Biological suppression of the saprophytic growth of Gaeumannomyces graminis var. tritici in soil

1987 ◽  
Vol 33 (6) ◽  
pp. 515-519 ◽  
Author(s):  
A. Simon ◽  
K. Sivasithamparam ◽  
G. C. MacNish
Keyword(s):  
Disease Severity ◽  
Gaeumannomyces Graminis ◽  
Seminal Root ◽  
Adjacent Area ◽  
Wheat Seedlings ◽  
Γ Radiation ◽  
Filter Membrane ◽  
History Of ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

The biological suppression of the saprophytic growth of Gaeumannomyces graminis var. tritici in soil in the absence of host roots appeared to be related to suppression of take-all disease of wheat seedlings. When soil collected from a plot which in 1984 and 1985 had grown wheat continuously for 7 and 8 years, respectively, was added at a level of 1% (w/w) to the same soil treated by γ-radiation, saprophytic growth of pigmented hyphae of G. graminis var. tritici on a filter membrane in a soil sandwich was suppressed relative to that occurring in irradiated soil. A soil of the same type from an adjacent area with a history of cereal–pasture alternate rotation did not significantly suppress saprophytic growth of G. graminis var. tritici. Biological suppression of disease of wheat caused by G. graminis var. tritici was tested in a pot bioassay by adding the same two soils, collected in 1985, at a level of 1% (w/w) to fumigated sand infested with oat kernels axenically colonized by the pathogen. Disease severity, measured as the percentage of the seminal root axes with discoloured stele, was reduced by 42 and 6% with the addition of continuous wheat and cereal–pasture rotation soils, respectively, to infested sand, compared with disease severity in unamended, infested sand alone.

Effects of stubble and sowing treatments on take-all of wheat in north-eastern Victoria

1992 ◽  
Vol 32 (5) ◽  
pp. 641 ◽  
Author(s):  
RFde Boer ◽  
GR Steed ◽  
BJ Macauley ◽  
Boer RF De
Keyword(s):  
Disease Severity ◽  
Field Experiments ◽  
Gaeumannomyces Graminis ◽  
Preceding Crop ◽  
North Eastern ◽  
Wheat Stubble ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

The effects of stubble management treatments on take-all (Gaeumannomyces graminis var. tritici) of wheat were examined in 2 field experiments in north-eastern Victoria. Wheat stubble from a preceding crop was left standing, mulched, burnt or incorporated into soil prior to sowing wheat. At Rutherglen in 1984, neither the incidence nor the severity of take-all was affected by these treatments. Although the severity of root symptoms on take-all affected plants at anthesis and the incidence of white heads were very low, sowing with a zero till, triple disc drill resulted in a small but significant (P<0.05) increase in both disease severity and white head incidence (2% tillers with white heads), compared with sowing with a conventional tine drill (0.6% tillers with white heads), regardless of the stubble treatment. At Wilby in 1985, the incidence and severity of take-all in wheat at early tillering was higher in plots in which wheat stubble was incorporated into soil prior to sowing (16% plants affected), than in plots where stubble was left standing, mulched or burnt (2, 3 and 4% plants affected, respectively). At anthesis, however, there were no significant differences in the incidence of affected plants between the 4 stubble treatments (average of 81 % plants affected).

scholarly journals Diversity, Virulence, and 2,4-Diacetylphloroglucinol Sensitivity of Gaeumannomyces graminis var. tritici Isolates from Washington State

2009 ◽  
Vol 99 (5) ◽  
pp. 472-479 ◽  
Author(s):  
Youn-Sig Kwak ◽  
Peter A. H. M. Bakker ◽  
Debora C. M. Glandorf ◽  
Jennifer T. Rice ◽  
Timothy C. Paulitz ◽  
...  
Keyword(s):  
Geographical Origin ◽  
Geographic Origin ◽  
Washington State ◽  
Gaeumannomyces Graminis ◽  
Growing Seasons ◽  
History Of ◽  
Pathogenicity Tests ◽  
Polymerase Chain ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

We determined whether isolates of the take-all pathogen Gaeumannomyces graminis var. tritici become less sensitive to 2,4-diacetylphloroglucinol (2,4-DAPG) during wheat monoculture as a result of exposure to the antibiotic over multiple growing seasons. Isolates of G. graminis var. tritici were baited from roots of native grasses collected from noncropped fields and from roots of wheat from fields with different cropping histories near Lind, Ritzville, Pullman, and Almota, WA. Isolates were characterized by using morphological traits, G. graminis variety-specific polymerase chain reaction and pathogenicity tests. The sensitivity of G. graminis var. tritici isolates to 2,4-DAPG was determined by measuring radial growth of each isolate. The 90% effective dose value was 3.1 to 4.4 μg ml–1 for 2,4-DAPG-sensitive isolates, 4.5 to 6.1 μg ml–1 for moderately sensitive isolates, and 6.2 to 11.1 μg ml–1 for less sensitive isolates. Sensitivity of G. graminis var. tritici isolates to 2,4-DAPG was normally distributed in all fields and was not correlated with geographic origin or cropping history of the field. There was no correlation between virulence on wheat and geographical origin, or virulence and sensitivity to 2,4-DAPG. These results indicate that G. graminis var. tritici does not become less sensitive to 2,4-DAPG during extended wheat monoculture.

Effects of Certain Isolates of Bacteria and Actinomycetes on Gaeumannomyces graminis var. tritici and Take-All of Wheat

1978 ◽  
Vol 26 (6) ◽  
pp. 773 ◽  
Author(s):  
K Sivasithamparam ◽  
CA Parker
Keyword(s):  
Gaeumannomyces Graminis ◽  
Fluorescent Pseudomonads ◽  
Wheat Seedlings ◽  
Apparent Correlation ◽  
Test Organisms ◽  
Unsterile Soil ◽  
Shoot Weight ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

Five isolates each of actinomycetes, bacteria and fluorescent pseudomonads from the roots of wheat were tested for antagonism against Gaeumannomyces graminis var. tritici on agar and in sterile and unsterile soil. There was no apparent correlation between the tests. Effects on the growth of the take-all fungus (TAF) on agar ranged from nil to various degrees of colony deformation and/or inhibition. In a sterile sandy subsoil growing wheat seedlings, all except one isolate had no effect on disease production by a straw inoculum of the TAF. In an unsterile soil, however, measurements of shoot weight indicated that disease was reduced by all five isolates of bacteria singly and in mixture and by four of the five isolates of actinomycetes and a mixture of all five. Although a mixture of all five isolates of fluorescent pseudomonads reduced the disease, none of them produced a similar effect when tested singly. In the absence of the pathogen none of the test organisms significantly increased the shoot weight of wheat.

Effects of tillage and straw mulches on take-all of wheat in the Northern Wimmera of Victoria

1987 ◽  
Vol 27 (3) ◽  
pp. 419 ◽  
Author(s):  
JF Kollmorgen ◽  
PE Ridge ◽  
RFde Boer
Keyword(s):  
Weed Control ◽  
Disease Severity ◽  
Disease Incidence ◽  
Conventional Tillage ◽  
Sampling Time ◽  
Gaeumannomyces Graminis ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

In 4 trials in the Northern Wimmera of Victoria, the incidence and severity of take-all of wheat caused by Gaeumannomyces graminis var. tritici were generally unaffected by tillage treatments (nil, chemical weed control; subsurface, blade plough and rod weeder; conventional scarifier, cultivator and harrows). At 1 site at 1 sampling time disease incidence was higher after conventional tillage than after subsurface tillage and at another site in 1 year out of 3, disease severity was greater after nil tillage than after conventional tillage. A stubble mulch of 4 t ha-1 of straw and burial at 5 or 10 cm reduced survival of the take-all fungus in wheat crowns.

A volatile factor inducing transmissible lysis in Gaeumannomyces graminis (Sacc.) Arx and Olivier var. tritici Walker

1975 ◽  
Vol 21 (3) ◽  
pp. 293-300 ◽  
Author(s):  
K. Sivasithamparam ◽  
M. Stukely ◽  
C. A. Parker
Keyword(s):  
Ultraviolet Light ◽  
Uv Light ◽  
Virulent Strain ◽  
Water Extract ◽  
Gaeumannomyces Graminis ◽  
Heat Stable ◽  
History Of ◽  
Sublethal Doses ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

Filtered water extract of Gabalong soil with a recent history of take-all in wheat caused lytic plaques to form in agar cultures of a virulent strain of Gaeumannomyces graminis var. tritici. The plaques resembled those produced by Bdellovibrio on plates seeded with bacteria. However, there was no evidence of the presence of bacteria, viruses, or mycoplasmas.The lytic factor was transmissible in culture filtrates to fresh subcultures of the fungus. Exposure of young healthy colonies to sublethal doses of ultraviolet light also induced transmissible lysis. The lytic factor was heat-stable, passed through a 25-nm filter, and was not affected by nuclease (enzymes) or severe irradiation with UV light. It also induced lysis in several other strains of G. graminis. Lysis was always preceded by a growth-stimulatory effect on the fungus.The lytic factor was active as a volatile chemical which induced transmissible lysis and continued to be formed, apparently as a self-perpetuating agent, in lysing cultures of the fungus.

scholarly journals Bioassay of Undisturbed Soil Cores for the Presence of Gaeumannomyces Graminis Var. Tritici

1973 ◽  
Vol 26 (6) ◽  
pp. 1267 ◽  
Author(s):  
GC Mac Nish ◽  
RL Dodman ◽  
NT Flentje
Keyword(s):  
Main Parameter ◽  
Gaeumannomyces Graminis ◽  
Soil Cores ◽  
Undisturbed Soil ◽  
Wheat Seedlings ◽  
The Core ◽  
Plant Remains ◽  
Undisturbed Soil Cores ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

The presence of viable G. graminis var. tritici in field soil was detected by a bioassay. Wheat seedlings were grown in undisturbed soil cores maintained under standard conditions for 4 weeks. The percentage of roots infected per core was the main parameter chosen to give an estimate of the level of G. graminis var. tritici inoculum in the core. Some variability between cores from the same site was observed, but this could be reduced by taking cores over plant remains within take-all patches. In this way, high and reasonably uniform levels of inoculum could be obtained to study the effect of various treatments on the incidence of G. graminis var. trifici.

scholarly journals Effect of Placement of Inoculum of Gaeumannomyces graminis var. tritici on Severity of Take-all in Winter Wheat

Plant Disease ◽  
2002 ◽  
Vol 86 (3) ◽  
pp. 298-303 ◽  
Author(s):  
Mehdi Kabbage ◽  
William W. Bockus
Keyword(s):  
Disease Severity ◽  
Field Experiments ◽  
Linear Models ◽  
Cultural Practices ◽  
Spatial Location ◽  
Gaeumannomyces Graminis ◽  
Wheat Seed ◽  
Root Diseases ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

Take-all, caused by Gaeumannomyces graminis var. tritici, is one of the most important root diseases of wheat worldwide. Because of the lack of highly effective chemical control, cultural practices, such as crop rotation, play a major role in managing disease severity. In Kansas, many producers do not use these measures and continue to suffer losses from take-all. Greenhouse and field experiments were established to assess the effect of horizontal versus vertical distribution of G. graminis var. tritici inoculum on disease severity. Oat kernel inoculum was placed at 0 (seed level), 5, 10, or 15 cm below the wheat seed or 5, 10, or 15 cm to the side of the wheat seed at a depth of 5 cm. Inoculum spatial location and distance greatly influenced take-all. Experiments showed more severe losses due to take-all when inoculum was placed below the seed than to the side of the seed. Regression analyses were used to develop take-all risk models relating inoculum distance from the seed to yield loss. Quadratic models were a better fit for data from experiments where inoculum was placed to the side of the seed, whereas linear models significantly fit data from experiments where inoculum was positioned below the seed. Within the same direction, take-all decreased as the inoculum was placed at greater distances from the seed, often to insignificant levels at 10 to 15 cm. According to the regression models, significant reduction (≥50%) in take-all might be achieved by plowing under the infested residues (crowns) to depths greater than 15 cm, or placing seed >6.0 cm to the side of inoculum. Therefore, under no-till conditions, sowing parallel to and exactly between the previous years' stubble rows (inoculum) might help manage take-all. These possibilities need to be investigated under field conditions.

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.

Identification of powdery mildew (Erysiphe graminis sp. tritici) and take-all disease (Gaeumannomyces graminis sp. tritici) in wheat (Triticum aestivum L.) by means of leaf reflectance measurements

2006 ◽  
Vol 1 (2) ◽  
pp. 275-288 ◽  
Author(s):  
Simone Graeff ◽  
Johanna Link ◽  
Wilhelm Claupein
Keyword(s):  
Powdery Mildew ◽  
Disease Severity ◽  
Near Infrared ◽  
Plant Stress ◽  
Stress Factors ◽  
Gaeumannomyces Graminis ◽  
Disease Assessment ◽  
Leaf Reflectance ◽  
Reflectance Measurements ◽  
Take All

AbstractThe ability to identify diseases in an early infection stage and to accurately quantify the severity of infection is crucial in plant disease assessment and management. A greenhouse study was conducted to assess changes in leaf spectral reflectance of wheat plants during infection by powdery mildew and take-all disease to evaluate leaf reflectance measurements as a tool to identify and quantify disease severity and to discriminate between different diseases. Wheat plants were inoculated under controlled conditions in different intensities either with powdery mildew or take-all. Leaf reflectance was measured with a digital imager (Leica S1 Pro, Leica, Germany) under controlled light conditions in various wavelength ranges covering the visible and the near-infrared spectra (380–1300 nm). Leaf scans were evaluated by means of L*a*b*-color system. Visual estimates of disease severity were made for each of the epidemics daily from the onset of visible symptoms to maximum disease severity. Reflectance within the ranges of 490780 nm (r2 = 0.69), 510780nm (r2 = 0.74), 5161300nm (r2 = 0.62) and 5401300 nm (r2 = 0.60) exhibited the strongest relationship with infection levels of both powdery mildew and take-all disease. Among the evaluated spectra the range of 490780nm showed most sensitive response to damage caused by powdery mildew and take-all infestation. The results of this study indicated that disease detection and discrimination by means of reflectance measurements may be realized by the use of specific wavelength ranges. Further studies have to be carried out, to discriminate powdery mildew and take-all infection from other plant stress factors in order to develop suitable decision support systems for site-specific fungicide application.

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