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.

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.

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.

Effect of nitrogen supply on rhizosphere interactions and take-all disease of wheat

1991 ◽  
Vol 37 (1) ◽  
pp. 42-51 ◽  
Author(s):  
M. E. Leggett ◽  
K. Sivasithamparam ◽  
M. J. McFarlane
Keyword(s):  
Nitrogen Deficiency ◽  
Gaeumannomyces Graminis ◽  
Fluorescent Pseudomonads ◽  
Root Weight ◽  
Fluorescent Pseudomonad ◽  
Fresh Weight ◽  
Colony Forming Units ◽  
Rhizosphere Interactions ◽  
Shoot Weight ◽  
Take All

The effect of NH4NO3 on the expression of take-all in wheat and on the ability of fluorescent pseudomonad bacteria to decrease the growth of the pathogen and the symptoms of the disease was examined in a nitrogen-deficient acidic soil from Western Australia. Application of NH4NO3 increased the fresh weight of shoots, decreased root weight and length, and offset some of the deleterious effects of infection. Inoculation with Gaeumannomyces graminis var. triciti reduced shoot weight and root weight and length at all but the highest level of applied nitrogen. Fluorescent pseudomonads applied to wheat seed (at approximately 108 colony-forming units/seed) reduced seed germination and failed to reduce the severity of take-all expressed as weight or length of shoots or N content. Although the density of black runner hyphae of G. graminis var. triciti was reduced at 40 days and the proportion of root colonized by the pathogen was lower at 28 days with bacterization under severe nitrogen deficiency, no effect of the bacteria was observed if N was added. Key words: Gaeumannomyces graminis var. triciti, fluorescent pseudomonads, wheat, nitrogen.

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 Activity of Fengycin and Iturin A Isolated From Bacillus subtilis Z-14 on Gaeumannomyces graminis Var. tritici and Soil Microbial Diversity

2021 ◽  
Vol 12 ◽  
Author(s):  
Jiawen Xiao ◽  
Xiaojun Guo ◽  
Xinlei Qiao ◽  
Xuechao Zhang ◽  
Xiaomeng Chen ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Relative Abundance ◽  
Gaeumannomyces Graminis ◽  
Control Effect ◽  
Soil Bacterial Diversity ◽  
Soil Microbial Diversity ◽  
Wheat Seedlings ◽  
Iturin A ◽  
Soil Microbial ◽  
Take All

Bacillus subtilis Z-14 can inhibit phytopathogenic fungi, and is used as a biocontrol agent for wheat take-all disease. The present study used the soil-borne fungus Gaeumannomyces graminis var. tritici (Ggt), which causes wheat take-all disease, and the soil microbial community as indicators, and investigated the antifungal effects of fengycin and iturin A purified from strain Z-14 using high performance liquid chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, respectively. The results showed that fengycin destroyed the internal structure of Ggt cells by digesting the cytoplasm and organelles, forming vacuoles, and inducing hyphal shrinkage and distortion. Iturin A induced cell wall disappearance, membrane degeneration, intracellular material shrinkage, and hyphal fragmentation. A biocontrol test demonstrated a 100% control effect on wheat take-all when wheat seedlings were treated with fengycin at 100 μg/ml or iturin A at 500 μg/ml. Iturin A and fengycin both reduced the relative abundance of Aspergillus and Gibberella. At the genus level, iturin A reduced the relative abundance of Mortierella and Myrothecium, while fengycin reduced that of Fusarium. Only fengycin treatment for 7 days had a significant effect on soil bacterial diversity.

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