scholarly journals The Effect of Various pH Medium on the Secondary Metabollites Production from Trichoderma harzianum T10 to Control Damping Off on Cucumber Seedlings

2020 ◽  
Vol 3 (2) ◽  
pp. 65
Author(s):  
Nur Chalimah ◽  
Loekas Soesanto ◽  
Woro Sri Suharti

Damping-off is one of the main diseases in cucumber seedlings caused by Pythium sp. Secondary metabolites of Trichoderma harzianum T10 can conduct the control of the disease. The pH of the medium influences the production of secondary metabolites. The research aimed to determine the effective pH medium on production of T. harzianum T10 secondary metabolites, and the effect of the T. harzianum T10 secondary metabolites application in damping-off disease control also to the growth of cucumber seedling. The research was consist of two steps; 1) in vitro assay with various pH levels 5; 3; 3.5; 4; 4.5; 5.5; 6; 6.5; and 7, 2) In planta treatments consisted of control, fungicide (Mancozeb), secondary metabolites in pH 5 and 5.5 with the concentration of 5, 10 and 15% each. The research showed that: 1) the effective pH medium for the production of T. harzianum T10 secondary metabolites was 5 and 5.5. 2) application of the T. harzianum T10 secondary metabolites on pH 5 and 5.5 with a concentration of 5, 10, and 15% could decrease the disease incidence and support cucumber seedling growth.

2020 ◽  
Vol 12 (2) ◽  
pp. 226-234
Author(s):  
Loekas Soesanto ◽  
Hidayatul Ilahiyyah ◽  
Endang Mugiastuti ◽  
Abdul Manan ◽  
Rostaman Rostaman

Trichoderma harzianum is effective for controlling soil-borne pathogenic fungi and producing secondary metabolites. When applied in the field, the raw secondary metabolites are quickly decreased directly by sunlight. One strategy to avoid degradation is the use of tapioca fluor liquid formula for biological control agents. This research aimed to obtain the most effective concentration of tapioca flour in development of raw secondary metabolites of Trichoderma harzianum T10, its effect on damping-off and growth of cucumber. This research was carried out at the screen house and the Plant Protection Laboratory, Faculty of Agriculture, Jenderal Soedirman University from September 2017 up to January 2018. The study was conducted in two stages, i.e., in vitro and in planta. The in vitro stage used completely randomized design with five repetitions and five treatments consisted of T. harzianum T10 in Potato Dextrose Broth, and in 0.5; 1; 1.5; and 2% of tapioca flour media. In in planta, randomized block design was used with five repetitions and six treatments consisted of control, T. harzianum T10 in PDB, and in 0.5; 1; 1.5, and 2% of tapioca flour media. Variables observed were density of conidia, disease incubation period, disease incidence, AUDPC, maximum growth potential, germination ability, plant height, canopy fresh weight, root length, and fresh root weight. Result of the research showed that the highest conidial density (1.23 x 107 conidia mL-1) of T. harzianum T10 was found in 2% tapioca flour with an increase of 63.28% compared to the PDB. The tapioca flour of 1 and 2%, and PDB could suppress the disease incidence by 81.82%. The lowest AUDPC was at 2% tapioca flour. The raw secondary metabolites could not delay the incubation period significantly and increase cucumber plant growth. The novelty is the use of antagonistic fungi in terms of raw secondary metabolites and the discovery of tapioca flour with the right concentration to produce high conidia density and high raw secondary metabolites. The benefits are to find other cheaper ingredients in promoting antagonistic fungal growth and the use of antagonistic fungal bioactive compounds to control plant pathogen


Toxins ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 696
Author(s):  
Takahito Toyotome ◽  
Katsuhiko Kamei

Trichothecenes are a family of major secondary metabolites produced by some common filamentous fungi, including plant pathogenic and entomopathogenic fungi. It may be considered difficult to conduct a comparison between the toxicities of trichothecenes with consideration of different conditions and cell lines. In the current study, we developed an in vitro assay based on a commercially available system to estimate the translation inhibition, that is, the main toxicity, of trichothecenes. The assay was applied to estimate the inhibition of protein synthesis by trichothecenes. Initially, we examined the assay using trichothecene dissolved in water followed by an assessment of trichothecene solutions dissolved in acetonitrile. The obtained data showed that the assay tolerated the small amount of acetonitrile. The assay examined in this study has the advantages of a short operation time (one day), ease of use, and data stability, as it is a non-cell-based assay whose components are commercially available. It is expected that this assay will contribute to the evaluation of the toxicity of a vast number of trichothecenes.


1995 ◽  
Vol 73 (5) ◽  
pp. 693-700 ◽  
Author(s):  
D. Yang ◽  
L. Bernier ◽  
M. Dessureault

A fungal antagonist, Phaeotheca dimorphospora, was tested for its ability to control damping-off of red pine (Pinus resinosa) caused by Cylindrocladium scoparium. In vitro, the germination of seeds coated with P. dimorphospora microconidia was significantly increased by 10% compared with uncoated seeds. In experiments carried out in Petri dishes, addition of P. dimorphospora into soil significantly reduced the population of C. scoparium and disease incidence. In the greenhouse, application of P. dimorphospora into the top layer of soil reduced pre- and post-emergence damping-off by 79.5%. Under greenhouse conditions, P. dimorphospora stimulated the population of Trichoderma harzianum, a well-known antagonist of soil-borne plant pathogens. In soil treated with P. dimorphospora, the number of propagules of T. harzianum was 100–500 times higher than in the untreated control, whereas the population of C. scoparium decreased rapidly and was not detectable 1 month after sowing. Key words: Phaeotheca dimorphospora, Trichoderma harzianum, Cylindrocladium scoparium, damping-off, biological control, fungal antagonist, Pinus resinosa.


Plant Disease ◽  
2007 ◽  
Vol 91 (4) ◽  
pp. 469-469 ◽  
Author(s):  
D. C. Mavragani ◽  
L. Abdellatif ◽  
B. McConkey ◽  
C. Hamel ◽  
V. Vujanovic

Durum wheat (Triticum durum Desf.) is an important crop in western Canada. In 2005, Arthrinium sacchari was frequently isolated from soil and durum wheat plants of the semi-arid fields of Swift Current, Saskatchewan, Canada (50°16′N, 107°44′W). The susceptibility of durum wheat to damping-off caused by this fungus was evaluated. To our knowledge, this is the first report of A. sacchari in North America (1) and the first mention of its association with durum wheat. DNA was extracted (MoBio Isolation Kit, Carlsbad, CA) from 2-week-old A. sacchari isolates (FBC.3, FBC.45, and FBC.143) grown on PDA. The internal transcribed spacer (ITS) of the rDNA was amplified from each isolate and sequenced (Plant Biotechnology Institute, Saskatoon, SK, Canada) and similarity analyses were performed using the BLAST search algorithm in GenBank. All three sequences (Accession Nos. EF076710, EF076711, and EF076712A) showed 99% similarity with A. sacchari (Accession No. AF393679). An in vitro assay was performed by placing 1-cm2 agar plugs containing mycelia of A. sacchari (FBC.3, FBC.45, and FBC.143) onto surface-sterilized durum. Surface-sterilized seeds inoculated in the same way with Fusarium graminearum or F. avenaceum were used as negative controls, and noninoculated surface-sterilized seeds were used as a positive control. A second in vitro assay involved inoculating the same isolates onto seeds placed in sterilized sandy soil. In both assays, 10 seeds per petri plate and three plates per treatment were used and plates were incubated at 21°C for 1 week in darkness. All experiments were performed twice. On PDA, preemergence damping-off was found in 60% of A. sacchari FBC.3, 55% of A. sacchari FBC.45 and FBC.143, 50% of F. avenaceum, and 58% of F. graminearum inoculated seeds. In sterilized soil, the incidence of preemergence damping-off ranged from 43 to 30%. Subsequent incubation over a period of 3 weeks resulted in 100% postemergence damping-off in A. sacchari FBC.45 and FBC.3 as well as in both Fusarium spp. inoculated controls, 60% postemergence damping-off in A. sacchari FBC.143, and no damping-off in the noninoculated control. Arthrinium and Fusarium spp. were reisolated only from symptomatic plants, satisfying Koch's postulates. In conclusion, durum wheat is highly susceptible to damping-off caused by A. sacchari, showing characteristic dark brown or violet lesions in infected tissues. A. sacchari was previously reported to be present in South America and eastern Asia. In China, it is considered an important mycotoxigenic species (2). Thus, infection of durum wheat crops with A. sacchari could pose a significant threat to North American wheat production. References: (1) D. F. Farr et al. Fungal Databases. Systematic Botany and Mycology Laboratory. Online publication. ARS, USDA, 2006. (2) X. J. Liu et al. Acta Mycol. Sinica 7:221, 1988.


2001 ◽  
Vol 54 ◽  
pp. 84-88 ◽  
Author(s):  
K.L. McLean ◽  
J. Hunt ◽  
A. Stewart

Trichoderma harzianum C52 is an effective biocontrol agent of the onion white rot pathogen Sclerotium cepivorum For this biocontrol agent to be integrated into an existing disease management programme it must be compatible with the fungicides commonly used on onions The sensitivity of T harzianum spores to the field rate of eight fungicides commonly applied to onions was determined in an in vitro assay Results indicate that T harzianum was least sensitive to procymidone and captan and most sensitive to mancozeb tebuconazole and thiram A glasshouse pot trial confirmed that T harzianum was sensitive to mancozeb but tolerant of captan This research indicates that in furrow applications of T harzianum would be compatible with a captan and/or benomyl seed treatment for control of other seedling diseases


Plant Disease ◽  
2002 ◽  
Vol 86 (6) ◽  
pp. 633-638 ◽  
Author(s):  
L. L. R. Marques ◽  
H. Ceri ◽  
G. P. Manfio ◽  
D. M. Reid ◽  
M. E. Olson

Xylella fastidiosa colonizes the xylem of various host plants, causing economically important diseases such as Pierce's disease in grapevine and citrus variegated chlorosis (CVC) in sweet oranges. The aggregative nature of this bacterium has been extensively documented in the plant xylem and the insect's foregut. Structured communities of microbial aggregates enclosed in a self-produced polymeric matrix and attached to a surface are defined as biofilms. In this study, we characterized biofilm formation by X. fastidiosa through the use of a novel in vitro assay for studying biofilm growth in a potential mimic system of what might occur in planta. We used wood, a xylem rich material, as a surface for bacterial attachment and biofilm formation, under shear force. We demonstrated that X. fastidiosa strains isolated from various hosts formed biofilm on wood in this in vitro assay. Different biofilm morphology was detected, which seems to vary according to the strain tested and microenvironmental conditions analyzed. We observed that strains from different hosts could be grouped according to three parameters: biofilm morphology, the ability to form clumps in liquid culture, and the ability to attach to glass surfaces. We hypothesize that biofilm formation is likely a major virulence factor in diseases related to X. fastidiosa, bringing a new perspective for disease treatment.


Akta Agrosia ◽  
2020 ◽  
Vol 23 (1) ◽  
pp. 11-18
Author(s):  
Lukas Soesanto

ABSTRACTProper concentration of soybean flour in the liquid formulation for Trichoderma harzianum T10 growth, its influence to suppress damping-off, and on the growth of cucumber seedlings was investigated. Randomized completely design was used in in vitro test with five treatments and five replicates. The treatments were T. harzianum T10 in Potato Dextrose Broth (control), T. harzianum T10 in soybean fluor of 1, 2, 3 and 4%. Randomiszed block design was used in in planta test with six treatments and five replicates. The treatments consisted of control, T. harzianum T10 in Potato Dextrose Broth, T. harzianum T10 in soybean fluor of 1, 2, 3, and 4%. Variables observed were conidia density, incubation period, disease incidence, area under the disease progress curve, maximum potentially growth, germination persentage, crop height, root fresh weight, shoot fresh weight, and root length. Result of the research showed that the right liquid formulation for T. harzianum T10 growth was the use of soybean fluor with concentration of 2% resulting conidia density as 67,10% compared to PDB. The formulation could suppress the disease incidence, decrease AUDPC value, increase root wet weight, crown wet weight, and root length as 66.67, 66.10, 57.36, 43.81, and 41.81%, respectively, compared to control. Keyword: cucumber, damping-off, liquid formula, soybean flour, Trichoderma harzianum


1968 ◽  
Vol 20 (03/04) ◽  
pp. 384-396 ◽  
Author(s):  
G Zbinden ◽  
S Tomlin

SummaryAn in vitro system is described in which adhesion of blood platelets to washed and tannic acid-treated red cells was assayed quantitatively by microscopic observation. ADP, epinephrine and TAME produced a reversible increase in platelet adhesiveness which was antagonized by AMP. With Evans blue, polyanetholsulfonate, phthalanilide NSC 38280, thrombin and heparin at concentrations above 1-4 u/ml the increase was irreversible. The ADP-induced increase in adhesiveness was inhibited by sodium citrate, EDTA, AMP, ATP and N-ethylmaleimide. EDTA, AMP and the SH-blocker N-ethylmaleimide also reduced spontaneous platelet adhesion to red cells. No significant effects were observed with adenosine, phenprocoumon, 5-HT, phthalanilide NSC 57155, various estrogens, progestogens and fatty acids, acetylsalicylic acid and similarly acting agents, hydroxylamine, glucose and KCN. The method may be useful for the screening of thrombogenic and antithrombotic properties of drugs.


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