Biological Control of Pythium Damping –off in Seedlings with Streptomyces Sp.

Damping-off is one of the severe diseases caused by soil-borne pathogens notably Pythium sp. the causative agent of this infection in raising tree saplings in forest nurseries. Biological control is an eco-friendly approach in disease management compared to chemical fungicides which in turn affects the soil environment. Biocontrol of Pythium sp. has been emphasized in vegetable nurseries than forest nurseries. The present research work is focused on identification of effective antagonistic organism from forest nursery soils against Pythium aphanidermatum. Bacteria were isolated from various forest soils collected from Boluvampati, Sirumugai and Mettupalayam forest nurseries in Coimbatore district and soil samples were screened for antifungal activity against Pythium aphanidermatum by dual culture technique. Among 245 bacterial isolates, one isolate KUMB1.1 exhibited clear zone of inhibition of 1cm and it was identified by 16S rDNA sequencing as Streptomyces sp. Solvent extraction was performed to isolate an active compound using ethyl acetate, dichloromethane, n-butanol, hexane and chloroform in the ratio 1:1. The antifungal activity of compound was performed by well plate method against Pythium sp. and nbutanol extract exhibited zone of inhibition. The antifungal activity of Streptomyces sp. was tested in a model plant Solanum lycopersicum (Tomato) seeds raised in Pythium aphanidermatum infested soils in seed trays under in vitro conditions. Preemergence and post-emergence disease incidences were observed, and the results exhibited promising efficacy of Streptomyces sp. against the fungal pathogen Pythium aphanidermatum. Seedbed study was carried out in Gmelina arborea seeds, where the seeds are treated with Streptomyces culture broth. In which seed treatment shows 43% increase in germination compared with control.

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Postinfection Biological Control of Oomycete Pathogens of Pea by Burkholderia cepacia AMMDR1

Phytopathology ◽

10.1094/phyto.2001.91.4.383 ◽

2001 ◽

Vol 91 (4) ◽

pp. 383-391 ◽

Cited By ~ 24

Author(s):

K. Heungens ◽

J. L. Parke

Keyword(s):

Biological Control ◽

Burkholderia Cepacia ◽

Antibiotic Production ◽

Pythium Aphanidermatum ◽

Life Cycles ◽

Infection Process ◽

Lesion Length ◽

Aphanomyces Euteiches ◽

Damping Off ◽

Tn5 Mutant

Burkholderia cepacia AMMDR1 is a biocontrol agent that reduces Pythium damping-off and Aphanomyces root rot severity on peas in the field. We studied the effect of B. cepacia AMMDR1 on post-infection stages in the life cycles of these pathogens, including mycelial colonization of the host, production of oogonia, and production of secondary zoospore inoculum. We used Burkholderia cepacia 1324, a seed and rootcolonizing but antibiosis-deficient Tn5 mutant of B. cepacia AMMDR1, to study mechanisms of biological control other than antibiosis. B. cepacia AMMDR1 significantly reduced Pythium aphanidermatum postinfection colonization and damping-off of pea seeds, even when the bacteria were applied 12 h after zoospore inoculation. B. cepacia AMMDR1 also significantly reduced colonization of taproots by Aphanomyces euteiches mycelium, but only when the bacteria were applied at high population densities at the site of zoospore inoculation. The antibiosisdeficient mutant, B. cepacia 1324, had no effect on mycelial colonization of seeds or roots by Pythium aphanidermatum nor A. euteiches, suggesting that antibiosis is the primary mechanism of biological control. B. cepacia AMMDR1, but not B. cepacia 1324, reduced production of A. euteiches oogonia. This effect occurred even when the population size of B. cepacia AMMDR1 was too small to cause a reduction in lesion length early on in the infection process and may result from in situ antibiotic production. B. cepacia AMMDR1 had no effect on the production of secondary zoospores of A. euteiches from infected roots. The main effects of B. cepacia AMMDR1 on postinfection stages in the life cycles of these pathogens therefore were reductions in mycelial colonization by Pythium aphanidermatum and in formation of oogonia by A. euteiches. No mechanism other than antibiosis could be identified.

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Toward the Quantification of Confrontation (Dual Culture) Test: A Case Study on the Biological control of Pythium aphanidermatum with Trichoderma asperelloides

Journal of Fertilizers & Pesticides ◽

10.4172/2155-6202.1000137 ◽

2013 ◽

Vol 04 (02) ◽

Cited By ~ 5

Author(s):

Babak S Pakdaman

Keyword(s):

Biological Control ◽

Pythium Aphanidermatum ◽

Dual Culture ◽

Culture Test

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Biological control of damping-off of tomato caused by Pythium aphanidermatum by using native antagonistic rhizobacteria isolated from Omani soil

Journal of Plant Pathology ◽

10.1007/s42161-018-0184-x ◽

2018 ◽

Vol 101 (2) ◽

pp. 315-322 ◽

Cited By ~ 9

Author(s):

Hanan S. Al-Hussini ◽

Amna Y. Al-Rawahi ◽

Abdullah A. Al-Marhoon ◽

Shurooq A. Al-Abri ◽

Issa H. Al-Mahmooli ◽

...

Keyword(s):

Biological Control ◽

Pythium Aphanidermatum ◽

Damping Off

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Biological control of Pythium aphanidermatum-induced cucumber and radish damping-off by an endophytic fungus, Cladosporium omanense isolate 31R

Biocontrol Science and Technology ◽

10.1080/09583157.2020.1844148 ◽

2020 ◽

pp. 1-17

Author(s):

Boshra A. Halo ◽

Rashid A. Al-Yahyai ◽

Abdullah M. Al-Sadi

Keyword(s):

Biological Control ◽

Endophytic Fungus ◽

Pythium Aphanidermatum ◽

Damping Off

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Biological Control of Pear Valsa Canker Caused by Valsa pyri Using Penicillium citrinum

Horticulturae ◽

10.3390/horticulturae7070198 ◽

2021 ◽

Vol 7 (7) ◽

pp. 198

Author(s):

Hongbo Yuan ◽

Bingke Shi ◽

Tianxiang Huang ◽

Zengqiang Zhou ◽

Li Wang ◽

...

Keyword(s):

Biological Control ◽

Antifungal Activity ◽

Biological Control Agent ◽

Disease Incidence ◽

Morphological Characteristics ◽

Control Agent ◽

Penicillium Citrinum ◽

Lesion Length ◽

Dual Culture ◽

Valsa Canker

Valsa canker caused by Valsa pyri is one of the most destructive diseases of commercial pear. For the present analysis, 29 different endophytic fungal strains were isolated from the branches of a healthy pear tree. In dual culture assays, strain ZZ1 exhibited robust antifungal activity against all tested pathogens including Valsa pyri. Microscopic analyses suggested that following co-culture with ZZ1, the hyphae of V. pyri were ragged, thin, and ruptured. ZZ1 also induced significant decreases in lesion length and disease incidence on detached pear branches inoculated with V. pyri. ZZ1 isolate-derived culture filtrates also exhibited antifungal activity against V. pyri, decreasing mycelial growth and conidium germination and inhibiting V. pyri-associated lesion development on pear branches. These results suggest that the ZZ1 isolate has the potential for use as a biological control agent against V. pyri. The strain was further identified as Penicillium citrinum based on its morphological characteristics and molecular analyses. Overall, these data highlight a potentially valuable new biocontrol resource for combating pear Valsa canker.

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The biological control of seed-borne Alternaria brassicicola of cruciferous plants with a powdery preparation of Streptomyces sp.

Agricultural and Food Science ◽

10.23986/afsci.72264 ◽

1987 ◽

Vol 59 (3) ◽

pp. 199-208 ◽

Cited By ~ 2

Author(s):

Risto Tahvonen ◽

Hanna Avikainen

Keyword(s):

Biological Control ◽

Brassica Species ◽

Fine Sand ◽

Alternaria Brassicicola ◽

Damping Off ◽

Streptomyces Sp ◽

Seed Dressing ◽

Dry Conditions ◽

Cruciferous Plants ◽

Different Origin

The effectiveness of a powdery preparation of a Streptomyces sp. isolate as a seed dressing agent against seed-borne Alternaria brassicicola on different Brassica species was investigated in the study. The preparation was made by freeze-drying and milling the biomass produced in a fermentor into a form suitable for use as a dusting agent. Seed dressing was 80—90 % successful in controlling damping-off from seeds artificially infected with A. brassicicola. The effectiveness of dressing remained unchanged on seeds stored under dry conditions for 5—6 weeks, but subsequently decreased slowly and was ca. 50 % six months after dusting. Streptomyces dressing controlled, in a manner comparable to chemical dressing with thiram, damping-off caused by Alternaria fungi on seedlings which were grown from commercial seed lots of different origin. The results of biological control of damping-off did not vary in the peat lots of different origin whose natural disease suppressivity varied considerably. The control result was the same or better than chemical dressing with thiram. The acidity of the substrate (pH 4.8—8.6) had no effect on the effectiveness of biological control. The results obtained against Alternaria damping-off were the same in other substrates clay, fine sand and mull as in peat.

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Efficacy of native antagonistic rhizobacteria in the biological control of Pythium aphanidermatum-induced damping-off of cucumber in Oman

Journal of Plant Pathology ◽

10.1007/s42161-019-00438-9 ◽

2019 ◽

Vol 102 (2) ◽

pp. 305-310 ◽

Cited By ~ 3

Author(s):

Dhuha Sulaiman Salim Al-Daghari ◽

Shurooq Abdullah Al-Abri ◽

Issa Hashil Al-Mahmooli ◽

Abdullah Mohammed Al-Sadi ◽

Rethinasamy Velazhahan

Keyword(s):

Biological Control ◽

Pythium Aphanidermatum ◽

Damping Off

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Microbial communities in roots ofPinus sylvestrisseedlings with damping-off symptoms in two forest nurseries as determined by ITS1/2 rDNA sequencing

Forest Pathology ◽

10.1111/j.1439-0329.2008.00583.x ◽

2009 ◽

Vol 39 (4) ◽

pp. 239-248 ◽

Cited By ~ 7

Author(s):

H. Kwaśna ◽

G. L. Bateman

Keyword(s):

Microbial Communities ◽

Damping Off ◽

Rdna Sequencing ◽

Forest Nurseries

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A comparison between Pseudomonas aureofaciens (chlororaphis) and P. fluorescens in biological control of cotton seedling damping-off disease

Journal of Plant Protection Research ◽

10.2478/jppr-2014-0019 ◽

2014 ◽

Vol 54 (2) ◽

pp. 115-121

Author(s):

Samavat Samaneh ◽

Asghar Heydari ◽

Hamid Reza Zamanizadeh ◽

Saeed Rezaee ◽

Ali Alizadeh Aliabadi

Keyword(s):

Biological Control ◽

Greenhouse Experiment ◽

Plant Diseases ◽

Dual Culture ◽

Damping Off ◽

Wild Type ◽

Cotton Seedling ◽

Pseudomonas Aureofaciens ◽

Volatile Metabolites ◽

Bacterial Antagonists

Abstract Due to the importance of the biological control of plant diseases, testing and introducing new biocontrol-active microorganisms is a major concern among plant pathologists. The causal agent of cotton seedling damping-off disease is Rhizoctonia solani. In this regard, we tried to investigate the antagonistic activities of Pseudomonas aureofaciens (chlororaphis) 30–84 (phenazine producing wild type and non-phenazine producing mutant) strains on R. solani, in comparison with some isolates of P. fluorescent under both in vitro (laboratory) and in vivo (greenhouse) conditions. In the laboratory experiment, the inhibitory effects of all the bacteria, on the growth of R. solani, were evaluated using the dual culture procedure. Results showed that five isolates of P. fluorescent along with both strains of P. aureofaciens significantly inhibited the growth of R. solani. Effective bacterial antagonists were then evaluated in a greenhouse experiment where cotton seeds were coated with their suspensions and were sown in pasteurised field-soil. The soil had been pre-inoculated with a virulent isolate of R. solani. The efficacy of the bacterial antagonists was evaluated by counting the number of surviving seedlings in different treatments, at 15 and 60 days after sowing, for determining pre- and post-emergence damping-off incidence. According to the results of the greenhouse experiment, at both intervals, two isolates of P. fluorescens along with both strains of P. aureofaciens caused significant increases in the number of healthy seedlings, in comparison with the untreated control, and a commonly used fungicide (carboxin-thiram). The efficacy of phenazine producing a wild type strain of P. aureofaciens was higher than its non-phenazine producing mutant, indicating that phenazine plays an important role in the antagonistic activity of P. aureofaciens. Effective bacterial antagonists were then studied for their antagonistic mechanisms. The results showed that all four bacteria employed different mechanisms. The bacteria produced siderophore, and volatile metabolites and non-volatile metabolites, in their antagonistic activities. The results of this study suggest that P. auerofaciens may be a new biocontrol agent for controlling cotton seedling mortality disease.

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