Opportunistically Pathogenic Root Rot Fungi: Armillaria Species

A survey to identify Armillaria root rot pathogens, their host range, and geographic distribution was conducted in the Canadian prairie provinces. Collections of basidiocarps and isolates from the wood of gymptomatic or dead trees were made. Armillaria species were identified by interfertility testing and by the L-DOPA method. Three Armillaria species, A. ostoyae (Romagn.) Herink, A. sinapina Bérubé & Dessureault, and A. calvescens Bérubé & Dessureault, were identified. Armillariaostoyae was the most common species in both the subalpine and boreal forests and was found on a wide variety of coniferous and deciduous host species. Armillariasinapina was in both the boreal and subalpine forests but occurred primarily on deciduous host species. Armillariacalvescens was rare and was found only in the boreal forest on both coniferous and deciduous host species.

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Virulence and Stump Colonization Ability of Armillaria borealis on Norway Spruce Seedlings in Comparison to Sympatric Armillaria Species

Plant Disease ◽

10.1094/pdis-06-16-0933-re ◽

2017 ◽

Vol 101 (3) ◽

pp. 470-479 ◽

Cited By ~ 4

Author(s):

Renate Heinzelmann ◽

Simone Prospero ◽

Daniel Rigling

Keyword(s):

Norway Spruce ◽

Root Rot ◽

Mixed Forest ◽

Tree Age ◽

Northern Europe ◽

Seedling Mortality ◽

Pathogenic Potential ◽

Colonization Ability ◽

Armillaria Species ◽

Stem Segments

Although Armillaria borealis is one of the closest relatives of the aggressive root rot pathogen A. ostoyae, little is known about its ecology. In central and northern Europe, A. borealis often co-occurs with A. ostoyae or A. cepistipes, a weak pathogen, in conifer or mixed-forest stands. In this study, the virulence of 10 A. borealis, nine A. ostoyae, and five A. cepistipes isolates toward 2- and 4-year-old potted Norway spruce (Picea abies) seedlings was assessed. In addition, the ability of all isolates to colonize fresh stumps cut from 6-year-old Norway spruce seedlings was tested. All inoculations were done by insertion of Armillaria-colonized hazelnut stem segments into the soil substrate. On the 2-year-old seedlings, A. borealis and A. ostoyae showed, overall, a similar virulence 29 months after inoculation whereas, on the 4-year-old seedlings, A. ostoyae was more virulent. The third species in the experiment, A. cepistipes, caused almost no seedling mortality. Six months after cutting, the highest percentage of stumps was colonized by A. ostoyae (94.3%), followed by A. borealis (85.2%), and A. cepistipes (78.4%). Our inoculation experiments show that A. borealis has a clear pathogenic potential toward Norway spruce seedlings. However, compared with A. ostoyae, damage caused by A. borealis may decrease more rapidly with increasing tree age. Similar to other Armillaria species, A. borealis seems to be an efficient colonizer of fresh stumps.

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Early development of root rot in young Norway spruce planted on sites infected by Heterobasidion in southern Finland

Canadian Journal of Forest Research ◽

10.1139/x02-200 ◽

2003 ◽

Vol 33 (4) ◽

pp. 604-611 ◽

Cited By ~ 26

Author(s):

Tuula Piri

Keyword(s):

Picea Abies ◽

Norway Spruce ◽

Root Rot ◽

Heterobasidion Annosum ◽

Tree Stand ◽

Clear Cutting ◽

Plantation Age ◽

Armillaria Cepistipes ◽

Experimental Plots ◽

Armillaria Species

Root rot infections in Norway spruce (Picea abies (L.) Karst.) regeneration, planted after the clear-cutting of spruce on sites infested by Heterobasidion, were investigated on 21 experimental plots in eight 2- to 23-year-old plantations. Heterobasidion root rot became evident about 10 years after planting and the proportion of infected spruces increased steadily with plantation age. The average number of planted spruces infected per old decayed stump was 0.2 trees in 2- to 9-year-old plantations, 0.8 trees in 11- to 15-year-old plantations, and 1.8 trees in 20- to 23-year-old plantations. About 10 and 20 years after planting, 7 and 23% of the planted spruces in the disease centers were infected by Heterobasidion. Heterobasidion parviporum Niemelä & Korhonen, and Heterobasidion annosum (Fr.) Bref. s. str. caused 98 and 2% of the Heterobasidion infections in the previous spruce rotation, and 96 and 4% in the spruce regeneration, respectively. In all, 71% of the infected regeneration trees were attacked by a Heterobasidion genet that was also isolated from the stumps of the previous tree stand. Armillaria species (Armillaria borealis Marxmüller & Korhonen and Armillaria cepistipes Velenovský) were isolated from 7% of the planted spruces.

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Associations Between Armillaria Species and Host Plants in U.K. Gardens

Plant Disease ◽

10.1094/pdis-04-17-0472-re ◽

2017 ◽

Vol 101 (11) ◽

pp. 1903-1909 ◽

Cited By ~ 6

Author(s):

Jassy Drakulic ◽

Caroline Gorton ◽

Ana Perez-Sierra ◽

Gerard Clover ◽

Liz Beal

Keyword(s):

Host Plant ◽

Plant Diversity ◽

Root Rot ◽

Host Plants ◽

Specific Pcr ◽

Royal Horticultural Society ◽

Pcr Rflp ◽

Species Specific ◽

Armillaria Species

Honey fungus (Armillaria spp.) root rot is the disease most frequently inquired about by U.K. gardeners to the Royal Horticultural Society. Armillaria epidemiology has been studied within forestry and agriculture, but data are lacking within gardens, which have greater host plant diversity than orchards and vineyards and greater disturbance than woodlands. Which Armillaria species are responsible for garden disease, and how the broad range of susceptible ornamentals are differentially affected is not known. To address this, isolates of Armillaria were obtained from dead and dying plants from across the U.K. over a 4-year period (2004 to 2007). Species were identified by PCR-RFLP for IGS, and further verified by species-specific PCR for EF-1 α. Of the seven species known in the U.K., three were identified: A. mellea (83.1%), A. gallica (15.8%), and A. ostoyae (1.1%). Armillaria was isolated from trees, shrubs, and nonwoody plants including bulbs and vegetables, with newly recorded hosts listed herein. A. mellea was associated with infections of multiple hosts, and with all infections of the most common host, Ligustrum. In sites where more than one Armillaria species was found, the combination was of A. mellea and A. gallica, raising questions regarding the interactions of these species in U.K. gardens.

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Varietal Differences of the Rice Plant in Relation to the Resisting Capacity to Root-rot Disease, induced by Hydrogen Sulphide, and a Convenient Method to test Them,

Japanese Journal of Crop Science ◽

10.1626/jcs.23.167 ◽

1955 ◽

Vol 23 (3) ◽

pp. 167-168 ◽

Cited By ~ 2

Author(s):

Isamu BABA

Keyword(s):

Hydrogen Sulphide ◽

Convenient Method ◽

Root Rot ◽

Rice Plant ◽

Varietal Differences ◽

Root Rot Disease ◽

Rot Disease

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Infections of bean plant and field soil are linked to region, root rot pathogen, and agro-ecosystem

Hellenic Plant Protection Journal ◽

10.2478/hppj-2021-0002 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

B. Naseri ◽

M. Gheitury ◽

M. Veisi

Keyword(s):

Root Rot ◽

Multivariate Analyses ◽

Control Method ◽

Control Strategies ◽

Fusarium Species ◽

Macrophomina Phaseolina ◽

Soil Variables ◽

Plant Infection ◽

Pathogen Prevalence ◽

Soil Infestation

SummaryUnderstanding pathogen-agrosystem interaction is particularly essential when applying a control method to minimize pathogen prevalence prior to plant infection. To meet this requirement, frequency of major root rot pathogens isolated from bean root and seed, and their soil populations were examined in farmers’ fields. Multivariate analyses evidenced more frequent isolations of Fusarium solani and Rhizoctonia solani from root and seed compared to Macrophomina phaseolina and Fusarium oxysporum. Two Fusarium species had denser soil populations than R. solani and M. phaseolina. More frequent isolations of pathogens were detected in root and seed collected from Abhar and Khodabandeh compared to Kheirabad region. Agronomic and soil variables corresponded less closely to root infections compared to soil infestation and seed infections. Bean market class, herbicide application, and planting depth were linked to root, seed and soil infestations. Such information provides a basis for increased confidence in choosing appropriate control strategies for a pathogen and region in sustainable agriculture.

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'Shinano Hope', a Fusarium Root Rot-Resistant Lettuce

Engei Gakkai zasshi ◽

10.2503/jjshs.73.429 ◽

2004 ◽

Vol 73 (5) ◽

pp. 429-434 ◽

Cited By ~ 7

Author(s):

Nobuaki Tsuchiya ◽

Kiyoshi Yoshida ◽

Tomita Usui ◽

Motohisa Tsukada

Keyword(s):

Root Rot ◽

Fusarium Root Rot

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Managemental efficiency of the use of fungicides in abatement against soybeans disease

сборник статей всероссийской научной конференции с международным участием "Растениеводство и луговодство" ◽

10.26897/978-5-9675-1762-4-2020-109 ◽

2020 ◽

Author(s):

G.A. Polovinkin ◽

◽

I.L. Tychinskaya

Keyword(s):

Root Rot ◽

Wide Spread ◽

Protective Measures ◽

Biological Effectiveness

As a result of the studies carried out, a complex of diseases on soybeans was identified: ascochitis, peronoscrosis and root rot. The studies carried out indicate a wide spread of diseases in the studied culture and the need to develop a set of protective measures to combat them. The greatest biological effectiveness was selected in the variant when using a complex of fungicides Redigo Pro + Prozaro, which averaged 93.7% for diseases.

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