scholarly journals Culturing conditions affect biological control activity of Trichoderma atroviride against Rhizoctonia solani in ryegrass

2016 ◽  
Vol 121 (2) ◽  
pp. 461-472 ◽  
Author(s):  
A. Daryaei ◽  
E.E. Jones ◽  
H. Ghazalibiglar ◽  
T.R. Glare ◽  
R.E. Falloon
Keyword(s):  
Biological Control ◽  
Rhizoctonia Solani ◽  
Trichoderma Atroviride ◽  
Control Activity ◽  
Culturing Conditions

Proteomic response of the biological control fungus Trichoderma atroviride to growth on the cell walls of Rhizoctonia solani

2005 ◽  
Vol 47 (6) ◽  
pp. 381-388 ◽  
Author(s):  
Jasmine Grinyer ◽  
Sybille Hunt ◽  
Matthew McKay ◽  
Ben R. Herbert ◽  
Helena Nevalainen
Keyword(s):  
Biological Control ◽  
Rhizoctonia Solani ◽  
Cell Walls ◽  
Trichoderma Atroviride ◽  
Proteomic Response

scholarly journals Characterization of Genes Involved in Biosynthesis of a Novel Antibiotic from Burkholderia cepacia BC11 and Their Role in Biological Control of Rhizoctonia solani

1998 ◽  
Vol 64 (10) ◽  
pp. 3939-3947 ◽  
Author(s):  
Yaowei Kang ◽  
Russell Carlson ◽  
Wendy Tharpe ◽  
Mark A. Schell
Keyword(s):  
Biological Control ◽  
Rhizoctonia Solani ◽  
Burkholderia Cepacia ◽  
Biochemical Characterization ◽  
Genetic Manipulation ◽  
Damping Off ◽  
Control Activity ◽  
Soil Isolate ◽  
Insight Into

ABSTRACT Genetic manipulation of fluorescent pseudomonads has provided major insight into their production of antifungal molecules and their role in biological control of plant disease. Burkholderia cepaciaalso produces antifungal activities, but its biological control activity is much less well characterized, in part due to difficulties in applying genetic tools. Here we report genetic and biochemical characterization of a soil isolate of B. cepacia relating to its production of an unusual antibiotic that is very active against a variety of soil fungi. Purification and preliminary structural analyses suggest that this antibiotic (called AFC-BC11) is a novel lipopeptide associated largely with the cell membrane. Analysis of conditions for optimal production of AFC-BC11 indicated stringent environmental regulation of its synthesis. Furthermore, we show that production of AFC-BC11 is largely responsible for the ability ofB. cepacia BC11 to effectively control the damping-off of cotton caused by the fungal pathogen Rhizoctonia solani in a gnotobiotic system. Using Tn5 mutagenesis, we identified, cloned, and characterized a region of the genome of strain BC11 that is required for production of this antifungal metabolite. DNA sequence analysis suggested that this region encodes proteins directly involved in the production of a nonribosomally synthesized lipopeptide.

scholarly journals Effect of Plant Extracts and Biological control agents on Rhizoctonia solani Kuhn

2021 ◽  
Vol 735 (1) ◽  
pp. 012079
Author(s):  
Muneer Saeed M. Al-Baldawy ◽  
Ahed A A H Matloob ◽  
Mohammed K. N. Almammory
Keyword(s):  
Biological Control ◽  
Rhizoctonia Solani ◽  
Plant Extracts ◽  
Biological Control Agents

Biological control of Fusarium wilt of cucumber with nonpathogenic isolates of Fusarium oxysporum

1987 ◽  
Vol 33 (5) ◽  
pp. 349-353 ◽  
Author(s):  
T. C. Paulitz ◽  
C. S. Park ◽  
R. Baker
Keyword(s):  
Biological Control ◽  
Fusarium Oxysporum ◽  
Infection Rate ◽  
Fusarium Wilt ◽  
Disease Incidence ◽  
Infection Rates ◽  
Control Activity ◽  
Significant Difference ◽  
Cucumber Roots ◽  
Linear Regressions

Nonpathogenic isolates of Fusarium oxysporum were obtained from surface-disinfested, symptomless cucumber roots grown in two raw (nonautoclaved) soils. These isolates were screened for pathogenicity and biological control activity against Fusarium wilt of cucumber in raw soil infested with Fusarium oxysporum f. sp. cucumerinum (F.o.c.). The influence of three isolates effective in inducing suppressiveness and three ineffective isolates on disease incidence over time was tested. The effective isolates reduced the infection rate (R), based on linear regressions of data transformed to loge (1/1 – y). Effective isolate C5 was added to raw soil infested with various inoculum densities of F.o.c. In treatments without C5, the increase in inoculum densities of F.o.c. decreased the incubation period of wilt disease, but there was no significant difference in infection rate among the inoculum density treatments. Isolate C5 reduced the infection rate at all inoculum densities of F.o.c. Various inoculum densities of C5 were added to raw soils infested with 1000 cfu/g of F.o.c. In the first trial, infection rates were reduced only in the treatment with 10 000 cfu/g of C5; in the second trial, infection rates were reduced in treatments with 10 000 and 30 000 cfu/g of C5.

scholarly journals Cuticular hydrocarbons discriminate cryptic Macrolophus species (Hemiptera: Miridae)

2012 ◽  
Vol 102 (6) ◽  
pp. 624-631 ◽  
Author(s):  
C. Gemeno ◽  
N. Laserna ◽  
M. Riba ◽  
J. Valls ◽  
C. Castañé ◽  
...  
Keyword(s):  
Biological Control ◽  
Cuticular Hydrocarbons ◽  
Cross Validation ◽  
Molecular Genetic ◽  
Cuticular Hydrocarbon ◽  
Hydrocarbon Composition ◽  
Dark Spot ◽  
Prediction Errors ◽  
Control Activity ◽  
Genetic Studies

AbstractMacrolophus pygmaeus is commercially employed in the biological control of greenhouse and field vegetable pests. It is morphologically undistinguishable from the cryptic species M. melanotoma, and this interferes with the evaluation of the biological control activity of M. pygmaeus. We analysed the potential of cuticular hydrocarbon composition as a method to discriminate the two Macrolophus species. A third species, M. costalis, which is different from the other two species by having a dark spot at the tip of the scutellum, served as a control. Sex, diet and species, all had significant effects in the cuticular hydrocarbon profiles, but the variability associated to sex or diet was smaller than among species. Discriminant quadratic analysis of cuticular hydrocarbons confirmed the results of previous molecular genetic studies and showed, using cross-validation methods, that M. pygmaeus can be discriminated from M. costalis and M. melanotoma with prediction errors of 6.75% and 0%, respectively. Therefore, cuticular hydrocarbons can be used to separate M. pygmaeus from M. melanotoma reliably.

scholarly journals Mechanistically Compatible Mixtures of Bacterial Antagonists Improve Biological Control of Fire Blight of Pear

2011 ◽  
Vol 101 (1) ◽  
pp. 113-123 ◽  
Author(s):  
V. O. Stockwell ◽  
K. B. Johnson ◽  
D. Sugar ◽  
J. E. Loper
Keyword(s):  
Biological Control ◽  
Plant Disease ◽  
Fire Blight ◽  
Biological Control Agent ◽  
Field Trials ◽  
Control Agent ◽  
Extracellular Protease ◽  
Peptide Antibiotics ◽  
Biological Control Agents ◽  
Control Activity

Mixtures of biological control agents can be superior to individual agents in suppressing plant disease, providing enhanced efficacy and reliability from field to field relative to single biocontrol strains. Nonetheless, the efficacy of combinations of Pseudomonas fluorescens A506, a commercial biological control agent for fire blight of pear, and Pantoea vagans strain C9-1 or Pantoea agglomerans strain Eh252 rarely exceeds that of individual strains. A506 suppresses growth of the pathogen on floral colonization and infection sites through preemptive exclusion. C9-1 and Eh252 produce peptide antibiotics that contribute to disease control. In culture, A506 produces an extracellular protease that degrades the peptide antibiotics of C9-1 and Eh252. We hypothesized that strain A506 diminishes the biological control activity of C9-1 and Eh252, thereby reducing the efficacy of biocontrol mixtures. This hypothesis was tested in five replicated field trials comparing biological control of fire blight using strain A506 and A506 aprX::Tn5, an extracellular protease-deficient mutant, as individuals and combined with C9-1 or Eh252. On average, mixtures containing A506 aprX::Tn5 were superior to those containing the wild-type strain, confirming that the extracellular protease of A506 diminished the biological control activity of C9-1 and Eh252 in situ. Mixtures of A506 aprX::Tn5 and C9-1 or Eh252 were superior to oxytetracycline or single biocontrol strains in suppressing fire blight of pear. These experiments demonstrate that certain biological control agents are mechanistically incompatible, in that one strain interferes with the mechanism by which a second strain suppresses plant disease. Mixtures composed of mechanistically compatible strains of biological control agents can suppress disease more effectively than individual biological control agents.

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