Microbiological differences between soils suppressive and conducive of the saprophytic growth of Gaeumannomyces graminis var. tritici

1988 ◽  
Vol 34 (7) ◽  
pp. 860-864 ◽  
Author(s):  
A. Simon ◽  
K. Sivasithamparam
Keyword(s):  
Microbial Respiration ◽  
Gaeumannomyces Graminis ◽  
Trichoderma Spp ◽  
Suppressive Soil ◽  
Soil Microbial ◽  
Soil Pathogen ◽  
Pathogen Suppression ◽  
Gram Negative Organisms ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Annual Application

A soil acidified by ammonium sulphate following annual application of the fertilizer for 9 years was suppressive of the saprophytic growth of Gaeumannomyces graminis var. tritici in soil (pathogen suppressive). The same soil amended with lime was pathogen conducive. In natural field soil microbial respiration and the 'total' number of aerobic microorganisms were greater in the conducive than in the suppressive soil. In a soil-sandwich bioassay of the transferable suppression of saprophytic growth of the pathogen there were higher numbers of 'total' aerobic microorganisms, fluorescent pseudomonads, and Gram-negative organisms, but lower numbers of filamentous fungi and yeasts in the conducive than in the suppressive soil. It was estimated that Trichoderma spp. made up 71 and 34% of the total numbers of fungi counted in the suppressive and conducive soils, respectively. It is proposed that Trichoderma spp. played a major role in the transferable pathogen suppression in the suppressive soil.

The soil environment and the suppression of saprophytic growth of Gaeumannomyces graminis var. tritici

1988 ◽  
Vol 34 (7) ◽  
pp. 865-870 ◽  
Author(s):  
A. Simon ◽  
K. Sivasithamparam
Keyword(s):  
Gaeumannomyces Graminis ◽  
Soil Environment ◽  
Single Application ◽  
Trichoderma Spp ◽  
Γ Radiation ◽  
Soil Pathogen ◽  
Pathogen Suppression ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Limed Soil ◽  
Conducive Soil

The effect of the soil environment on the transferable suppression of the saprophytic growth of Gaeumannomyces graminis var. tritici (pathogen suppression) was studied in a field soil acidified to pH 4.3 by annual treatment with ammonium sulphate for 9 years and in the same soil further amended with a single application of lime (pH 5.4). Pathogen suppression and the activity of Trichoderma spp. were greater when (i) the unlimed (pathogen-suppressive) soil was added at a rate of 1% (w/w) to the same soil treated with γ-radiation than when added at the same rate to the irradiated limed soil; (ii) the limed (pathogen-conducive) soil was added at 1% (w/w) to the irradiated unlimed soil than when added at the same rate to the irradiated limed soil. Pathogen suppression and the activity of Trichoderma spp. were increased in both soils with the addition of an antibacterial agent. The saprophytic growth of G. graminis var. tritici was reduced in the unsterile pathogen-suppressive but not in the pathogen-conducive soil, following the addition of inoculum of T. koningii. It is proposed that both the abiotic and biotic environments of soil can influence the expression of transferable pathogen suppression which, in the soils tested, is related to the activity of Trichoderma spp.

scholarly journals In vitro Antagonistic Mechanisms of Trichoderma spp. and Talaromyces flavus to Control Gaeumannomyces graminis var. tritici the Causal Agent of Wheat Take-all Disease

2015 ◽  
Vol 3 (8) ◽  
pp. 629
Author(s):  
Seddighe Mohammadi ◽  
Leila Ghanbari
Keyword(s):  
Pathogenic Fungus ◽  
Causal Agent ◽  
Gaeumannomyces Graminis ◽  
Dual Culture ◽  
Mycelium Growth ◽  
Trichoderma Spp ◽  
Talaromyces Flavus ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

Wheat take-all disease caused by Gaeumannomyces graminis var. tritici has recently been detected in different regions of Iran. With respect to biocontrol effect of Trichoderma spp. on many pathogenic fungi, seven isolates of Trichoderma and four isolates of Talaromyces were in vitro evaluated in terms of their biological control against the disease causal agent. In dual culture test the five isolates showed efficient competition for colonization against pathogenic fungus and the highest percentages of inhibition belonging to Talaromyces flavus 60 and Talaromyces flavus 136 were 59.52 and 57.61%, respectively. Microscopic investigations showed that in regions where antagonistic isolates and Gaeumannomyces graminis var. tritici coincide, hyphal contact, penetration and fragmentation of Gaeumannomyces graminis var. tritici were observed. Investigating the effect of volatile and non-volatile compounds at 10 ml concentration showed that the highest inhibition percentage on mycelium growth of the pathogen caused by T. harzianum (44.76%) and T. longibrachiatum (52.38%) respectively.

Interactions among Gaeumannomyces graminis var. tritici, Trichoderma koningii, and soil bacteria

1988 ◽  
Vol 34 (7) ◽  
pp. 871-876 ◽  
Author(s):  
A. Simon ◽  
K. Sivasithamparam
Keyword(s):  
Pure Culture ◽  
Soil Bacteria ◽  
Gaeumannomyces Graminis ◽  
Suppressive Soil ◽  
Trichoderma Koningii ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Conducive Soil

Interactions among Gaeumannomyces graminis var. tritici, Trichoderma koningii, and soil bacteria were studied in vitro and in soils suppressive and conducive of the saprophytic growth of G. graminis var. tritici. Fifty-four percent of bacteria isolated from the suppressive soil and 10% from the conducive soil were antagonistic to G. graminis var. tritici in vitro. The reduction in the growth of T. koningii in vitro by metabolite(s) produced in pure culture by soil bacteria was 14 and 28% for the bacteria isolated from the suppressive and conducive soil, respectively. Metabolite(s) produced by T. koningii in pure culture inhibited the growth in vitro of 8 and 65% of the bacteria isolated from the suppressive and conducive soils, respectively. All isolates of Trichoderma tested produced metabolite(s) that inhibited growth of G. graminis var. tritici in pure culture. The metabolite(s) produced by one isolate of T. koningii inhibited growth of all isolates of Trichoderma in vitro. Trichoderma koningii suppressed saprophytic growth of G. graminis var. tritici in irradiated conducive soil in the absence but not in the presence of bacteria isolated from the same soil. The results suggest that the suppressive soil may be more suppressive of the saprophytic growth of G. graminis var. tritici and less suppressive of the growth of T. koningii than the conducive soil.

scholarly journals Historical climate controls soil respiration responses to current soil moisture

2017 ◽  
Vol 114 (24) ◽  
pp. 6322-6327 ◽  
Author(s):  
Christine V. Hawkes ◽  
Bonnie G. Waring ◽  
Jennifer D. Rocca ◽  
Stephanie N. Kivlin
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Soil Respiration ◽  
Carbon Cycling ◽  
Large Scale ◽  
Microbial Respiration ◽  
Rainfall Gradient ◽  
Soil Microbial ◽  
Historical Climate ◽  
Moisture Dependence

Ecosystem carbon losses from soil microbial respiration are a key component of global carbon cycling, resulting in the transfer of 40–70 Pg carbon from soil to the atmosphere each year. Because these microbial processes can feed back to climate change, understanding respiration responses to environmental factors is necessary for improved projections. We focus on respiration responses to soil moisture, which remain unresolved in ecosystem models. A common assumption of large-scale models is that soil microorganisms respond to moisture in the same way, regardless of location or climate. Here, we show that soil respiration is constrained by historical climate. We find that historical rainfall controls both the moisture dependence and sensitivity of respiration. Moisture sensitivity, defined as the slope of respiration vs. moisture, increased fourfold across a 480-mm rainfall gradient, resulting in twofold greater carbon loss on average in historically wetter soils compared with historically drier soils. The respiration–moisture relationship was resistant to environmental change in field common gardens and field rainfall manipulations, supporting a persistent effect of historical climate on microbial respiration. Based on these results, predicting future carbon cycling with climate change will require an understanding of the spatial variation and temporal lags in microbial responses created by historical rainfall.

scholarly journals Detection of Gaeumannomyces Graminis Var. Tritici in Wheat Stubble

1973 ◽  
Vol 26 (6) ◽  
pp. 1285 ◽  
Author(s):  
GC Mac Nish
Keyword(s):  
Visual Assessment ◽  
The Other ◽  
Gaeumannomyces Graminis ◽  
Other Hand ◽  
Wheat Stubble ◽  
Gaeumannomyces Graminis Var Tritici

Two methods (visual assessment and a bioassay) of detecting the presence of G. graminis var. tritici in wheat stubble were compared. Of the stubble visually assessed as infected, only 4 % was not confirmed as infected by the bioassay. On the other hand, the bioassay showed that 41 % of the stubble visually assessed as free of infection was incorrectly assigned.

scholarly journals Isolation, Characterization, and Sensitivity to 2,4-Diacetylphloroglucinol of Isolates of Phialophora spp. from Washington Wheat Fields

2010 ◽  
Vol 100 (5) ◽  
pp. 404-414 ◽  
Author(s):  
Youn-Sig Kwak ◽  
Peter A. H. M. Bakker ◽  
Debora C. M. Glandorf ◽  
Jennifer T. Rice ◽  
Timothy C. Paulitz ◽  
...  
Keyword(s):  
Sequence Comparison ◽  
Phylogenetic Trees ◽  
Washington State ◽  
Gaeumannomyces Graminis ◽  
Wild Oat ◽  
Genetic Characteristics ◽  
Oat Cultivars ◽  
Eastern Washington ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

Dark pigmented fungi of the Gaeumannomyces–Phialophora complex were isolated from the roots of wheat grown in fields in eastern Washington State. These fungi were identified as Phialophora spp. on the basis of morphological and genetic characteristics. The isolates produced lobed hyphopodia on wheat coleoptiles, phialides, and hyaline phialospores. Sequence comparison of internal transcribed spacer regions indicated that the Phialophora isolates were clearly separated from other Gaeumannomyces spp. Primers AV1 and AV3 amplified 1.3-kb portions of an avenacinase-like gene in the Phialophora isolates. Phylogenetic trees of the avenacinase-like gene in the Phialophora spp. also clearly separated them from other Gaeumannomyces spp. The Phialophora isolates were moderately virulent on wheat and barley and produced confined black lesions on the roots of wild oat and two oat cultivars. Among isolates tested for their sensitivity to 2,4-diacetylphloroglucinol (2,4-DAPG), the 90% effective dose values were 11.9 to 48.2 μg ml–1. A representative Phialophora isolate reduced the severity of take-all on wheat caused by two different isolates of Gaeumannomyces graminis var. tritici. To our knowledge, this study provides the first report of an avenacinase-like gene in Phialophora spp. and demonstrated that the fungus is significantly less sensitive to 2,4-DAPG than G. graminis var. tritici.

Gaeumannomyces graminis var. tritici. [Descriptions of Fungi and Bacteria].

1973 ◽  
Author(s):  
J. Walker
Keyword(s):  
Geographical Distribution ◽  
Root Hairs ◽  
Seed Transmission ◽  
Gaeumannomyces Graminis ◽  
Root Infection ◽  
Root Death ◽  
Meristematic Region ◽  
Germ Tubes ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

Abstract A description is provided for Gaeumannomyces graminis var. tritici. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Gramineae, especially Triticum, Hordeum, Secale, Agropyron and several other grass genera and, more rarely, Sorghum and Zea; also recorded from the roots of plants in other families. DISEASE: Take-all of cereals and grasses (also referred to as deadheads or whiteheads, pietin and pied noir (France), Schwarzbeinigkeit and Ophiobolus Fusskrankheit (Germany), Ophiobolusvoetziekt (Netherlands) and others). Root infection is favoured by soil temperature from 12-20°C (Butler, 1961). Ascospore germ tubes penetrate root hairs and the epidermis in the meristematic region (Weste, 1972) leading to plugging of xylem and root death. GEOGRAPHICAL DISTRIBUTION: (CMI Map 334, ed. 3, 1972). Widespread, especially in temperate zones. Africa; Asia (India, Iran, Japan, USSR): Australasia and Oceania; Europe; North America (Canada, USA); South America (Argentina, Brazil, Chile, Colombia, Uruguay). TRANSMISSION: In soil on infected organic fragments, as runner hyphae on roots of cereals and grasses and, under special conditions, by ascospores. Seed transmission very doubtful (47, 3058).

scholarly journals Dust-related impacts of mining operations on rangeland vegetation and soil: a case study in Yazd province, Iran

2021 ◽  
Author(s):  
Shahab IbrahimPour ◽  
Alireza KhavaninZadeh ◽  
Ruhollah Taghizadeh mehrjardi ◽  
Hans De Boeck ◽  
Alvina Gul
Keyword(s):  
Seed Germination ◽  
Vegetation Cover ◽  
Microbial Respiration ◽  
Germination Rate ◽  
Windward Side ◽  
Leeward Side ◽  
Mining Operations ◽  
Soil Microbial ◽  
Soil Microbial Respiration ◽  
The Impact

Abstract Destructive mining operations are affecting large areas of natural ecosystems, especially in arid lands. The present study aims at investigating the impact of iron mine exploitation on vegetation and soil in Nodoushan (Yazd province, central Iran). Based on the dominant wind, topography, slope, vegetation and soil of the area, soil and vegetation parameters close to ​the mine were recorded and analyzed according to the distance from the mine. In order to obtain the vegetation cover, a transect and plot on the windward and leeward side of the mine, with 100 m intervals and three replicates at each sampling location was used, yielding 96 soil samples. The amount of dust on the vegetation, the seed weight and seed germination rate of Artemisia sp. as the dominant species within the area, and the soil microbial respiration were measured. The relationship between vegetation cover and distance from the mine was not linear, which was due to an interplay between pollution from the mine and local grazing, while other factors did increase or decrease linearly. The results showed that, as the distance from the mine increased, the weight of 1000 seeds of Artemisia sp. was significantly increased from 271 to 494 mg and seed germination rate and soil microbial respiration were significantly increased from 11.7 to 48.4 % and from 4.5 to 5.9 mg CO2 g− 1 soil day− 1 respectively, while the amount of dust significantly decreased from 43.5 to 6 mg (g plant)−1 between the distance of 100 to 600 m from the mine in the leeward direction. A similar trend was observed in the windward side, though negative effects were lower compared to the same distance along the leeward sample locations. The direct and indirect effects on plant growth and health from mining impacts generally decreased linearly with increasing distance from the mine, up to at least 600 m. Our study serves as a showcase for the potential of bio-indicators as a cost-effective method for assessing impacts of mining activities on the surrounding environment.

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