the fungicides studied were mycelia of <i>Suillus luteus</i>, while the most susceptible were those of <i>Hebeloma crustuliniforme</i> and <i>Laccaria laccata</i>. The study results arę useful for the selection of fungi strains proper for the artificial mycorrhization of seedlings.

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.

scholarly journals COMPARATIVE ASSESSMENT OF FUNGICIDAL ACTIVITY OF PREPARATIONS FOR PRESOWING TREATMENT OF WINTER WHEAT

2021 ◽  
Vol 4 (28) ◽  
pp. 149-158
Author(s):  
N.M. Sidorov ◽  
◽  
E.A. Gyrnets ◽  
M.M. Astakhov ◽  
K.Yu. Saenko ◽  
...  
Keyword(s):  
Root Rot ◽  
Seed Treatment ◽  
Fungal Pathogens ◽  
Fungicidal Activity ◽  
Plant Protection ◽  
Aerial Mycelium ◽  
Plant Protection Products ◽  
Inhibitory Effect ◽  
Wide Range

The massive use of one-component fungicides has caused the problem of the emergence of resistant forms of phytopathogens. The development of multicomponent plant protection products is one of the ways of dealing with such a situation. The aim of the study is to determine the effectiveness of multicomponent chemical dressing agents in suppressing the most common fungal pathogens and seed infections in vitro. This work was performed in 2020 in the Federal Research Center for Biological Plant Protection (Krasnodar) in the laboratory of the creation of microbiological plant protection products and a collection of microorganisms. Fungi of the Fusarium, Microdochium, Bipolaris, Alternaria, Penicillium, Rhizoctonia, Septoria, Pyrenophora genera were used as test objects. The fungicidal activity of chemical preparations against economically significant phytopathogens causing root rot was evaluated in laboratory conditions by the method of serial dilutions followed by sowing on a nutrient medium. In addition, the effectiveness of the preparations was investigated by the method of treated seeds phytoexamination according to GOST 12044–93. The preparations, which included triazoles and phenylpyrroles, had the strongest inhibitory effect (100 %) on pathogens of Rhizoctonia, helminthosporiosis and septoria. The preparation containing compounds of the group of triazoles and strobilurins suppressed the growth of Rhizoctonia solani only. The preparations’ inhibitory effect on a number of phytopathogenic fungi was manifested in growth retardation, absence of aerial mycelium development and mycelium pigmentation. Concerning the causative agents of Fusarium root rot, the two-component preparations efficacy ranged from 51 % to 74.4 %; three-component one – from 42.9 % to 84.7 % depending on the species of the genus Fusarium. Presowing seed treatment made it possible to inhibit the growth of fungi of the genera Fusarium, Mucor, Aspergillus; significantly inhibit the development of the fungus Alternaria (spread in the experimental variant – 1.7 %, in the control variant – 46.7 %). From the data obtained, it can be concluded that multicomponent preparations based on triazoles and phenylpyrroles are highly effective in suppressing a wide range of phytopathogens and can be recommended for presowing seed treatment.

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