Characterization and aggressiveness of take-all root rot pathogens isolated from symptomatic bermudagrass putting greens

2021 ◽  
Author(s):  
Cameron Stephens ◽  
Travis W Gannon ◽  
Marc Cubeta ◽  
Tim L. Sit ◽  
Jim Kerns
Keyword(s):  
Plant Tissue ◽  
Root Rot ◽  
Pathogen Detection ◽  
Infected Plant ◽  
Gaeumannomyces Graminis ◽  
In Planta ◽  
High Resolution Melt ◽  
Putting Greens ◽  
Ultradwarf Bermudagrass ◽  
Take All

Take-all root rot is a disease of ultradwarf bermudagrass putting greens caused by Gaeumannomyces graminis (Gg), Gaeumannomyces sp. (Gx), Gaeumannomyces graminicola (Ggram), Candidacolonium cynodontis (Cc), and Magnaporthiopsis cynodontis (Mc). Many etiological and epidemiological components of this disease remain unknown. Improving pathogen identification and our understanding of the aggressiveness of these pathogens along with growth at different temperatures will advance our knowledge of disease development to optimize management strategies. Take-all root rot pathogens were isolated from symptomatic bermudagrass root and stolon pieces from 16 different golf courses. Isolates of Gg, Gx, Ggram, Cc, and Mc were used to inoculate ‘Champion’ bermudagrass in an in planta aggressiveness assay. Each pathogen was also evaluated at 10, 15, 20, 25, 30, and 35C to determine growth temperature optima. Infected plant tissue was used to develop a real-time PCR high resolution melt assay for pathogen detection. This assay was able to differentiate each pathogen directly from infected plant tissue using a single primer pair. In general, Ggram, Gg, and Gx were the most aggressive while Cc and Mc exhibited moderate aggressiveness. Pathogens were more aggressive when incubated at 30C compared to 20C. While they grew optimally between 24.4 and 27.8C, pathogens exhibited limited growth at 35C and no growth at 10C. These data provide important information on this disease and its causal agents that may improve take-all root rot management.

scholarly journals Pseudomonas synxantha 2-79 Transformed with Pyrrolnitrin Biosynthesis Genes Has Improved Biocontrol Activity Against Soilborne Pathogens of Wheat and Canola

2020 ◽  
Vol 110 (5) ◽  
pp. 1010-1017
Author(s):  
Jibin Zhang ◽  
Dmitri V. Mavrodi ◽  
Mingming Yang ◽  
Linda S. Thomashow ◽  
Olga V. Mavrodi ◽  
...  
Keyword(s):  
Root Rot ◽  
Fusarium Culmorum ◽  
Pythium Ultimum ◽  
Gaeumannomyces Graminis ◽  
Wild Type ◽  
Wheat Roots ◽  
Recombinant Strains ◽  
Rhizoctonia Root Rot ◽  
Take All

A four-gene operon (prnABCD) from Pseudomonas protegens Pf-5 encoding the biosynthesis of the antibiotic pyrronitrin was introduced into P. synxantha (formerly P. fluorescens) 2-79, an aggressive root colonizer of both dryland and irrigated wheat roots that naturally produces the antibiotic phenazine-1-carboxylic acid and suppresses both take-all and Rhizoctonia root rot of wheat. Recombinant strains ZHW15 and ZHW25 produced both antibiotics and maintained population sizes in the rhizosphere of wheat that were comparable to those of strain 2-79. The recombinant strains inhibited in vitro the wheat pathogens Rhizoctonia solani anastomosis group 8 (AG-8) and AG-2-1, Gaeumannomyces graminis var. tritici, Sclerotinia sclerotiorum, Fusarium culmorum, and F. pseudograminearum significantly more than did strain 2-79. Both the wild-type and recombinant strains were equally inhibitory of Pythium ultimum. When applied as a seed treatment, the recombinant strains suppressed take-all, Rhizoctonia root rot of wheat, and Rhizoctonia root and stem rot of canola significantly better than did wild-type strain 2-79.

scholarly journals Take-All Root Rot of St. Augustinegrass: First Report in Mississippi

Plant Disease ◽  
2000 ◽  
Vol 84 (8) ◽  
pp. 921-921
Author(s):  
M. Tomaso-Peterson ◽  
L. E. Trevathan ◽  
M. S. Gonzalez
Keyword(s):  
Tall Fescue ◽  
Root Rot ◽  
Potato Dextrose Agar ◽  
Gaeumannomyces Graminis ◽  
Peat Moss ◽  
Infested Soil ◽  
First Report ◽  
Plant Parts ◽  
Home Lawns ◽  
Take All

Take-all root rot has been reported as a destructive disease of St. Augustinegrass home lawns in Florida and Alabama (1). In June 1998 and 1999, St. Augustinegrass home lawns in central Mississippi developed chlorotic, thinning patches ranging from 0.5 to 4.5 m in diameter. By August of each summer, plants within affected patches were necrotic and dead. Roots of affected St. Augustinegrass were necrotic and shorter than those of unaffected plants; nodes on stolons were necrotic, and lesions developed on internodes. Ectotrophic runner hyphae and dark brown, lobed hyphopodia were visible on roots and aboveground plant parts, respectively. Symptomatic tissues collected from St. Augustinegrass home lawns were plated onto potato dextrose agar (PDA); the incitant of take-all root rot, Gaeumannomyces graminis(Sacc.) Arx & Olivier var. graminis, was isolated. Verification of G. graminis var. graminis was based on colony morphology and taxonomic identification consistent with the description by Walker (2). G. graminis var. graminis isolated from symptomatic St. Augustinegrass was grown on sterile tall fescue seed and incorporated into sterile sand/peat moss mix. Asymptomatic St. Augustinegrass sprigs were washed, and roots were removed prior to planting in infested and noninfested soil. Plants were cultured in the greenhouse for 60 days. St. Augustinegrass planted into noninfested soil was asymptomatic while plants collected from G. graminis var. graminis-infested soil were symptomatic for take-all root rot. Crowns and roots of affected plants were necrotic; leaves were chlorotic and necrotic. Both runner hyphae and lobed hyphopodia were visible. G. graminis var. graminis was reisolated from symptomatic tissues and confirmed as the incitant of take-all root rot. This is the first report of take-all root rot of St. Augustinegrass in Mississippi. References: (1) M. Elliott. Plant Dis. 77:206, 1993. (2) J. Walker. Trans. Br. Mycol. Soc. 58:427, 1972.

Effects of row spacing, seeding rate and seed-placed phosphorus on root diseases of spring wheat and barley under zero tillage

1998 ◽  
Vol 78 (1) ◽  
pp. 145-150 ◽  
Author(s):  
K. L. Bailey ◽  
Guy P. Lafond ◽  
Daryl Domitruk
Keyword(s):  
Spring Wheat ◽  
Root Rot ◽  
Cultural Practices ◽  
Wheat Yield ◽  
Gaeumannomyces Graminis ◽  
Row Spacing ◽  
Zero Tillage ◽  
Seeding Rate ◽  
Root Diseases ◽  
Take All

Changes in tillage and other agronomic practices have shown benefits of increased grain yield for many crops, but these changes may alter the micro-environment resulting in changes to populations of disease-causing agents and other micro-organisms. This study examined the effects of row spacing (10, 20, 30 cm), seeding rate (54, 108, 161 kg ha−1 for barley; 67, 134, 202 kg ha−1 for spring wheat) and seed-placed phosphorus (0, 8, 16 kg ha−1) on root diseases in spring wheat and barley using a zero-tillage production system in four environments. Root rot severity was assessed by visual ratings and the causal agents were identified. Analyses of variance indicated significant differences in root rot severity and the incidence of some causal agents for the main treatment effects (i.e. row spacing, seeding rate, seed-placed phosphorus) and no significant interactions between locations, years, and cultural practices. Contrasts of treatment means showed that higher rates of seeding decreased root rot severity and the incidence of Fusarium in wheat but these effects were small (less than 6%). The higher rates of monoammonium phosphate fertilizer reduced root rot severity in barley by 7% and the incidence of Gaeumannomyces graminis var. tritici in wheat by greater than 40%. Wider row spacings showed a small reduction of 6% in root rot severity in wheat but mostly had no effect on root diseases. Wheat yields were negatively associated with root rot severity in three of four environments. Fertility, root rot severity, and seeding rate had the greatest impact on wheat yield. Root diseases did not affect barley yields. Therefore, the use of wider row spacings and higher seeding rates with zero tillage practices will not lead to adverse effects on root diseases in wheat and barley. Phosphorus fertilizer should be used to reduce losses resulting from take-all disease in wheat. Key words: Zero tillage, cultural practices, common root rot, take-all, cereals

scholarly journals Bacillus sp. L324-92 for Biological Control of Three Root Diseases of Wheat Grown with Reduced Tillage

1997 ◽  
Vol 87 (5) ◽  
pp. 551-558 ◽  
Author(s):  
Dal-Soo Kim ◽  
R. James Cook ◽  
David M. Weller
Keyword(s):  
Biological Control ◽  
Root Rot ◽  
Gaeumannomyces Graminis ◽  
Limiting Factors ◽  
Bacillus Species ◽  
Bacillus Sp ◽  
Pythium Irregulare ◽  
Root Diseases ◽  
Rhizoctonia Root Rot ◽  
Take All

Strain L324-92 is a novel Bacillus sp. with biological activity against three root diseases of wheat, namely take-all caused by Gaeumannomyces graminis var. tritici, Rhizoctonia root rot caused by Rhizoctonia solani AG8, and Pythium root rot caused mainly by Pythium irregulare and P. ultimum, that exhibits broad-spectrum inhibitory activity and grows at temperatures from 4 to 40°C. These three root diseases are major yieldlimiting factors for wheat in the U.S. Inland Pacific Northwest, especially wheat direct-drilled into the residue of a previous cereal crop. Strain L324-92 was selected from among approximately 2,000 rhizosphere/rhizoplane isolates of Bacillus species isolated from roots of wheat collected from two eastern Washington wheat fields that had long histories of wheat. Roots were washed, heat-treated (80°C for 30 min), macerated, and dilution-plated on 1/10-strength tryptic soy agar. Strain L324-92 inhibited all isolates of G. graminis var. tritici, Rhizoctonia species and anastomosis groups, and Pythium species tested on agar at 15°C; provided significant suppression of all three root diseases at 15°C in growth chamber assays; controlled either Rhizoctonia root rot, takeall, or both; and increased yields in field tests in which one or more of the three root diseases of wheats were yield-limiting factors. The ability of L324-92 to grow at 4°C probably contributes to its biocontrol activity on direct-drilled winter and spring wheat because, under Inland Northwest conditions, leaving harvest residues of the previous crop on the soil surface keeps soils cooler compared with tilled soils. These results suggest that Bacillus species with desired traits for biological control of wheat root diseases are present within the community of wheat rhizosphere microorganisms and can be recovered by protocols developed earlier for isolation of fluorescent Pseudomonas species effective against take-all.

scholarly journals Biological Control of Wheat Root Diseases by the CLP-Producing Strain Pseudomonas fluorescens HC1-07

2014 ◽  
Vol 104 (3) ◽  
pp. 248-256 ◽  
Author(s):  
Ming-Ming Yang ◽  
Shan-Shan Wen ◽  
Dmitri V. Mavrodi ◽  
Olga V. Mavrodi ◽  
Diter von Wettstein ◽  
...  
Keyword(s):  
Biological Control ◽  
Pseudomonas Fluorescens ◽  
Root Rot ◽  
Gaeumannomyces Graminis ◽  
Protease Production ◽  
Ionization Mass ◽  
Soilborne Disease ◽  
Rhizoctonia Root Rot ◽  
Take All

Pseudomonas fluorescens HC1-07, previously isolated from the phyllosphere of wheat grown in Hebei province, China, suppresses the soilborne disease of wheat take-all, caused by Gaeumannomyces graminis var. tritici. We report here that strain HC1-07 also suppresses Rhizoctonia root rot of wheat caused by Rhizoctonia solani AG-8. Strain HC1-07 produced a cyclic lipopeptide (CLP) with a molecular weight of 1,126.42 based on analysis by electrospray ionization mass spectrometry. Extracted CLP inhibited the growth of G. graminis var. tritici and R. solani in vitro. To determine the role of this CLP in biological control, plasposon mutagenesis was used to generate two nonproducing mutants, HC1-07viscB and HC1-07prtR2. Analysis of regions flanking plasposon insertions in HC1-07prtR2 and HC1-07viscB revealed that the inactivated genes were similar to prtR and viscB, respectively, of the well-described biocontrol strain P. fluorescens SBW25 that produces the CLP viscosin. Both genes in HC1-07 were required for the production of the viscosin-like CLP. The two mutants were less inhibitory to G. graminis var. tritici and R. solani in vitro and reduced in ability to suppress take-all. HC1-07viscB but not HC-07prtR2 was reduced in ability to suppress Rhizoctonia root rot. In addition to CLP production, prtR also played a role in protease production.

Detoxification of phytoanticipins and phytoalexins by phytopathogenic fungi

1995 ◽  
Vol 73 (S1) ◽  
pp. 518-525 ◽  
Author(s):  
Hans D. VanEtten ◽  
Robert W. Sandrock ◽  
Catherine C. Wasmann ◽  
Scott D. Soby ◽  
Kevin McCluskey ◽  
...  
Keyword(s):  
De Novo ◽  
Infected Plant ◽  
Resistance Mechanisms ◽  
Phytopathogenic Fungi ◽  
Gaeumannomyces Graminis ◽  
In Planta ◽  
Detoxifying Enzymes ◽  
Key Words Disease ◽  
Key Words Disease Resistance

Most plants synthesize antimicrobial compounds as part of normal plant development (i.e., phytoanticipins) or synthesize such compounds de novo when challenged by microorganisms (i.e., phytoalexins). The presumed role of these plant antibiotics is to protect the plant from disease. However, many phytopathogenic fungi have enzymes that can detoxify the phytoanticipins or phytoalexins produced by their host. This may be a means that these pathogens have evolved to circumvent resistance mechanisms based on the production of plant antibiotics. Many of the phytoanticipin- and phytoalexin-detoxifying enzymes produced by phytopathogenic fungi have biochemical and regulatory properties that would indicate the phytoanticipins and phytoalexins produced by their host are their normal substrates. In addition, their activity, enzymatic products, or transcripts can be detected in infected plant tissue suggesting that they are functioning in planta during pathogenesis. Specific mutations have been made by transformation-mediated gene-disruption procedures that eliminate the ability of Gaeumannomyces graminis var. avenae, Gloeocercospora sorghi, and Nectria haematococca to detoxify the phytoanticipins or phytoalexins produced by their hosts. The effect of these mutations on pathogenicity indicates a requirement for detoxifying enzymes in G. graminis var. avenae but not in G. sorghi or N. haematococca. Key words: disease resistance, pathogenicity mechanisms, isoflavonoids, saponins, cyanide.

Changes in take-all (Gaeumannomyces graminis var. tritici), Rhizoctonia root rot (Rhizoctonia solani) and soil pH in continuous wheat with annual applications of nitrogenous fertiliser in Western Australia

1988 ◽  
Vol 28 (3) ◽  
pp. 333 ◽  
Author(s):  
GC MacNish
Keyword(s):  
Soil Ph ◽  
Root Rot ◽  
Ammonium Nitrogen ◽  
Gaeumannomyces Graminis ◽  
Continuous Cropping ◽  
Rhizoctonia Root Rot ◽  
Continued Use ◽  
Effect On Yield ◽  
Gaeumannomyces Graminis Var Tritici ◽  
Take All

Experiments were conducted to test the hypotheses that: (i) continuous cropping with wheat would lead to a decline in take-all, (ii) ammonium nitrogen would reduce take-all compared with nitrate nitrogen, and (iii) that both sources of nitrogen would lead to a decline in soil pH. Attempts were also made to confirm that rhizoctonia root rot would vary unpredictably in continuous wheat and would be reduced by nitrogen. Wheat was grown without nitrogen (Nil) or with sodium nitrate (SN) or ammonium sulfate (AS) for 11, 10 and 9 consecutive years at Newdegate, Esperance and Mount Barker respectively. Rates of nitrogen were 50, 25 and 45 kg ha-1 at Newdegate, Esperance and Mount Barker respectively. A decline in take-all incidence was established at Newdegate, and plots treated with AS generally had a lower take-all incidence than did plots without nitrogen or treated with SN. At Esperance, a decline in take-all incidence was established only in AS treated plots. Take-all incidence was lower in plots treated with AS than plots without nitrogen or treated with SN in 6 years out of 10 at Esperance. No take-all decline was observed at Mount Barker and take-all incidence was rarely lower in plots treated with AS than in those without nitrogen or treated with SN. All treatments reduced soil pH at Newdegate and Esperance, which were weakly buffered sites, but at Mount Barker (a highly buffered site) only AS reduced pH. Rhizoctonia root rot was not found at Mount Barker. At Newdegate and Esperance it first occurred in the eighth and fifth crops respectively. Incidence peaked at about 60% of plants being affected in the ninth crop at Newdegate and 95% in year 7 at Esperance, and then declined to less than 5% at both sites. Applications of nitrogen had no effect on incidence of rhizoctonia root rot. Yields varied considerably between sites and years. Combining results for all years at each site showed that AS increased yield at all sites and SN increased yields at Newdegate and Mount Barker compared with no nitrogen. The continued use of AS at Mount Barker eventually had an adverse effect on yield.

scholarly journals Potential biological control of take-all disease in perennial ryegrass

2019 ◽  
Vol 72 ◽  
pp. 213-220
Author(s):  
Abdullah Umar ◽  
Diwakar R.W. Kandula ◽  
John G. Hampton ◽  
M. Phil Rolston ◽  
Soonie F. Chng
Keyword(s):  
Biological Control ◽  
New Zealand ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Root Rot ◽  
Dry Matter ◽  
Gaeumannomyces Graminis ◽  
Trichoderma Atroviride ◽  
Pasture Grass ◽  
Take All

Perennial ryegrass (Lolium perenne) is the major pasture grass in New Zealand but is highly susceptible to take-all disease, caused by the root-rot pathogen Gaeumannomyces graminis (Gg). Isolates of the fungus Trichoderma atroviride are known to control Gg but it is not known if a mixture of isolates would be more effective than individual ones. Soil from a field naturally infested with Gg was placed in containers in a glasshouse and sown with ryegrass seeds then treated with one of three Trichoderma atroviride isolates or a mixture of all three isolates. All T. atroviride treatments significantly increased shoot dry matter by 46–73% and root dry matter by 42–62% compared with the control but a mixture of isolates was no more effective than individual isolates. Application of T. atroviride also significantly decreased root disease severity, which was negatively correlated with root dry matter. Takeall in pastures could possibly be controlled by overdrilling grass with a single isolate of T. atroviride.

scholarly journals Cloning, Characterization, and Transcription of Three Laccase Genes from Gaeumannomyces graminis var. tritici, the Take-All Fungus

2002 ◽  
Vol 68 (3) ◽  
pp. 1305-1311 ◽  
Author(s):  
Anastasia P. Litvintseva ◽  
Joan M. Henson
Keyword(s):  
Expression Patterns ◽  
Wheat Plant ◽  
Gaeumannomyces Graminis ◽  
Copper Binding ◽  
In Planta ◽  
Reverse Transcription Pcr ◽  
Filamentous Ascomycete ◽  
Laccase Genes ◽  
Take All

ABSTRACT Gaeumannomyces graminis var. tritici, a filamentous ascomycete, is an important root pathogen of cereals that causes take-all disease and results in severe crop losses worldwide. Previously we identified a polyphenol oxidase (laccase) secreted by the fungus when induced with copper. Here we report cloning and partial characterization of three laccase genes (LAC1, LAC2, and LAC3) from G. graminis var. tritici. Predicted polypeptides encoded by these genes had 38 to 42% amino acid sequence identity and had conserved copper-binding sites characteristic of laccases. The sequence of the LAC2 predicted polypeptide matched the N-terminal sequence of the secreted laccase that we purified in earlier studies. We also characterized expression patterns of these genes by reverse transcription-PCR. LAC1 was transcribed constitutively, and transcription of LAC2 was Cu inducible. All three genes were transcribed in planta; however, transcription of LAC3 was observed only in planta or in the presence of host (wheat) plant homogenate.

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