Nutritional and environmental factors affecting growth and antifungal activity of a sterile red fungus against Gaeumannomyces graminis var. tritici

1994 ◽  
Vol 72 (2) ◽  
pp. 198-202 ◽  
Author(s):  
M. Shankar ◽  
D. I. Kurtböke ◽  
K. Sivasithamparam
Keyword(s):  
Antifungal Activity ◽  
Nitrogen Sources ◽  
Maximum Growth ◽  
Gaeumannomyces Graminis ◽  
Factors Affecting ◽  
Carbon And Nitrogen ◽  
N Source ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

Growth and antifungal activity of a sterile red fungus against Gaeumannomyces graminis var. tritici (the take-all fungus) in vitro was greatly influenced by nutritional and environmental conditions. The utilization by the sterile red fungus of various carbon and nitrogen sources differed considerably at pH 5.5 and 6.5. Maximum growth of the sterile red fungus occurred when pectin was supplied as the carbon source at both pH levels. As nitrogen sources, NH4H2PO4 supported maximum growth at pH 5.5, whereas Ca(NO3)2 was the best at pH 6.5. Pectin strongly enhanced the antifungal activity of the sterile red fungus towards the take-all fungus as did Ca(NO3)2 supplied as a N source. There was, however, little or no antagonism in the presence of calcium citrate, arabinose, leucine, or arginine. In general, antagonism was optimal at 20 °C and at pH 5.5. Key words: sterile red fungus, Gaeumannomyces graminis var. tritici, biological control.

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.

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 Biological Control of Take-All by Fluorescent Pseudomonas spp. from Chinese Wheat Fields

2011 ◽  
Vol 101 (12) ◽  
pp. 1481-1491 ◽  
Author(s):  
Ming-Ming Yang ◽  
Dmitri V. Mavrodi ◽  
Olga V. Mavrodi ◽  
Robert F. Bonsall ◽  
James A. Parejko ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Restriction Analysis ◽  
Gaeumannomyces Graminis ◽  
Mass Spectrometry Analysis ◽  
In Vitro Tests ◽  
Spectrometry Analysis ◽  
Pseudomonas Spp ◽  
Fluorescent Pseudomonas ◽  
Take All

Take-all disease of wheat caused by the soilborne fungus Gaeumannomyces graminis var. tritici is one of the most important root diseases of wheat worldwide. Bacteria were isolated from winter wheat from irrigated and rainfed fields in Hebei and Jiangsu provinces in China, respectively. Samples from rhizosphere soil, roots, stems, and leaves were plated onto King's medium B agar and 553 isolates were selected. On the basis of in vitro tests, 105 isolates (19% of the total) inhibited G. graminis var. tritici and all were identified as Pseudomonas spp. by amplified ribosomal DNA restriction analysis. Based on biocontrol assays, 13 strains were selected for further analysis. All of them aggressively colonized the rhizosphere of wheat and suppressed take-all. Of the 13 strains, 3 (HC9-07, HC13-07, and JC14-07, all stem endophytes) had genes for the biosynthesis of phenazine-1-carboxylic acid (PCA) but none had genes for the production of 2,4-diacetylphloroglucinol, pyoluteorin, or pyrrolnitrin. High-pressure liquid chromatography (HPLC) analysis of 2-day-old cultures confirmed that HC9-07, HC13-07, and JC14-07 produced PCA but no other phenazines were detected. HPLC quantitative time-of-flight 2 mass-spectrometry analysis of extracts from roots of spring wheat colonized by HC9-07, HC13-07, or Pseudomonas fluorescens 2-79 demonstrated that all three strains produced PCA in the rhizosphere. Loss of PCA production by strain HC9-07 resulted in a loss of biocontrol activity. Analysis of DNA sequences within the key phenazine biosynthesis gene phzF and of 16S rDNA indicated that strains HC9-07, HC13-07, and JC14-07 were similar to the well-described PCA producer P. fluorescens 2-79. This is the first report of 2-79-like bacteria being isolated from Asia.

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