scholarly journals ANTAGONISTIC POTENTIAL OF TRICHODERMA HARZIANUM AGAINST FUSARIUM OXYSPORUM F. SP. CUBENSE ASSOCIATED WITH PANAMA WILT OF BANANA

2017 ◽  
Vol 29 (1) ◽  
pp. 111
Author(s):  
Babar Khan ◽  
Zuniara Akash ◽  
Shahzad Asad ◽  
Nazir Javed ◽  
Nasir A. Rajput ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Trichoderma Harzianum ◽  
Vascular System ◽  
Biological Control Agent ◽  
Colony Growth ◽  
Research Area ◽  
Control Agent ◽  
Research Centre ◽  
Antagonistic Potential

Fusarium oxysporum f. sp. cubense is a soil loving pathogen of banana that can cause distortion of vascular system. It is responsible for the disease Fusarium wilt of bananas also renowned as panama wilt disease that has responsible of immense losses in the banana industry worldwide. In this study, diseased samples were collected from rhizosphere of banana plants in the research area of National Agriculture Research Centre (NARC), Islamabad and cultured on PDA to isolate pathogenic strains of F. oxysporium f. sp. cubense. Antagonistic potential of Trichoderma harzianum against F. oxysporum f. sp. cubense was evaluated under controlled conditions. T. harzianum produced up to 75.5% inhibition of colony growth of the pathogen followed by incubation for 72 h at 28+2°C in vitro. In pot culture T. harzianum considerably reduced disease severity. It proves that it is a potential biological control agent against banana wilt pathogen.

scholarly journals Cladobotryum mycophilum as Potential Biocontrol Agent

Agronomy ◽  
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.

scholarly journals Foliar endophytic fungi of Theobroma cacao stimulate more than inhibit Moniliophthora spp. growth and behave more as an endophytes than pathogens.

2020 ◽  
Author(s):  
Miriam Villavicencio ◽  
Laura Schuller ◽  
Fernando Espinosa ◽  
Carlos Noceda ◽  
Daynet Sosa del Castillo ◽  
...  
Keyword(s):  
Endophytic Fungi ◽  
Theobroma Cacao ◽  
Biological Control Agent ◽  
Pathogenic Fungi ◽  
Colony Growth ◽  
Control Agent ◽  
Inhibition Of Growth ◽  
Pestalotiopsis Microspora ◽  
Moniliophthora Roreri

Abstract The two most disastrous diseases of Theobroma cacao in Ecuador are caused by the pathogenic fungi Moniliophthora roreri (MR, Frosty pod) and M. perniciosa (MP, Witches' broom). Both diseases are prevalent in Ecuador since its detection in 1916 and 1921, respectively. One hundred and twenty-six isolates were isolated from healthy T. cacao leaves, originated from five nurseries in the Ecuadorian Coast. Isolates were screened in vitro for their stimulation/inhibition of growth of MR & MP. The endophytic fungi influenced the growth of Moniliophthora spp. in different manners, 91/126 of the tested isolates stimulated somehow the colony growth of both pathogens, and only 30 and 5 isolates always inhibited the mycelial growth of MR & MP, respectively. The highest percentage of growth inhibitions against MR was 71%, but quite lower for MP (18%). Only two isolates caused symptoms of chlorosis and necrosis in leaves and fruits Phomopsis spp. (Ascomycota) and Psathyrella sp. (Basidiomycota). Twenty-four isolates from 11 taxa caused necrosis only fruits (Ascomycota: Phomopsis spp., Phoma sp., Colletotrichum gloeosporioides s.l., Fusarium decemcellulare, F. equiseti, F. solani, Nectria pseudotrichia, Pestalotiopsis microspora, Didymosphaeria futilis, Xylaria venosula and Basidiomycota: Ceriporia lacerata) and four isolates/taxa infected only leaves (Phomopsis spp., Pestalotiopsis microspora, Nigrospora sphaerica and one unidentifiable isolate of Xylariaceae sp.). The non-pathogenic isolate, Hypoxylon investiens, inhibited MR in 71%, but also stimulate the growth of MP in 3%. The second-best isolate (Lasiodiplodia theobromae) only inhibit MR and MP in 58 y 15%, respectively; and, although the isolate was not pathogenic, the specie is risky to develop a biological control agent. There was no promising isolate against both MR & MP.

scholarly journals Bioassay on banana rhizome discs for selecting bacteria antagonistic to Fusarium oxysporum f. sp. cubense

2020 ◽  
pp. 2401-2410
Author(s):  
Liliane Santana Luquine ◽  
Luciano Ricardo Braga Pinheiro ◽  
Saulo Alves Santos de Oliveira ◽  
Harllen Sandro Alves Silva
Keyword(s):  
Fusarium Oxysporum ◽  
Biological Control Agent ◽  
Control Agent ◽  
In Vitro Tests ◽  
Panama Disease ◽  
Randomized Design ◽  
Alternative Materials ◽  
Completely Randomized Design ◽  
Set Up

Detached plant organs are alternative materials to in vitro tests for selecting biocontrol agents. On the other hand, the use of scales to quantify injured areas can generate inconsistent results. Rhizospheric and endophytic bacteria were selected as growth inhibitors of Fusarium oxysporum f. sp. cubense (Foc), the causal agent of Panama disease of banana. For this, rhizome discs were treated with 200 µL of antagonist suspension (109 CFU mL?1) and inoculated with the pathogen. The material was placed in plastic gerbox boxes and incubated in BOD at 25 °C for 12 days. Afterward, the area of rhizome discs (mm2) colonized by Foc was quantified by digital images. The assay was set up in a completely randomized design, with four replications and three discs per replication. The control consisted of untreated and inoculated discs. The results showed the efficiency of this method in selecting the biological control agent, as the 26 isolates were group into five different clusters, with isolates belonging to four of these groups (from ‘1’ to ‘4’) being able to reduce Foc colonization. Isolates 520EB, 993EB, and 531EB had the highest potential for inhibition, with areas of 343.3, 344.1, 364.8 mm2, respectively, promoting inhibition ranging from 53 to 56 % of the colonized area compared to the control (782.6 mm2).

scholarly journals Mycoparasitic capabilities of diverse native strain of Trichoderma spp. against Fusarium oxysporum f. sp. lycopersici

2016 ◽  
Vol 8 (2) ◽  
pp. 769-776
Author(s):  
Lakshman Prasad ◽  
Sorabh Chaudhary ◽  
Sushma Sagar ◽  
Akash Tomar
Keyword(s):  
Growth Inhibition ◽  
Fusarium Oxysporum ◽  
Biological Control Agent ◽  
Culture Method ◽  
Colony Growth ◽  
Limiting Factor ◽  
Dual Culture ◽  
Trichoderma Spp ◽  
Native Strain

The Fusarium wilt of tomato (Lycopersicon esculentum Mill.) caused by Fusarium oxysporum f. sp. lycopersici (Sacc.) Snyder and Hansen is recognised as one of the most devastating disease and major yield limiting factor in tomato growing regions worldwide. For eco-friendly and sustainable management of the disease, 19 Trichoderma native isolates belonging to 3 species of the genus, T. harzianum, T. asperellum and T. virens were evaluated in vitro against the pathogen using dual culture method. Out of 19 isolates, 8 isolates showed mycoparasitism, 8 isolates showed antibiosis and remaining showed lysis. Microscopic observations of Fusarium oxysporum f. sp. lycopersici (FOL) growth in dual cultures revealed that growth inhibition occurred just before near to contact with the antagonist. All T. harzianum isolates tested exhibited coiling around the hyphae of FOL. Isolates of T. harzianum, showed good coiling and growth inhibition of the pathogen. The T. harzianum strains did not differ in coiling pattern and gave somewhat equal coiling performances. Strains of T. asperellum, showed coiling but the coiling pattern of all these strains was different. Only one strain of T. virens showed coiling out of 2 strains. Among them T. harzianum (SVPUTh91) showed the best performance in vitro as biological control agent against FOL followed by T. asperellum and T. virens, resulting in 83, 73 and 65% reduction in colony growth, respectively.

scholarly journals Pathogenicity of Pakistani isolates of Steinernema bifurcatum and S. affine (Rhabditida: Steinernematidae) in management of stored grain pests Lasioderma serricorne and Tribolium castaneum (Coleoptera: Ptinidae, Tenebrionidae)

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Tabassum Ara Khanum ◽  
Salma Javed
Keyword(s):  
Biological Control ◽  
Tribolium Castaneum ◽  
Biological Control Agent ◽  
Economic Loss ◽  
Research Area ◽  
Control Agent ◽  
Lasioderma Serricorne ◽  
Stored Grain ◽  
Insect Infestations ◽  
Stored Grain Pests

Abstract Background Stored grain products suffer a considerable economic loss due to insect infestations. The resistance of pests to insecticide, and residues on crops are produced by the application of insecticide. Nowadays, incremental necessity has been occurred to find out alternatives to chemicals. As biological control agents, entomopathogenic nematodes (EPNs) attract attention increasingly in the research area recently. Results The aim of the study was to evaluate the pathogenicity of Pakistani isolates Steinernema bifurcatum and S. affine against the stored grain pests, Tribolium castaneum and Lasioderma serricorne, under laboratory conditions. Suspensions of nematodes were applied at 4 different concentrations 0, 50, 100, and 200 IJs/ml and 3 variable temperatures 15, 30, and 45°C. Pathogenicity rate was recorded after 48 h of application. The larval stage is found more susceptible than the adult. At 200 IJs, S. bifurcatum showed high mortality of L. serricorne larva (92%) and T. castaneum larva (93%), whereas S. affine showed 90 and 95% mortality of L. serricorne and T. castaneum larva, respectively, at 200 IJs. The results revealed that both species of EPN were able to control and reproduce on L. serricorne and T. castaneum. Maximum mortality was recorded at 45 °C from S. bifurcatum whereas S. affine at 15 °C. Conclusions Therefore, S. bifurcatum and S. affine could be suggested as a biological control agent for hot and cold climatic zones, respectively.

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

2004 ◽  
Vol 94 (12) ◽  
pp. 1305-1314 ◽  
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.

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

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
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.

scholarly journals Assessment of the Importance of Similarity in Carbon Source Utilization Profiles between the Biological Control Agent and the Pathogen in Biological Control of Bacterial Speck of Tomato

2002 ◽  
Vol 68 (9) ◽  
pp. 4383-4389 ◽  
Author(s):  
Pingsheng Ji ◽  
Mark Wilson
Keyword(s):  
Biological Control ◽  
Carbon Source ◽  
Disease Severity ◽  
Pseudomonas Syringae ◽  
Biological Control Agent ◽  
Carbon Sources ◽  
Control Agent ◽  
Carbon Source Utilization ◽  
Bacterial Speck

ABSTRACT Bacterial speck of tomato, caused by Pseudomonas syringae pv. tomato, was used to determine whether similarity in carbon source utilization between a preemptive biological control agent and the pathogen was significant in determining the ability of the bacterium to suppress disease. Similarity in carbon source utilization was quantified as the ratio of the number of tomato carbon sources utilized in vitro by the biological control agent to the number of tomato carbon sources utilized in vitro by the target pathogen (the niche overlap index [NOI]). Suppression of the disease was quantified as the percent reduction in disease severity compared to the pathogen-only control when nonpathogenic bacteria were applied to foliage 48 h prior to the pathogen. In the collection of 36 nonpathogenic bacterial strains, there was a significant (P < 0.01), but weak (r2 = 0.25), correlation between reduction in disease severity and similarity in carbon source utilization, suggesting that similarity in carbon source use was significant in determining ability to suppress disease. The relationship was investigated further using catabolic mutants of P. syringae strain TLP2, an effective biological control agent of speck. Catabolic mutants exhibited lower levels of similarity (NOI = 0.07 to 0.90) than did wild-type TLP2 (NOI = 0.93). With these catabolic mutants there was a significant (P < 0.01), and stronger (r2 = 0.42), correlation between reduction in disease severity and similarity in carbon source utilization. This suggests that similarity in carbon source utilization was a more important component of biological control ability for the catabolic mutants than for the nonpathogenic bacteria. Together, these studies indicate that suppression of bacterial speck of tomato was correlated with nutritional similarity between the pathogenic and nonpathogenic bacteria and suggest that preemptive utilization of carbon sources was probably involved in the biological control of the disease by both the naturally occurring nonpathogenic bacteria and the catabolic mutants.

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