scholarly journals Aspergillus terreus obtained from mangrove exhibits antagonistic activities against Pythium aphanidermatum-induced damping-off of cucumber

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7884 ◽  
Author(s):  
Hanaa Al-Shibli ◽  
Sergey Dobretsov ◽  
Abdulrahman Al-Nabhani ◽  
Sajeewa S.N. Maharachchikumbura ◽  
Velazhahan Rethinasamy ◽  
...  
Keyword(s):  
Aspergillus Terreus ◽  
Plant Pathogens ◽  
Dry Weight ◽  
Avicennia Marina ◽  
Pythium Aphanidermatum ◽  
Antagonistic Activity ◽  
Damping Off ◽  
Cucumber Seedlings ◽  
Percent Mortality

A study was conducted to investigate the potential of Aspergillus terreus obtained from Avicennia marina mangrove roots in inhibiting Pythium aphanidermatum and damping-off disease of cucumber. Aspergillus terreus exhibited in vitro inhibition of Pythium aphanidermatum growth. Electron microscope examination revealed that the antagonistic fungal isolate resulted in shrinking and groves in Pythium hypha. When Aspergillus terreus culture filtrate was added to Pythium aphanidermatum, it resulted in a significant increase (by 73%) in electrolyte leakage from Pythium hypha compared to the control, as well as significant reduction (by 71%) in oospore production. The Aspergillus terreus culture was also found to produce a cellulase enzyme, which is suggested to be involved in the antagonism against Pythium aphanidermatum. Adding Aspergillus terreus to soil infested with Pythium aphanidermatum significantly reduced percent mortality in cucumber seedlings by 70%. Aspergillus terreus, when applied alone on cucumber seedlings, did not show any suppressive effects on cucumber growth (length and fresh and dry weight). This appears to be the first report of isolation from mangrove of Aspergillus terreus with antagonistic activity against Pythium aphanidermatum-induced damping-off of cucumber. The study indicates that fungal isolates obtained from marine environments may serve as potential biocontrol agents against some plant pathogens.

scholarly journals In vitro Evaluation of Bacterial Endophytes for Biocontrol of Pythium aphanidermatum and Plant Growth Promotion in Setaria italica L. Grown in Seedling Trays

2019 ◽  
pp. 1-14 ◽  
Author(s):  
M. Raveendra Reddy ◽  
M. K. Shivaprakash ◽  
S. Adithya
Keyword(s):  
Growth Promotion ◽  
Disease Incidence ◽  
Foxtail Millet ◽  
Dry Weight ◽  
Pythium Aphanidermatum ◽  
Antagonistic Activity ◽  
Setaria Italica ◽  
Bacterial Endophytes ◽  
Causal Organism

An investigation study was carried to test the ability of endophytic bacteria isolated from small millets as a biocontrol agent against the fungal pathogen Pythium aphanidermatum, the causal organism of sheath blight in foxtail millet (Setaria italica L.) grown in seedling trays under greenhouse conditions. In total twelve bacterial endophytes were isolated out of which six isolates produced β -1, 3 glucanases, 11 isolates produced chitinases and 12 isolates produced siderophores under in-vitro conditions. All these bacterial endophytic isolates inhibited mycelial growth of Pythium aphanidermatum in plate assay and liquid culture and the highest percent inhibition of mycelium was recorded in KMS5 (44.44%) followed by KMS1 (38.89%). In seedling trays, BMR7 and KMS5 (81.66%) had recorded the highest percent germination followed by KMS1 (79.62%) and KMS1 and KMS5 took 10.85 and 10.55 days respectively for 50% seed germination compared to control (13.50 days) which was treated with pathogen alone. Lowest pre-emergence disease incidence was noticed in KMS5 (14.03%) followed by KMS1 (16.18%) whereas T1 (Control) recorded maximum pre-emergence disease incidence (39.82%) was observed. Least post-emergence disease incidence (11.36) and biocontrol efficacy (68.74%) was recorded with KMS5. Apart from showing antagonistic activity, KMS5 had recorded a significantly higher seedling vigor index (2712.97), root length (18.12 cm), shoot length (15.10 cm), root dry weight (0.158 g) and shoot dry weight (0.76 g) compared to other bacterial endophytic isolates.

Effect of the endophytic plant growth promoting Enterobacter ludwigii EB4B on tomato growth

2020 ◽  
Vol 13 (2) ◽  
pp. 54-65 ◽  
Author(s):  
M.E.A. Bendaha ◽  
H.A. Belaouni
Keyword(s):  
Root Length ◽  
Biocontrol Agent ◽  
Growth Promotion ◽  
Dry Weight ◽  
Antagonistic Activity ◽  
Rrna Gene ◽  
Plant Growth Promoting ◽  
Enterobacter Ludwigii ◽  
Tomato Growth

SummaryThis study aims to develop a biocontrol agent against Fusarium oxysporum f.sp. radicis-lycopersici (FORL) in tomato. For this, a set of 23 bacterial endophytic isolates has been screened for their ability to inhibit in vitro the growth of FORL using the dual plate assay. Three isolates with the most sound antagonistic activity to FORL have been qualitatively screened for siderophore production, phosphates solubilization and indolic acetic acid (IAA) synthesis as growth promotion traits. Antagonistic values of the three candidates against FORL were respectively: 51.51 % (EB4B), 51.18 % (EB22K) and 41.40 % (EB2A). Based on 16S rRNA gene sequence analysis, the isolates EB4B and EB22K were closely related to Enterobacter ludwigii EN-119, while the strain EB2A has been assigned to Leclercia adecarboxylata NBRC 102595. The promotion of tomato growth has been assessed in vitro using the strains EB2A, EB4B and EB22K in presence of the phytopathogen FORL. The treatments with the selected isolates increased significantly the root length and dry weight. Best results were observed in isolate EB4B in terms of growth promotion in the absence of FORL, improving 326.60 % of the root length and 142.70 % of plant dry weight if compared with untreated controls. In the presence of FORL, the strain EB4B improved both root length (180.81 %) and plant dry weight (202.15 %). These results encourage further characterization of the observed beneficial effect of Enterobacter sp. EB4B for a possible use as biofertilizer and biocontrol agent against FORL.

scholarly journals Myco-Suppression Analysis of Soybean (Glycine max) Damping-Off Caused by Pythium aphanidermatum

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 788
Author(s):  
Shaban R. M. Sayed ◽  
Shaimaa A. M. Abdelmohsen ◽  
Hani M. A. Abdelzaher ◽  
Mohammed A. Elnaghy ◽  
Ashraf A. Mostafa ◽  
...  
Keyword(s):  
Glycine Max ◽  
Biocontrol Agent ◽  
Lateral Roots ◽  
Dry Weight ◽  
Pythium Aphanidermatum ◽  
Damping Off ◽  
Pythium Oligandrum ◽  
Rdna Its ◽  
Half Strength

The role of Pythium oligandrum as a biocontrol agent against Pythium aphanidermatum was investigated to avoid the harmful impacts of fungicides. Three isolates of P. oligandrum (MS15, MS19, and MS31) were assessed facing the plant pathogenic P. aphanidermatum the causal agent of Glycine max damping-off. The tested Pythium species were recognized according to their cultural and microscopic characterizations. The identification was confirmed through sequencing of rDNA-ITS regions including the 5.8 S rDNA. The biocontrol agent, P. oligandrum, isolates decreased the mycelial growth of the pathogenic P. aphanidermatum with 71.3%, 67.1%, and 68.7% through mycoparasitism on CMA plates. While the half-strength millipore sterilized filtrates of P. oligandrum isolates degrade the pathogenic mycelial linear growth by 34.1%, 32.5%, and 31.7%, and reduce the mycelial dry weight of the pathogenic P. aphanidermatum by 40.1%, 37.4%, and 36.8%, respectively. Scanning electron microscopy (SEM) of the most effective antagonistic P. oligandrum isolate (MS15) interaction showed coiling, haustorial parts of P. oligandrum to P. aphanidermatum hyphae. Furthermore, P. oligandrum isolates were proven to enhance the germination of Glycine max seedling to 93.3% in damping-off infection using agar pots and promote germination of up to 80% during soil pot assay. On the other hand, P. oligandrum isolates increase the shoot, root lengths, and the number of lateral roots.

scholarly journals Microbial Origin of Aquaponic Water Suppressiveness against Pythium aphanidermatum Lettuce Root Rot Disease

2020 ◽  
Vol 8 (11) ◽  
pp. 1683
Author(s):  
Gilles Stouvenakers ◽  
Sébastien Massart ◽  
Pierre Depireux ◽  
M. Haïssam Jijakli
Keyword(s):  
Water Reuse ◽  
Plant Pathogens ◽  
Control Plant ◽  
Pythium Aphanidermatum ◽  
Suppressive Effect ◽  
Inhibitory Effect ◽  
Antagonistic Effect ◽  
Mobile Form ◽  
Root Microbiota

Aquaponic systems are an integrated way to produce fish and plants together with mutual benefits. Fish provide nutrients to plants on the one side, and plant nutrients uptake allow water reuse for fish on the other side. In this kind of system, the use of phytosanitary treatments to control plant pathogens is sensitive because of the risk of toxicity for fish present in the same water loop, especially coupled aquaponics. Among plant pathogens, Pythium aphanidermatum is a most problematic microorganism due to the Oomycete’s capacity to produce mobile form of dispersion (zoospores) in the recirculated water. Therefore, this study aimed at elucidating the potential antagonistic capacity of aquaponic water against P. aphanidermatum diseases. It was shown that aquaponic water presented an inhibitory effect on P. aphanidermatum mycelial growth in in vitro conditions. The same result was observed when lettuce plants growing in aquaponic water were inoculated by the same plant pathogen. Aquaponic lettuce was then compared to lettuce grown in hydroponic water or complemented aquaponic water (aquaponic water plus mineral nutrients). The disease was suppressed in the presence of aquaponic water, contrary to lettuce grown in hydroponic water or complemented aquaponic water. Root microbiota were analyzed by 16S rDNA and ITS Illumina sequencing to determine the cause of this aquaponic suppressive action. It was determined that the diversity and the composition of the root microbiota were significantly correlated with the suppressive effect of aquaponic water. Several taxa identified by metabarcoding were suspected to be involved in this effect. Moreover, few of these microorganisms, at the genus level, are known to have an antagonistic effect against P. aphanidermatum. These innovative results indicate that aquaponic water could be an interesting and novel source of antagonistic agents adapted to control P. aphanidermatum diseases in soilless culture.

Trichoderma cyanodichotomus sp. nov., a new soil-inhabiting species with a potential for biological control

2018 ◽  
Vol 64 (12) ◽  
pp. 1020-1029
Author(s):  
Jishun Li ◽  
Yuanzheng Wu ◽  
Kai Chen ◽  
Yilian Wang ◽  
Jindong Hu ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Plant Pathogens ◽  
Elongation Factor ◽  
Antagonistic Activity ◽  
Hunan Province ◽  
Dual Culture ◽  
Trichoderma Species ◽  
Biodiversity Survey ◽  
Close Relatives

During a biodiversity survey of Trichoderma (Ascomycota, Hypocreales, Hypocreaceae) in coastal and lake wetlands of China, a new species, Trichoderma cyanodichotomus, was isolated from Dongting Lake wetland of Hunan province. The strain TW21990-1 was characterized as having two types of conidia and producing a distinct blue–green pigment on potato dextrose agar and cornmeal dextrose agar. The taxonomic position was analyzed using three molecular markers, internal transcribed spacer rDNA, translation elongation factor 1-alpha, and RNA polymerase II subunit B, revealing less than 95.0% homology with all known Trichoderma species. The combined phylogenetic tree further identified T. cyanodichotomus as an independent subgroup belonging to Section Pachybasium, with no close relatives. In vitro antagonistic activity by dual-culture assay exhibited broad inhibition against various plant pathogens, including Botryosphaeria dothidea, Pythium aphanidermatum, Rhizoctonia solani, and Verticillium dahliae. In addition, TW21990-1 demonstrated moderate hydrolase activity of cellulase, chitinase, β-1,3-glucanase, and protease, which might be involved in mycoparasitism. Greenhouse experiments showed strong biocontrol effects against tomato damping-off incited by P. aphanidermatum, together with increased seedling height and weight gain. The identification of T. cyanodichotomus will provide useful information for sufficient utilization of fungal resources.

scholarly journals Efficacy of Mahapancha Gavya (MPG) in controlling damping-off in tomato caused by Pythium aphanidermatum

1970 ◽  
Vol 35 (1) ◽  
pp. 11-16
Author(s):  
Rakesh Kumar ◽  
Indra Hooda ◽  
SS Karwasra
Keyword(s):  
Disease Control ◽  
Integrated Control ◽  
Trichoderma Viride ◽  
Pythium Aphanidermatum ◽  
Integrated Treatment ◽  
Damping Off ◽  
Complete Control ◽  
Tomato Seedlings ◽  
Neem Leaf Extract

Maha Pancha Gavya (MPG), a concoction made from five cow products was tested for its toxicity against Pythium aphanidermatum (Edson) Fitz. and its antagonists at 5, 10, 25, and 50% concentration in in vitro to find out if it can be used in integration for the control of damping-off in tomato in nursery beds. MPG was very effective inihibiting the growth of P. aphanidermatum. At the highest concentration, the growth of the pathogen was negligible. Isolates of Trichoderma viride, T harzianum, and T. virens were also sensitive to MPG at all the concentrations. Their radial growth decreased, but it was fluffy in nature and sporulated profusely. MPG was not toxic against two bacterial antagonists i.e., Bacillus subtilis and Pseudomonas fluorescens. Soil application of 10% MPG to nursery beds improved seedling stand and gave upto 48.27% tlisease control, which was more than that given by individual antagonists. However, MPG improved disease control efficacy of all the antagonists when it was used in combination with them. Integrated treatment with MPG and B. subtilis gave maximum disease control (65.33%). MPG enhanced seedling growth and it was more in combination with T. viride and B. subtilis. MPG in integration with neem cake and neem leaf extract gave complete control of damping-off and maxium increase in height of the tomato seedlings. Keywords: Maha Panch Gavya (MPG); Trichoderma; Pythium aphanidermatum; integrated control; neem products; tomato; damping-off. DOI: 10.3329/bjar.v35i1.5862Bangladesh J. Agril. Res. 35(1) : 11-16, March 2010

Phaeotheca dimorphospora increases Trichoderma harzianum density in soil and suppresses red pine damping-off caused by Cylindrocladium scoparium

1995 ◽  
Vol 73 (5) ◽  
pp. 693-700 ◽  
Author(s):  
D. Yang ◽  
L. Bernier ◽  
M. Dessureault
Keyword(s):  
Biological Control ◽  
Trichoderma Harzianum ◽  
Plant Pathogens ◽  
Disease Incidence ◽  
Pinus Resinosa ◽  
Red Pine ◽  
Damping Off ◽  
Fungal Antagonist ◽  
Petri Dishes

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.

scholarly journals Diversity of biocontrol agents, isolated from several sources, inhibitory to several fungal plant pathogens

2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Yan Ramona ◽  
IDA BAGUS GEDE DARMAYASA ◽  
ANAK AGUNG NGURAH NARA KUSUMA ◽  
Martin Line
Keyword(s):  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Antagonistic Activity ◽  
Significant Inhibition ◽  
Biocontrol Agents ◽  
Dual Culture ◽  
Rdna Sequences ◽  
Fungal Plant Pathogens ◽  
Mature Compost

Abstract. Ramona Y, Darmayasa IBG, Kusuma AANN, Line MA. 2021. Diversity of biocontrol agents, isolated from several sources, inhibitory to several fungal plant pathogens. Biodiversitas 22: 298-303. This study investigated the inhibitory potential of diversity of antagonist bacteria residing in the rhizosphere zone and mature compost to counter fungal plant pathogens. Soils collected from rhizosphere of lettuce farms in Bali-Indonesia and Tasmania-Australia, mature compost, commercial biocontrol (Dipel®), and laboratory contaminants with significant inhibition against tested fungal pathogens were used as sources of antagonist bacteria. These antagonists were isolated by applying dilution and spread method on trypticase soya agar (TSA) or potato dextrose agar (PDA), and their ability to inhibit Sclerotinia minor, Sclerotinia sclerotiorum, Fusarium spp., and Rhizoctonia solani was assessed in dual culture assays. The results showed that 67 out of more than 100 isolates had antagonistic activity in vitro against at least one of tested fungal pathogens. In the preliminary identification, Bacillus spp. or Pseudomonas spp. were found to be pre-dominant isolates. Following screening studies in a non-replicated glasshouse experiment against S. minor and S. sclerotiorum, 8 of the most promising isolates were further identified using molecular methods based on their 16s rDNA sequences aligned with those deposited at the GeneBank. These 8 isolates were identified as Pseudomonas corrugata, Bacillus megaterium, Bacillus polymyxa, Bacillus mojavensis, Bacillus pumilus, Bacillus thuringiensis, Exiguobacterium acetylicum, and Chryseobacterium indologenes.

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
Keyword(s):  
Secondary Metabolites ◽  
Trichoderma Harzianum ◽  
Disease Incidence ◽  
In Vitro Assay ◽  
Cucumber Seedling ◽  
Damping Off ◽  
In Planta ◽  
Vitro Assay ◽  
Cucumber Seedlings

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.

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