Two Philippine Photorhabdus luminescens strains inhibit the in vitro growth of Lasiodiplodia theobromae, Fusarium oxysporum f. sp. lycopersici, and Colletotrichum spp.

Abstract Background Fungal phytopathogens are one of the leading causes of loss in global food production. Chemical fungicides have always been used to control the phytopathogens to mitigate losses. However, it is widely known that this approach is not sustainable. Thus, it is essential to develop alternative control methods, such as the use of biological control agents. Results This study provided a preliminary data on the efficacy of 2 local Photorhabdus strains, associated with Heterorhabditis indica BSDS and H. indica MAP, against selected post-harvest fungal phytopathogens, Fusarium oxysporum f. sp. lycopersici, Lasiodiplodia theobromae, Colletotrichum musae, and another Colletotrichum sp., by measuring their in vitro inhibitory activity. The Photorhabdus strains were isolated from the hemolymph of Ostrinia furnicalis infected with H. indica BSDS and H. indica MAP and grown selectively on NBTA media. Firstly, the bacterial endosymbionts' generic identity was confirmed through colony PCR based on a Photorhabdus Txp40 toxin-specific marker. Species identity was then elucidated through 16s marker-assisted GenBank mining as P. luminescens, sharing 99.51–99.58% similarity with P. luminescens subsp. akhurstii (Accession no. AY278643.1). Anti-fungal activity was observed by the bioassay experiments, using cell-free culture filtrates (CFCs), obtained from P. luminescens tryptic soy broth suspensions (OD600 = 2.0) amended in PDA medium (25%v/v) based on percentage growth inhibition. The CFCs of P. luminescens BSDS showed a significantly higher suppressive activity against Colletotrichum musae, Colletotrichum sp., and Lasiodiplodia theobromae, with 93.18 ± 0.46%, 74.15 ± 0.54%, and 60.51 ± 2.04% growth inhibition, respectively, while the CFC of P. luminescens MAP showed a significantly higher suppressive activity against F. oxysporum f. sp. lycopersici with 21.87 ± 0.71% growth inhibition. Conclusions The results strongly showed that these strains of Photorhabdus can be promising biological control agents against these fungal phytopathogens. Further extensive research is warranted for the development of these promising biofungicides into a practical, economically viable, and environment-friendly control strategy that can be incorporated into any integrated pest management program.

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Biocontrol of seed-borne Alternaria raphani and A. brassicicola

Canadian Journal of Microbiology ◽

10.1139/m87-149 ◽

1987 ◽

Vol 33 (10) ◽

pp. 850-856 ◽

Cited By ~ 27

Author(s):

G. Vannacci ◽

G. E. Harman

Keyword(s):

Biological Control ◽

Host Range ◽

Trichoderma Harzianum ◽

Pythium Species ◽

Biological Control Agents ◽

Fusarium Sp ◽

Chamber Studies ◽

Growth Chamber Studies ◽

Radish Seedlings

Forty-two microorganisms were tested as biological control agents against Alternaria raphani and A. brassicicola. Tests were conducted for in vitro antagonistic ability, for ability to control the pathogens on naturally infected seeds germinated on moistened blotters, and in planting mix in growth chamber studies, and for their ability to reduce pod infection. The organisms tested were obtained from cruciferous seeds or were strains already identified as being effective against soil-borne Pythium species. The blotter test indicated that six organisms increased both the number of healthy seedlings and the number of seedlings produced from A. raphani infected radish seeds. An additional seven strains improved either germination or increased the number of healthy seedlings. Twenty-nine organisms increased the number of healthy cabbage seedlings from A. brassicicola infected seeds, but total germination was not modified by any treatment. Experiments in planting mix showed that five antagonists (Chaetomium globosum, two strains of Trichoderma harzianum, T. koningii, and Fusarium sp.) increased the number of healthy plants in both radish samples tested, while four additional antagonists provided a significant increase in only one of the samples tested. The five antagonists that consistently increased numbers of healthy radish seedlings also decreased pod infection by A. raphani. None were as effective as iprodrone, however. Several effective antagonists were found to be mycoparasitic against Alternaria spp. Some strains of Trichoderma previously found to be effective against Pythium spp. were also effective against Alternaria spp., indicating that these strains have a wide host range.

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Daily Indexes for Predation and Growth of Nematophagous Mushrooms Species of Hohenbuehelia (Pleurotaceae) on Panagrellus redividus

Journal of Agricultural Science ◽

10.5539/jas.v10n3p276 ◽

2018 ◽

Vol 10 (3) ◽

pp. 276

Author(s):

Cleonice Lubian ◽

Danielle Dutra Martinha ◽

Roberto Luis Portz ◽

Alexandre Gonçalves dos Santos e Silva Filho ◽

Vagner Gularte Cortez ◽

...

Keyword(s):

Biological Control ◽

Growth Speed ◽

Test Evaluation ◽

Biological Control Agents ◽

Panagrellus Redivivus ◽

Mycelia Growth ◽

Living Organisms

Biological control is a method of controlling pests through the use of other living organisms. The purposes of this study were to test Hohenbuehelia species as biological control agents against Panagrellus redivivus in vitro, evaluating nematodes influence on mycelia growth; establishing daily indexes for predation and growth and setting predation percentage. Five species previously identified as 436-Hohenbuehelia mastrucata (Nematoctonus hamatus), 528-H. bullulifera (not described so far), 581-H. paraguayensis (N. sp.), 582-H. sp. (N. sp.) and 631-H. portegna (N. campylosporus) were submitted to anamorphic purification directly from basidioma. Afterwards, 100 nematodes were added to each pure colony for predation test. Evaluation started right after 24 hours of nematode-fungus interaction. Immobilized and/or penetrated nematodes were counted and mycelia growth was measured. Results were subjected to variance analyses. Hohenbuehelia mastrucata had the best performance in growth speed, followed by H. portegna and H. paraguayensis; Nematodes multiplyied much but none specie grew more as an influence of their movement under mycelium, however all species formed trap devices and some of them produced adhesive or repelent substances. Trap devices were formed in control plates also. The plates of H. paraguayensis without nematodes grew more than treatments. Cumulative predation of H. portegna was the highest at 24 (195.5%) and 48 hours (235%). At the last evaluation day, H. paraguayensis preyed the same amount (185.75%) than H. portegna, followed by H. mastrucata (109.51%). Resulst of predation daily indexes displayed chronological activity for each isolate, where H. portegna was very reactive at first 24 hours, H. mastrucata raised its predacious activity in 48 hours being constant from this time on and H. paraguayensis pointed out itself at 72 hours. Other species presented low predation and growth indexes throughout experiment.

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In vitro and in vivo Assay for Assessment of the Biological Control Potential of Streptomyces sp. KT

Journal of Plant Studies ◽

10.5539/jps.v7n1p10 ◽

2017 ◽

Vol 7 (1) ◽

pp. 10

Author(s):

Tatsuya Ohike ◽

Minori Maeda ◽

Tetsuya Matsukawa ◽

Masahiro Okanami ◽

Shin’ichiro Kajiyama ◽

...

Keyword(s):

Biological Control ◽

Suppressive Effect ◽

Phytopathogenic Fungi ◽

Dual Culture ◽

Biological Control Agents ◽

Bipolaris Oryzae ◽

Biological Control Potential ◽

Dual Culture Assay

Rhizoctonia solani is fungal plant pathogen that infects many different host plants. Recently, biological control agents that are friendly to the environment and ecosystems have attracted much attention as an alternative to the use of chemical fungicide which have been used worldwide to control soil borne pathogens including R. solani. In this study, 53 strains of actinomycetes isolated from environmental soils, and antifungal activities of them were assessed by the dual culture assay. Strain KT showed strong inhibitory activities against 8 phytopathogenic fungi. A great suppressive effect on R. solani growth was observed in the inoculation test of plants using cucumber and chin-geng-sai. In addition, infection of Bipolaris oryzae also could be suppressed in the detached leaf assay using oats. As a result of genetic analysis, it was shown that KT was a species closely related to Streptomyces lavenduligriseus NRRL B-3173T. However, as far as we know, there is no report for biological control agents using S. lavenduligriseus. This study suggests that the strain KT may useful as biological control agents to suppress various crop diseases.

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RISK ANALYSIS IN THE RELEASE OF BIOLOGICAL CONTROL AGENTS: ANTAGONISTIC FUSARIUM OXYSPORUM AS A CASE STUDY

Acta Horticulturae ◽

10.17660/actahortic.1999.482.21 ◽

1999 ◽

pp. 145-152 ◽

Cited By ~ 1

Author(s):

M.L. Gullino ◽

Q. Migheli

Keyword(s):

Biological Control ◽

Risk Analysis ◽

Fusarium Oxysporum ◽

Biological Control Agents

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Immobilized Bacillus subtilis by ionic gelation as biocontrol alternative of Fusarium oxysporum f.sp. lycopersici

Indian Journal of Agricultural Research ◽

10.18805/ijare.a-347 ◽

2018 ◽

Author(s):

Castañeda Alvarez Estefania ◽

Sánchez Leal Ligia

Keyword(s):

Biological Control ◽

Bacillus Subtilis ◽

Fusarium Oxysporum ◽

Sodium Alginate ◽

Ionic Gelation ◽

Cellular Viability ◽

Market Demand ◽

Control Activity ◽

Pests And Diseases

For farmers the use of agrochemicals is the preferred method to control pests and diseases. Considering the market demand for biological control products, the encapsulation could be a competent alternative to current commercial formulations for cellular viability and controlled release. The purpose of this study was to use ionic gelation with sodium alginate, starch and maltodextrin to immobilize Bacillus subtilis and to evaluate the biocontrol effect against Fusarium oxysporum f. sp. lycopersici in vitro. The matrix with a concentration of 2% sodium alginate, 1% starch, and 1% maltodextrin is a suitable method for cellular viability and biological control activity against Fusarium oxysporum f. sp. lycopersici, with a reduction of mycelial growth of 49.6% and a survival rate for Bacillus subtilis of 98.05% (p less than 0.0001).The use of immobilized bacteria as biological control agents are sustainable and effective bio-inputs that could be used at industrial scale and benefit the tomato crops against attack by Fusarium oxysporum f. sp. lycopersici.

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Suppression of Stem-End Rot on Avocado Fruit Using Trichoderma spp. in the Central Highlands of Kenya

Advances in Agriculture ◽

10.1155/2021/8867858 ◽

2021 ◽

Vol 2021 ◽

pp. 1-6

Author(s):

E. K. Wanjiku ◽

J. W. Waceke ◽

J. N. Mbaka

Keyword(s):

Growth Inhibition ◽

Fungal Pathogen ◽

Mycelial Growth ◽

Culture Technique ◽

Global Market ◽

Dual Culture ◽

Postharvest Diseases ◽

Trichoderma Spp ◽

Lasiodiplodia Theobromae

Demand for organic avocado fruits, together with stringent food safety standards in the global market, has made producers to use alternative, safe, and consumer-friendly strategies of controlling the postharvest fungal disease of avocado fruits. This study assessed the in vitro efficacy of Trichoderma spp. (T. atroviride, T. virens, T. asperellum, and T. harzianum) against isolated avocado stem-end rot (SER) fungal pathogens (Lasiodiplodia theobromae, Neofusicoccum parvum, Nectria pseudotrichia, and Fusarium solani) using a dual culture technique. The Trichoderma spp. were also evaluated singly on postharvest “Hass” avocado fruits. Spore suspension at 5 × 104 conidial/ml of the Trichoderma spp. was applied on the avocado fruits at three time points, twenty-four hours before the fungal pathogen (preinoculation), at the same time as the fungal pathogen (concurrent inoculation), and 24 hours after the fungal pathogen (postinoculation). In the in vitro study, T. atroviride showed the highest mycelial growth inhibition against N. parvum (48%), N. pseudotrichia (55%), and F. solani (32.95%), while T. harzianum had the highest mycelial growth inhibition against L. theobromae. Trichoderma asperellum was the least effective in inhibiting the mycelial growth of all the pathogens. Similarly, T. virens showed the highest mycelial growth inhibition against N. pseudotrichia at 45% inhibition. On postharvest “Hass” fruits, T. atroviride showed the highest efficacy against N. parvum, N. pseudotrichia, and F. solani in all the applications. Trichoderma virens and T. harzianum were most effective against all the pathogens during postinoculation, while Lasiodiplodia theobromae was best controlled by T. virens, T. harzianum, and T. asperellum during postinoculation. Both T. atroviride and T. harzianum present a potential alternative to synthetic fungicides against postharvest diseases of avocado fruits, and further tests under field conditions to be done to validate their efficacy. The possibility of using Trichoderma spp. in the management of SER on avocado fruits at a commercial level should also be explored.

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Evaluation of in vitro antagonistic activity of fungi from peatlands against Ganoderma species under acidic condition

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d210709 ◽

2020 ◽

Vol 21 (7) ◽

Author(s):

SUPRIYANTO ◽

PURWANTO ◽

S.H. POROMARTO ◽

SUPYANI

Keyword(s):

Biological Control ◽

Antagonistic Activity ◽

Biological Control Agents ◽

Antagonistic Fungi ◽

High Incidence ◽

Acidic Conditions ◽

Mineral Soils ◽

Ph Range ◽

Biological Methods

Abstract. Supriyanto, Purwanto, Poromarto SH, Supyani. 2020. Evaluation of in vitro antagonistic activity of fungi from peatlands against Ganoderma species under acidic conditions. Biodiversitas 21: 2935-2945. The use of peatlands is a significant contributor to the world’s palm oil production. A serious problem of oil palm plantations in peatlands is the high incidence of basal stem rot (BSR) disease caused by Ganoderma, which has a higher attack rate than on mineral soils. There is no effective way to control Ganoderma in peatlands. At present, the effort for the same focuses on environment-friendly biological methods; however, this is constrained by the unavailability of appropriate biological agents for peatlands. The development of biological control agents for peatlands is hampered by limited data on biological control of Ganoderma in peatlands. This research was conducted to evaluate the in vitro antagonistic activity of fungi isolated from a peatland in acidic pH conditions. Twenty-seven Ganoderma-antagonistic fungi from peatland were evaluated for their activity and their ability to antagonism in vitro within a pH range of 2-7. The results show that most antagonistic fungi from peatland, based on biomass weight, the sporulation ability, and germination of conidium, were able to grow optimally at pH 3.0-4.0, indicating that most of the Ganoderma-antagonistic fungi from peatland can be used as biological control agents for BSR on oil palms in peatlands.

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Non-Synergistic Effect of Trichoderma harzianum and Glomus spp. in Reducing Infection of Fusarium Wilt in Banana

Pathogens ◽

10.3390/pathogens8020043 ◽

2019 ◽

Vol 8 (2) ◽

pp. 43 ◽

Cited By ~ 2

Author(s):

Arfe Castillo ◽

Cecirly Puig ◽

Christian Cumagun

Keyword(s):

Biological Control ◽

Synergistic Effect ◽

Fusarium Oxysporum ◽

Fusarium Wilt ◽

Trichoderma Harzianum ◽

Root Weight ◽

Biological Control Agents ◽

Competitive Effects ◽

Glomus Spp ◽

Race 4

Philippine banana is currently threatened by Fusarium oxysporum f. sp. cubense Tropical Race 4 (FocR4). This study investigated the use of Trichoderma harzianum pre-treated with Glomus spp, as a means of managing Fusarium wilt on young ‘Lakatan’ banana seedlings. Results showed that Glomus applied basally significantly improved banana seedling growth with increased increment in plant height and pseudostem diameter and heavier root weight. The application of Glomus spp. alone offered 100% protection to the ‘Lakatan’ seedlings against FocR4 as indicated by the absence of the wilting symptom. A combination of T. harzianum and Glomus spp. also gave significant effect against Fusarium wilt through delayed disease progression in the seedlings but was not synergistic. Competitive effects were suspected when application of the two biological control agents on banana roots was done simultaneously.

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The in vitro inhibition of Phytophthora clandestina by some rhizobia and the possible role of Rhizobium trifolii in biological control of Phytophthora root rot of subterranean clover

Australian Journal of Agricultural Research ◽

10.1071/ar99047 ◽

1999 ◽

Vol 50 (8) ◽

pp. 1469 ◽

Cited By ~ 5

Author(s):

S. Simpfendorfer ◽

T. J. Harden ◽

G. M. Murray

Keyword(s):

Biological Control ◽

Root Rot ◽

Subterranean Clover ◽

Trifolium Subterraneum ◽

Root Disease ◽

Rhizobium Trifolii ◽

Biological Control Agents ◽

Control Activity ◽

Phytophthora Root Rot

The interaction between 29 isolates of Rhizobium and the in vitro growth of 3 strains of Phytophthora clandestina was investigated to determine the potential of these bacteria as biological control agents against root rot of subterranean clover (Trifolium subterraneum L.). The biological control activity of Rhizobium on the severity of root disease in seedlings was also investigated under glasshouse conditions. Thirteen of the 29 Rhizobium isolates caused significant reductions in the hyphal growth of the 3 P. clandestina isolates examined. Inoculation of seedlings with Rhizobium trifolii reduced the severity of root disease by 14–58% with corresponding increases in dry matter production of 20–73%. These results indicate that Rhizobium species have potential as biological control agents against the root rot of T. subterraneum seedlings caused by P. clandestina.

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