Isolation, identification, and biological control in vitro of tail rot pathogen strain from Hippocampus kuda

The use of biological control is becoming a common practice in plant production. One overlooked group of organisms potentially suitable for biological control are Rhizoctonia-like (Rh-like) fungi. Some of them are capable of forming endophytic associations with a large group of higher plants as well as mycorrhizal symbioses. Various benefits of endophytic associations were proved, including amelioration of devastating effects of pathogens such as Fusarium culmorum. The advantage of Rh-like endophytes over strictly biotrophic mycorrhizal organisms is the possibility of their cultivation on organic substrates, which makes their use more suitable for production. We focused on abilities of five Rh-like fungi isolated from orchid mycorrhizas, endophytic fungi Serendipita indica, Microdochium bolleyi and pathogenic Ceratobasidium cereale to inhibit the growth of pathogenic F. culmorum or Pyrenophora teres in vitro. We also analysed their suppressive effect on wheat infection by F. culmorum in a growth chamber, as well as an effect on barley under field conditions. Some of the Rh-like fungi affected the growth of plant pathogens in vitro, then the interaction with plants was tested. Beneficial effect was especially noted in the pot experiments, where wheat plants were negatively influenced by F. culmorum. Inoculation with S. indica caused higher dry shoot biomass in comparison to plants treated with fungicide. Prospective for future work are the effects of these endophytes on plant signalling pathways, factors affecting the level of colonization and surviving of infectious particles.

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Infection Potential of Pleospora allii and Evaluation of Methods for Reduction of the Overwintering Inoculum of Brown Spot of Pear

Plant Disease ◽

10.1094/pd-90-1511 ◽

2006 ◽

Vol 90 (12) ◽

pp. 1511-1516 ◽

Cited By ~ 15

Author(s):

Isidre Llorente ◽

Albert Vilardell ◽

Emilio Montesinos

Keyword(s):

Biological Control ◽

Brown Spot ◽

Control Methods ◽

Optimum Temperature ◽

Chemical Methods ◽

Stemphylium Vesicarium ◽

Mechanical Methods ◽

Pleospora Allii ◽

Evaluation Of Methods

The capacity for germination and pathogenicity to pear leaves of ascospores of Pleospora allii, the teleomorph of Stemphylium vesicarium, causal agent of brown spot of pear, were studied in vitro. Most ascospores germinated within 1 h at temperatures between 15 and 20°C, and the optimum temperature for germination was 18.9°C. Infections developed on wounded and non-wounded detached pear leaves, but were more frequent on wounded leaves. The minimum infective dose was one ascospore per wound. Biological, chemical, and mechanical methods for decreasing overwintering inoculum of P. allii were evaluated. Ascospores were discharged from March to May, depending on the orchard and year. Leaf shredding or removal were the most effective methods of reducing overwintering inoculum. Biological control methods based on application of Thichodermasp. formulations were partially effective. Chemical methods based on copper and urea treatments were ineffective.

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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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Effect of Timing of Application of the Biological Control Agent Microsphaeropsis ochracea on the Production and Ejection Pattern of Ascospores by Venturia inaequalis

Phytopathology ◽

10.1094/phyto.2004.94.12.1305 ◽

2004 ◽

Vol 94 (12) ◽

pp. 1305-1314 ◽

Cited By ~ 11

Author(s):

O. Carisse ◽

D. Rolland

Keyword(s):

Biological Control ◽

Biological Control Agent ◽

Venturia Inaequalis ◽

Apple Scab ◽

Control Agent ◽

Sterile Leaf ◽

Ascospore Production ◽

Fall Application ◽

Leaf Disks

Field and in vitro trials were conducted to establish the influence of the biological control agent Microsphaeropsis ochracea on the ejection pattern of ascospores by Venturia inaequalis and on apple scab development, and to establish the best timing of application. The ejection pattern of ascospores was similar on leaves sprayed with M. ochracea and on untreated leaves. Fall application of M. ochracea combined with a delayed-fungicide program was evaluated in orchards with intermediate and high scab risk. For both orchards, it was possible to delay the first three and two infection periods in 1998 and 1999, respectively, without causing significant increase or unacceptable leaf and fruit scab incidence. To evaluate the best timing of application, sterile leaf disks were inoculated with V. inaequalis and then with M. ochracea 0, 2, 4, 6, 8, 10, 12, 14, and 16 weeks later. After incubation under optimal conditions for pseudothecia development, the number of ascospores was counted. Similarly, M. ochracea was sprayed on scabbed leaves on seven occasions from August to November 1999 and 2000. Leaves were overwintered on the orchard floor and ascospore production was evaluated the following spring. Ascospore production was reduced by 97 to 100% on leaf disks inoculated with M. ochracea less than 6 weeks after inoculation with V. inaequalis, but ascospore production increased with increasing period of time when M. ochracea was applied 8 to 16 weeks after the inoculation with V. inaequalis. In the orchard, the greatest reduction in production of ascospores (94 to 96% in 2000 and 99% in 2001) occurred on leaves sprayed with M. ochracea in August. The production of ascospores was reduced by 61 to 84% in 2000 and 93% in 2001 on leaves sprayed with M. ochracea in September, reduced by 64 to 86% in 2000 and 74 to 89% in 2001 on leaves sprayed in October, and reduced by 54 and 67% in 2000 and 2001, respectively, on leaves sprayed in November. It was concluded that M. ochracea should be applied in August or September and that ascospore maturation models and delayed-fungicide program could be used in orchards treated with this biological control agent.

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Virulence and Genetic Characterization of Six Baculovirus Strains Isolated From Different Populations of Spodoptera Frugiperda (Lepidoptera: Noctuidae)

10.21203/rs.3.rs-988050/v1 ◽

2021 ◽

Author(s):

Ingrid Zanella-Saenz ◽

Elisabeth A. Herniou ◽

Jorge E. Ibarra ◽

Ma.Cristina Del Rincón-Castro ◽

Ilse Alejandra Huerta-Arredondo

Keyword(s):

Biological Control ◽

Cell Cultures ◽

Spodoptera Frugiperda ◽

Fall Armyworm ◽

The United States ◽

Infection Mechanisms ◽

Different Populations

Abstract Fall armyworm (FAW), Spodoptera frugiperda (Smith, 1797), is a polyphagous, voracious, and economically important agricultural pest. Biological control of FAW is a strategy that must be further explored. This study evaluated six baculovirus strains isolated from infected FAW larvae from Mexico, Argentina, Honduras, and the United States. Five alphabaculoviruses (SfNPV-An2, SfNPV-Arg, SfNPV-Fx, SfNPV-Ho and SfNPV-Sin) and one betabaculovirus (SfGV-RV), were tested against FAW larvae, showing a wide diversity of virulence levels among strains when their estimated LC50s were compared, being SfNPVArg, SfNPV-Ho and SfNPV-Fx more virulent than SfNPV-An 2 , SfNPV-Sin and SfGV-RV. To determine any virulence difference in vitro studies of these isolates, Sf9 cell cultures were used. Interestingly, only ODVs from four of the test SfNPV strains showed infectivity on Sf9 cell cultures, and some differences in virulence were observed. Genomic restriction analyses and partial sequences of lef-8, lef-9 , and polh/granulin genes showed little variability among alphabaculoviruses, both, among them and with previously reported sequences. However, sequences from SfGV-RV were closer to previously reported sequences from the SfGVVG008 strain than the SfGV-Arg and SfGV-VG014 strains. The great difference in the in vivo virulence was not correlated with great similarity among the isolates. The characterization of these six baculoviruses isolates offers the basis for exploring their potential as biological control agents against S. frugiperda, as well the initial studies on their specific infection mechanisms, evolution, and ecology.

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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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Isolation, Characterization, and Identification of Biological Control Agent for Potato Soft Rot in Bangladesh

The Scientific World JOURNAL ◽

10.1100/2012/723293 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 8

Author(s):

M. M. Rahman ◽

M. E. Ali ◽

A. A. Khan ◽

A. M. Akanda ◽

Md. Kamal Uddin ◽

...

Keyword(s):

Biological Control ◽

Biological Control Agent ◽

Erwinia Carotovora ◽

Soft Rot ◽

Control Agent ◽

Antagonistic Activity ◽

Antagonistic Effect ◽

Antagonistic Bacteria ◽

And Storage

A total of 91 isolates of probable antagonistic bacteria of potato soft rot bacteriumErwinia carotovorasubsp.carotovora(Ecc) were extracted from rhizospheres and endophytes of various crop plants, different soil varieties, and atmospheres in the potato farming areas of Bangladesh. Antibacterial activity of the isolated probable antagonistic bacteria was testedin vitroagainst the previously identified most common and most virulent soft rot causing bacterial strain Ecc P-138. Only two isolates E-45 and E-65 significantly inhibited thein vitrogrowth of Ecc P-138. Physiological, biochemical, and carbon source utilization tests identified isolate E-65 as a member of the genusBacillusand the isolate E-45 asLactobacillussp. The stronger antagonistic activity against Ecc P-138 was found in E-65in vitroscreening and storage potatoes. E-65 reduced the soft rot infection to 22-week storage potatoes of different varieties by 32.5–62.5% in model experiment, demonstrating its strong potential to be used as an effective biological control agent for the major pectolytic bacteria Ecc. The highest (62.5%) antagonistic effect of E-65 was observed in the Granola and the lowest (32.7%) of that was found in the Cardinal varieties of the Bangladeshi potatoes. The findings suggest that isolate E-65 could be exploited as a biocontrol agent for potato tubers.

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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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Kemampuan Bakteri Endofit Akar dan Ubi Kentang untuk Menekan Penyakit Busuk Lunak (Erwinia carotovora pv. carotovora) pada Ubi

Agrikultura ◽

10.24198/agrikultura.v27i3.10880 ◽

2016 ◽

Vol 27 (3) ◽

Author(s):

Noor Istifadah ◽

Muhamad Salman Umar ◽

Sudarjat Sudarjat ◽

Luciana Djaya

Keyword(s):

Biological Control ◽

Potato Tuber ◽

Endophytic Bacteria ◽

Erwinia Carotovora ◽

Soft Rot ◽

Soft Rot Disease ◽

Post Harvest ◽

Rot Disease

ABSTRACTThe abilities of endophytic bacteria from potato roots and tubers to suppress soft rot disease (Erwinia carotovora pv. carotovora) in potato tuberSoft rot disease caused by Erwinia carotovora pv. carotovora is one of limiting factors in cultivation and post harvest of potato. The eco-friendly control measure that can be developed for controlling the diseases is biological control. Microbes that are potential as biological control agents include endophytic bacteria. This paper discussed the results of study examining the potential of endophytic bacteria isolated from roots and tubers of potato to inhibit the growth of E. carotovora pv. carotovora in vitro and suppress soft rot disease in potato tuber. The results showed that among 24 isolates examined, four isolates of endophytic bacteria (one isolate from potato tuber and three isolates from potato roots) inhibited the growth of E. carotovora pv. carotovora in vitro with inhibition zone 3.5-6.8 mm. In the in vivo test, the isolates inhibited the soft rot disease in potato tuber by 71.5-86.4%. The isolate that tended to show relatively better inhibition in vitro and in vivo was isolate from potato tuber which is CK U3 (Lysinibacillus sp.)Keywords: Biological control, Endophytic bacteria, Post-harvest, Potato, Soft rot diseaseABSTRAKPenyakit busuk lunak yang disebabkan bakteri Erwinia carotovora pv. carotovora, merupakan salah satu kendala dalam budidaya dan pascapanen kentang. Cara pengendalian ramah lingkungan yang dapat dikembangkan untuk menekan penyakit tersebut adalah pengendalian biologi. Kelompok mikroba yang berpotensi sebagi agens pengendali biologi adalah bakteri endofit. Artikel ini mendiskusikan potensi isolat bakteri endofit yang berasal dari ubi dan akar kentang untuk menghambat pertumbuhan bakteri E. carotovora pv. carotovora secara in vitro dan menekan perkembangan penyakit busuk lunak pada ubi kentang. Hasil percobaan menunjukkan bahwa diantara 24 isolat bakteri yang diuji, terdapat empat isolat bakteri endofit (satu isolat dari ubi kentang dan tiga isolat dari akar kentang) yang dapat menghambat pertumbuhan bakteri E. carotovora pv. carotovora secara in vitro dengan zona penghambatan sebesar 3,5-6,8 mm. Pada pengujian secara in vivo, isolat-isolat tersebut dapat menekan perkembangan penyakit busuk lunak pada ubi kentang sebesar 71,5-86,4%. Isolat yang cenderung menunjukkan penghambatan relatif lebih baik secara in vitro dan in vivo adalah isolat bakteri endofit asal ubi kentang yaitu isolat CK U3 (Lysinibacillus sp.).Kata Kunci: Pengendalian biologi, Bakteri endofit, Pascapanen, Kentang, Penyakit busuk basah

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