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

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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Evaluation of fungal isolates for the inhibition of vegetative growth of Venturis inaequalis

Canadian Journal of Botany ◽

10.1139/b97-070 ◽

1997 ◽

Vol 75 (4) ◽

pp. 626-631 ◽

Cited By ~ 8

Author(s):

A. Ouimet ◽

O. Carisse ◽

P. Neumann

Keyword(s):

Biological Control ◽

Vegetative Growth ◽

Biological Control Agent ◽

Venturia Inaequalis ◽

Apple Scab ◽

Inhibitory Effect ◽

Control Agent ◽

Dual Culture ◽

Inhibitory Effects ◽

Aureobasidium Sp

As a part of a broader study on biological control of apple scab, caused by Venturia inaequalis, a collection of 183 microorganisms originating from apple leaf litter was evaluated for their inhibitory effects on the vegetative growth of V. inaequalis. In a first screening, based on dual culture, 31 isolates (17%) showed inhibition. From these isolates, 11 fungi were selected for quantitative evaluation based on the presence of a distinct zone of inhibition. The selected fungi were evaluated again, in a more precise test, which indicated that isolates P164A (Ophiostoma sp.), P66A (Chaetophoma sp.), P26A (Aureobasidium sp.), P59A (Phoma sp.), and P28A (unidentified) inhibited 95.3, 88.9, 85.8, 80.7, and 80.1% of mycelial growth, respectively. Inhibition by the most effective fungus (Ophiostoma sp.) lasted for more than 58 days. A test using culture filtrates, incubated over time, was carried out to determine whether the living fungus was a prerequisite for inhibition. The inhibitory effect of metabolites secreted by the selected fungi was less than 5%. This study revealed the potential of at least five fungi that could be considered in the development of a biological control agent against V. inaequalis. Key words: antifungal inhibition, apple scab, biological control.

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Cladobotryum mycophilum as Potential Biocontrol Agent

Agronomy ◽

10.3390/agronomy9120891 ◽

2019 ◽

Vol 9 (12) ◽

pp. 891

Author(s):

Mila Santos ◽

Fernando Diánez ◽

Alejandro Moreno-Gavíra ◽

Brenda Sánchez-Montesinos ◽

Francisco J. Gea

Keyword(s):

Biological Control ◽

Fusarium Oxysporum ◽

Biocontrol Agent ◽

Biological Control Agent ◽

Control Agent ◽

Phytopathogenic Fungi ◽

Antagonistic Activity ◽

Dual Culture ◽

Potential Biocontrol Agent

A study was conducted to explore the efficacy of potential biocontrol agent Cladobotryum mycophilum against different phytopathogenic fungi. The growth rates of 24 isolates of C. mycophilum were determined, and their antagonistic activity was analysed in vitro and in vivo against Botrytis cinerea, Fusarium oxysporum f. sp. radicis-lycopersici, Fusarium oxysporum f.sp. cucumerinum, Fusarium solani, Phytophthora parasitica, Phytophthora capsici, Pythium aphanidermatum and Mycosphaerella melonis. Most isolates grow rapidly, reaching the opposite end of the Petri dish within 72–96 h. Under dual-culture assays, C. mycophilum showed antagonistic activity in vitro against all phytopathogenic fungi tested, with mycelial growth inhibition ranging from 30 to 90% against all the different phytopathogens tested. Similarly, of all the selected isolates, CL60A, CL17A and CL18A significantly (p < 0.05) reduced the disease incidence and severity in the plant assays compared to the controls for the different pathosystems studied. Based on these results, we conclude that C. mycophilum can be considered as a potential biological control agent in agriculture. This is the first study of Cladobotryum mycophilum as a biological control agent for different diseases caused by highly relevant phytopathogens in horticulture.

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Biological Control of Fungal Diseases by Trichoderma aggressivum f. europaeum and Its Compatibility with Fungicides

Journal of Fungi ◽

10.3390/jof7080598 ◽

2021 ◽

Vol 7 (8) ◽

pp. 598

Author(s):

Brenda Sánchez-Montesinos ◽

Mila Santos ◽

Alejandro Moreno-Gavíra ◽

Teresa Marín-Rodulfo ◽

Francisco J. Gea ◽

...

Keyword(s):

Biological Control ◽

Growth Rates ◽

Biological Control Agent ◽

Disease Incidence ◽

Management Strategies ◽

High Growth ◽

Control Agent ◽

Antagonistic Activity ◽

La Mancha

Our purpose was to evaluate the ability of Trichoderma aggressivum f. europaeum as a biological control agent against diseases from fungal phytopathogens. Twelve isolates of T. aggressivum f. europaeum were obtained from several substrates used for Agaricus bisporus cultivation from farms in Castilla-La Mancha (Spain). Growth rates of the 12 isolates were determined, and their antagonistic activity was analysed in vitro against Botrytis cinerea, Sclerotinia sclerotiorum, Fusarium solani f. cucurbitae, Pythium aphanidermatum, Rhizoctonia solani, and Mycosphaerella melonis, and all isolates had high growth rates. T. aggressivum f. europaeum showed high antagonistic activity for different phytopathogens, greater than 80%, except for P. aphanidermatum at approximately 65%. The most effective isolate, T. aggressivum f. europaeum TAET1, inhibited B. cinerea, S. sclerotiorum, and M. melonis growth by 100% in detached leaves assay and inhibited germination of S. sclerotiorum sclerotia. Disease incidence and severity in plant assays for pathosystems ranged from 22% for F. solani to 80% for M. melonis. This isolate reduced the incidence of Podosphaera xanthii in zucchini leaves by 66.78%. The high compatibility by this isolate with fungicides could allow its use in combination with different pest management strategies. Based on the results, T. aggressivum f. europaeum TAET1 should be considered for studies in commercial greenhouses as a biological control agent.

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Evaluation of Strategies and Implementation of Biological Control of Fire Blight

10.32747/1993.7568106.bard ◽

1993 ◽

Author(s):

Steven E. Lindow ◽

Shulamit Manulis ◽

Dan Zutra ◽

Dan Gaash

Keyword(s):

Biological Control ◽

Fire Blight ◽

Biological Control Agent ◽

Disease Incidence ◽

Freezing Temperature ◽

Plasmid Profile ◽

Control Agent ◽

Bacterial Strains ◽

Antagonistic Microorganisms ◽

Population Sizes

The main objective of this study was to develop data that would facilitate a consistently effective method of biological control of fire blight disease to be developed and to enable its implementation for disease control by ensuring its compatibility with variations in the biological, environmental, and chemical conditions present in pear orchards. As considerable information on the pathogen and biological control of fire blight was already gathered from studies in California and elsewhere, an emphasis was placed on investigating the genetics and ecology of Erwinia amylovora, the causal agent of fire blight in Israel. Studies of plasmid profile, virulence on several host, serological characteristics, as well as DNA fingerprints with selected primers all revealed E. amylovora strains in Israel to be homogeneous. Strains did vary in their resistance to streptomycin, with those from more northern locations being resistant while those in the southern costal plain were all sensitive to streptomycin. Resistance appeared to be conferred by chromosomal mutations as in streptomycin-resistant strains in California. The biological control agent Pseudomonas fluorescens strain A506 colonized flowers of both the Costia and Spodona pear cultivars in Israel as well as Bartlett pear in California. Flowers that were open at the time of spray inoculation of trees subsequently harbored from 105 to 107 cells of strain A506 per flower, while those that opened subsequent to spraying developed population sizes of about 105 cells/flower within 5 days. The incidence of fire blight infections were reduced about 3-fold in several trials in which moderate amounts of disease occurred in the plot areas; this degree of biological control is similar to that observed in California and elsewhere. On two occasions warm and moist weather that favored disease led to epidemics in which nearly all flowers became infected and which was so severe that neither P. fluorescens strain A506 nor chemical bactericides reduced disease incidence. A novel method for identifying antagonistic microorganisms for biological control of fire blight and other diseases was developed. A bacterial ice nucleation gene was introduced into E. amylovora to confer an Ice+ phenotype and the population sizes of this modified pathogen on flowers that had been pre-treated with potential control agents was estimated by measuring the freezing temperature of colonized flowers. Antagonistic strains that prevented the growth of E. amylovora in flowers were readily detected as those in which flowers froze at a low temperature. The method is both rapid and unbiased and several bacterial strains with substantial biological control potential have been identified using this method.

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Uji Antagonisme Bacillus cereus terhadap Rhizoctonia solani dan Sclerotium rolfsii

Buletin Tanaman Tembakau Serat & Minyak Industri ◽

10.21082/bultas.v7n1.2015.1-8 ◽

2016 ◽

Vol 7 (1) ◽

pp. 1

Author(s):

Nurul Hidayah ◽

Titiek Yulianti

Keyword(s):

Biological Control ◽

Growth Rate ◽

Rhizoctonia Solani ◽

Biological Control Agent ◽

Sclerotium Rolfsii ◽

Control Agent ◽

Dual Culture ◽

Bacillus Sp ◽

Unfavorable Condition

Jamur Rhizoctonia solani dan Sclerotium rolfsii merupakan kelompok jamur steril (tidak menghasilkan spora) tetapi dapat menghasilkan sklerosia sebagai sumber inokulum primer, dan struktur istirahat jamur yang dapat bertahan selama beberapa tahun di dalam tanah saat kondisi lingkungan kurang menguntungkan. Penggunaan fungisida, fumigasi, dan solarisasi tanah telah digunakan untuk mengendalikan kedua jamur tersebut, namun hasil yang diperoleh masih beragam. Pengendalian hayati dengan menggunakan bakteri Bacillus sp. yang merupakan salah satu kelompok agens hayati patogen diketahui memberikan hasil yang baik pada beberapa tanaman. Penelitian yang bertujuan menguji potensi B. cereus dalam menghambat pertumbuhan jamur R. solani dan S. rolfsii secara in vitro dilaksanakan di Laboratorium Fitopatologi Balittas dengan menggunakan metode dual culture pada media potato dextrose agar (PDA). Miselia jamur R. solani dan S. rolfsii masing-masing berumur 5 hari diambil dengan menggunakan cork borer ukuran 0,5 cm ditanam pada media PDA berhadapan dengan B. cereus dengan jarak 3 cm. Penelitian disusun dalam rancangan acak lengkap dan diulang empat kali. Pengamatan dilakukan terhadap persentase penghambatan pertumbuhan jamur oleh Bacillus sp. dan laju pertumbuhan jamur. Hasil penelitian menunjukkan bahwa Bacillus sp. mampu menghambat pertumbuhan miselia R. solani dan S. rolfsii masing-masing sebesar 68,9% dan 33% pada hari ketiga setelah perlakuan. Keberadaan B. cereus dapat memperlambat laju pertumbuhan R. solani (15,5 mm/24 jam), dibandingkan perlakuan kontrol (tanpa B. cereus) sebesar 19,7 mm/24 jam. Hasil ini menunjukkan bahwa B. cereus dapat menghambat pertumbuhan R. solani dan berpotensi untuk dikembangkan sebagai agens hayati. Rhizoctonia solani and Sclerotium rolfsii (the causal agents of damping off disease on various hosts) are the group of sterile fungi that cannot produce spores. Nevertheless, they produce sclerotia as primary inocula and resting spores when facing unfavorable condition. Several control methods using chemical fungicides and solarization had been conducted, but the results were still inconsistent. In addition, the use of Bacillus sp. as a biological control agent for several plant diseases had provided successful results. Furthermore, the research aimed to evaluate the potency of B. cereus towards R. solani and S. rolfsii in vitro was carried out in the laboratory of phytopathology using dual culture method on PDA medium. Five days of R. solani and S. rolfsii miselia were plugged and inoculated on PDA medium toward B. cereus. The research was arranged by completely randomized design with four replicates. The percentage of fungal inhibition and fungal growth rate were observed. The result showed that B. cereus exhibited mycelial growth inhibition activity of R. solani and S. rolfsii by 68,9% and 33% three days after treatments, respectively. The result also indicated that B. cereus has a potential prospect to be developed as a biological control agent because the bacteria could suspend the growth rate of R. solani.

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Chondrostereum purpureum as an inundative biological control agent for invasive woody weeds in New Zealand

New Zealand Plant Protection ◽

10.30843/nzpp.2010.63.6581 ◽

2010 ◽

Vol 63 ◽

pp. 274-274

Author(s):

T.D. Ramsfield ◽

C.A. Carlson ◽

M.W.P. Power ◽

D. Skudder

Keyword(s):

Biological Control ◽

Biological Control Agent ◽

Populus Trichocarpa ◽

Control Agent ◽

Lesion Length ◽

Weed Species ◽

Buddleja Davidii ◽

Inundative Biological Control ◽

Salix Matsudana ◽

Chondrostereum Purpureum

Chondrostereum purpureum is a basidiomycete fungus that is being investigated as an inundative biological control agent for invasive woody weeds This study was conducted to assess the susceptibility of seven species of weeds to C purpureum The species that were inoculated in this trial were broom (Cytisus scoparius) gorse (Ulex europeaus) buddleia (Buddleja davidii) Himalayan honeysuckle (Leycesteria formosa) hawthorne (Crataegus monogyna) poplar (Populus trichocarpa) and willow (Salix matsudana) Two isolates of C purpureum and a control were used and were each replicated 12 times All plants were potted and the trial took place under nursery conditions Mortality and canker size were measured 6 months after inoculation Data were analysed using SAS The highest mortality (50) was recorded for broom with one isolate but very little mortality was observed across the other species A highly significant weed by isolate interaction was observed with regards to lesion length with weed species susceptibility varying with respect to one of the C purpureum isolates Hawthorn and willow had greater lesion lengths after inoculation with the same isolate that had caused mortality in broom The results from this trial are being used to direct a larger field trial

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Screening of Tomato Seed Bacterial Endophytes for Antifungal Activity Reveals Lipopeptide Producing Bacillus siamensis Strain NKIT9 as a Potential Bio-Control Agent

Frontiers in Microbiology ◽

10.3389/fmicb.2021.609482 ◽

2021 ◽

Vol 12 ◽

Author(s):

Ayushi Sharma ◽

Nutan Kaushik ◽

Abhishek Sharma ◽

Abhay Bajaj ◽

Mandar Rasane ◽

...

Keyword(s):

Antifungal Activity ◽

Fungal Pathogens ◽

Disease Incidence ◽

Control Agent ◽

Rrna Gene ◽

Dual Culture ◽

Bacterial Endophytes ◽

High Definition ◽

Tomato Seed ◽

Diversity Pattern

The current study investigates the diversity pattern and fungicidal potential of bacterial endophytes isolated from two different organic varieties of tomato plants (V1 and V2). A total of seventy-five bacterial isolates identified by 16S rRNA gene sequencing revealed a majority of genus as Bacillus and one Planococcus, which were grouped into eight different species. The Shannon diversity H’ (1.56), Simpson’s index of diversity (0.93), Magalef’ index (2.23), Evenness (0.96), and Species richness (7) indicated the high endophytic bacterial diversity in the V1 variety of the tomato. Bacterial endophytes isolated from both of the varieties were screened for their antifungal activity against five economically critical fungal pathogens (viz., Botrytis cinerea, Rhizoctonia solani, Fusarium solani, Verticillium lateritium, and Alternaria solani) of tomato crop through dual culture assay. The data revealed B. siamensis strain NKIT9 as the most potent antagonist, significantly (p < 0.05) inhibiting the mycelial growth between 75 to 90% against selected fungal pathogens. High bioactivity of lipopeptide extract of strain NKIT9 was recorded against R. solani with minimum IC50 value of 230 μg/ml. The Ultra Performance Liquid Chromatography-High Definition Mass Spectrometry (UPLC-HDMS) analysis of this lipopeptide extract revealed the presence of Surfactin and Bacillomycin D. Furthermore, in-vitro results showed that the selected bacterial strain significantly minimized the disease incidence in damping-off assay which makes this strain a promising antifungal bio-control agent. Moreover, in the pot experiment the NKIT9 increased the fruit yield by 59.2% compared with the untreated R. solani infested control.

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