scholarly journals Pathogenicity of Burkholderia cepacia (Pseudomonas cepacia) in four onion genotypes (Allium sp.)

1969 ◽  
Vol 80 (3) ◽  
pp. 123-134
Author(s):  
Rodrigo O. Campo ◽  
Mildred Zapata
Keyword(s):  
Puerto Rico ◽  
Burkholderia Cepacia ◽  
Biological Control Agent ◽  
Control Agent ◽  
Phytopathogenic Fungi ◽  
Pseudomonas Cepacia ◽  
Randomized Design ◽  
Sour Skin ◽  
Different Levels ◽  
Yellow Onion

Onion is one of the major crops in Puerto Rico.The bacterium Burkholderia cepacia (basonym: Pseudomonas cepacia) is the causal agent of the onion disease sour skin. In Puerto Rico the strain B. cepacia UPR-5C has been reported as a biological control agent of various phytopathogenic fungi. At present, the pathogenic characteristics of this strain are unknown. The pathogenicity of B. cepacia UPR-5C was determined in four commercial onion genotypes, yellow, red scailions, white Spanish and slip, by using a complete randomized design with split plots. The onion genotypes were inoculated with bacteria of 10e CFU/ml from each growth phase and with the filtrates corresponding to each phase. Symptoms were evaluated seven days after inoculation.Treatments with cells, but not filtrates, induced symptoms in the yellow onion genotype. The red, white and slip genotypes were not susceptible, but the bacterium is pathogenic to yellow onions. There are, however, different levels of resistance within the species.

ENHANCEMENT OF GROWTH OF ONION (ALLIUM CEPA L.) BY BIOLOGICAL CONTROL AGENT TRICHODERMA SPP

2001 ◽  
Vol 49 (4) ◽  
pp. 393-395 ◽  
Author(s):  
E. PAYGHAMI ◽  
S. MASSIHA ◽  
B. AHARY ◽  
M. VALIZADEH ◽  
A. MOTALLEBI
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Trichoderma Viride ◽  
Control Agent ◽  
White Rot ◽  
Trichoderma Spp ◽  
Sclerotium Cepivorum ◽  
Randomized Design ◽  
Allium Cepa L ◽  
Significant Difference

The effect of Trichoderma harzianum and Trichoderma viride (isolated from mycoflora in the rhizosphere of onion) in increasing the growth of onion was studied in a completely randomized design in pots with 12 replications under greenhouse conditions at 21°C with a 12-h light/dark cycle (fluorescent and incandescent lighting). The biological control of Sclerotium cepivorum Berk, the causal agent of white rot of onion, was also investigated in this experiment. The addition of Trichoderma spp. to autoclaved soil (inoculation of 2/3 of the top soil in the pots with 4% (v/v) inoculum of T. harzianum and T. viride) significantly increased the growth and fresh weight of the onion plants (P=1%). The biological control of S. cepivorum was achieved with T. harzianum and T. viride, but no significant difference was observed between the two species.

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 POTENTIAL IMPACT OF METARHIZIUM ANISOPLIAE ON THE DIAMONDBACK MOTH (LEPIDOPTERA: PLUTELLIDAE) AND ITS PARASITOID DIADEGMA SEMICLAUSUM (HYMENOPTERA: ICHNEUMONIDAE)

2009 ◽  
Vol 9 (2) ◽  
pp. 99-108
Author(s):  
Rosma Hasibuan ◽  
Nilly Christalia ◽  
F.X. Susilo ◽  
Nur Yasin
Keyword(s):  
Metarhizium Anisopliae ◽  
Biological Control Agent ◽  
Diamondback Moth ◽  
Adult Emergence ◽  
Control Agent ◽  
Conidial Suspension ◽  
Diadegma Semiclausum ◽  
Randomized Design ◽  
Potential Impact ◽  
And Control

Potential Impact of Metarhizium anisopliae on the Diamondback Moth (Lepidoptera: Plutellidae) and Its Parasitoid Diadegma semiclausum (Hymenoptera: Ichneumonidae).  Laboratory studies were conducted to evaluate the effect of the Metarhizium anisopliae against the diamondback moth, Plutella xylostella and its parasitoid, Diadegma  semiclausum. A completely randomized design consisted of 5 treatments (4 concentrations of conidial suspension: 5 x 104, 3.5 x 105, 2.5 x 106, 1.2 x 107 conidia/ml and control) was used.  The results indicated that the mortality of P. xylostella larvae were significantly induced by the fungal treatments.  A significant reduction in pupation and adult emergence of P. xylostella was also detected in all treatments when compared with that in the control. The fungus might also result in a male-biased sex ratio of the surviving P. xylostella. When applied at a concentration of 1.2 x 107 conidia/ml, M.  anisopliae might significantly reduce the survival of the parasitoid, D. semiclausum. Thus, despite its potential as a biological control agent against P. xylostella, the entomomogenous fungus M. anisopliae was also detrimental to the larvae parasitoid D. semiclausum.

scholarly journals Rhizosphere Streptomyces formulas as the biological control agent of phytopathogenic fungi Fusarium oxysporum and plant growth promoter of soybean

2021 ◽  
Vol 22 (6) ◽  
Author(s):  
MAYA SARI ◽  
ABDJAD ASIH NAWANGSIH ◽  
Aris Tri Wahyudi
Keyword(s):  
Biological Control ◽  
Plant Growth ◽  
Fusarium Oxysporum ◽  
Biological Control Agent ◽  
Control Agent ◽  
Phytopathogenic Fungi ◽  
Disease Suppression ◽  
Growth Promoter ◽  
Sterile Soil ◽  
Plant Growth Promoter

Abstract. Sari M, Nawangsih AA, Wahyudi AT. 2021. Rhizosphere Streptomyces formulas as the biological control agent of phytopathogenic fungi Fusarium oxysporum and plant growth promoter of soybean. Biodiversitas 22: 3015-3023. Rhizosphere Streptomyces are considered as promising sources of plant growth-promoting rhizobacteria (PGPR) and biocontrol agents against pathogenic fungi, particularly Fusarium oxysporum causing root rot, cotyledon rot, hypocotyl rot, and stunted growth in soybean. Formulation of rhizosphere Streptomyces with appropriate carrier materials is necessary to facilitate storage and application in plants. This study aimed to develop a formulation of rhizosphere Streptomyces, apply the formula to control F. oxysporum, and promote soybean plant growth. Five Streptomyces isolates, i.e., Streptomyces panaciradicis ARK 13, Streptomyces tritolerans ARK 17, Streptomyces recifensis ARK 63, Streptomyces tendae ARK 91, and Streptomyces manipurensis ARK 94 were used in this study. All of the isolates could grow in potato broth, rice bran extract, and molasses as alternative media. The highest biomass produced from the molasses growth medium. All five isolates had antifungal activity against F. oxysporum with the inhibition percentage ranging from 41% to 76%, and all of them were detected to have the iaaM gene. Indole-3-acetic acid (IAA) hormone produced by these isolates were ranging from 8.99-15.14 mg L-1, with the phosphate solubilization index of 2.13-2.47. Five rhizosphere Streptomyces formulas with the main carrier of peat could maintain the viability with the population density of 108 CFU g-1 for 8 weeks of storage at room temperature. Two formulas, F17 and F94, were the best formulas to control disease caused by F. oxysporum with disease suppression of 74% in sterile soil and 80-85% in non-sterile soil. Formula F17 and F94 significantly increased soybean growth in sterile and non-sterile soils. Therefore, these formulas could be recommended as biocontrol and plant growth promoters of soybean.

Colombian population of the mite Gaeolaelaps aculeifer as a predator of the thrips Frankliniella occidentalis and the possible use of an astigmatid mite as its factitious prey

2018 ◽  
Vol 23 (12) ◽  
pp. 2359 ◽  
Author(s):  
Diana M Rueda-Ramirez ◽  
Diana M Rios-Malaver ◽  
Amanda Varela-Ramirez ◽  
Gilberto J. de Moraes
Keyword(s):  
Mass Production ◽  
Frankliniella Occidentalis ◽  
Biological Control Agent ◽  
Western Flower Thrips ◽  
Predation Rate ◽  
Control Agent ◽  
Small Scale ◽  
Generalist Predator ◽  
Randomized Design ◽  
Factitious Prey

Gaeolaelaps aculeifer (Canestrini) is a well-known generalist predator currently commercialized to control several edaphic organisms, including Diptera larvae and thrips pre-pupae and pupae. The recent detection of this species in the Bogotá plateau of Colombia raised the interest to investigate details about the biology of this new population and evaluate its potential as a biological control agent for use in that country against Frankliniella occidentalis Pergande (Thripidae), the western flower thrips. The objective of this study was to evaluate experimentally the biological characteristics of the Colombian population of G. aculeifer and its predation capacity on F. occidentalis, as well as the possibility to use a factitious prey for its mass production or as complementary food in predator field releases. The study was conducted with three diets: F. occidentalis (T), Aleuroglyphus ovatus (A), and A. ovatus + F. occidentalis (TA), in a randomized design experiment using G. aculeifer females. Predation rate was about 2.6 pre-pupae/pupae of F. occidentalis/female/day when only thrips was available as prey, reducing to 2.0 when thrips was combined with A. ovatus. Oviposition was the same when fed each of those prey and their combination (2.5–2.9 eggs/female/day). Some differences between diets were observed for duration of some periods of the life cycle, but no differences were observed for life table parameters. The greatest differences observed between this population and what has been reported for other populations of the same predator (evaluated when feeding other prey) refer to duration of deutonymphal period and Ro (respectively longer and higher in the former). It is concluded that the Colombian population is able to feed, develop, and reproduce on pre-pupae and pupae of F. occidentalis and that A. ovatus can be used for its small scale mass production and as a complementary diet in predator field releases.

scholarly journals Potensi Beauveria bassiana sebagai Agens Hayati Spodoptera litura Fabr. pada Tanaman Kedelai

Agrikultura ◽  
2018 ◽  
Vol 29 (1) ◽  
pp. 43
Author(s):  
Ayu Rosmiati ◽  
Cecep Hidayat ◽  
Efrin Firmansyah ◽  
Yati Setiati
Keyword(s):  
Biological Control ◽  
Beauveria Bassiana ◽  
Spodoptera Litura ◽  
Biocontrol Agent ◽  
Biological Control Agent ◽  
Control Agent ◽  
Spore Density ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Spore Densities

ABSTRACTThe Potency of Beauveria bassiana as a biological control agent of Spodoptera lituraThe attack of Spodoptera litura can result in the decrease of soybean yield, so that the soybean production cannot fulfill the demand of soybean. The objective of the study was to examine the potency of Beauveria bassiana as a biological control agent of Spodoptera litura. The research was conducted at the Pest Laboratory, Departement of Agrotechnology, UIN Sunan Gunung Djati Bandung from January to March 2017. The research was carried out using Completely Randomized Design (RBD) with six treatments of B. bassiana spore density and four replications. The treatments were spore densities of 100 (control), 102, 104, 106, 108, and 1010/ml aquades that applied to the instar II of S. litura larvae. The advanced test used was Duncan's advanced test of 5%. The results showed that the B. bassiana density spore of 1010/ml aquades caused the highest S. litura larvae mortality of 82.50% and the lowest weight of food eaten by S. litura larvae of 0.79 g.Keywords: Biocontrol Agent, Beauveria bassiana, Spodoptera litura, SoybeanABSTRAKSerangan Spodoptera litura dapat menurunkan hasil tanaman kedelai, sehingga produksi tanaman kedelai belum bisa memenuhi permintaan kedelai di Indonesia. Tujuan penelitian ini untuk menguji patogenitas Beauveria bassiana sebagai agens hayati pengendali Spodoptera litura. Penelitian dilaksanakan di Laboratorium Hama Jurusan Agroteknologi, UIN Sunan Gunung Djati Bandung dari Januari sampai Maret 2017, menggunakan Rancangan Acak Lengkap (RAL) dengan enam perlakuan kerapatan spora B. bassiana dan empat ulangan. Perlakuan tersebut adalah kerapatan spora 100 (kontrol), 102, 104, 106, 108, dan 1010/ml aquades yang diaplikasikan pada larva S. litura instar II. Uji lanjut yang digunakan adalah Uji lanjut Duncan taraf 5%. Hasil penelitian menunjukkan bahwa kerapatan spora B. bassiana 1010 /ml aquades menyebabkan mortalitas larva S. litura sebesar 82,50% dan bobot pakan yang dimakan oleh larva S. litura paling rendah sebesar 0,79 g.Kata Kunci: Agens hayati, Beauveria bassiana, Spodoptera litura, Kedelai

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 Association of L-form Bacteria with Plants and their Application in Biological Control of Phytopathogenic Fungi and Bacteria: A Review

2021 ◽  
pp. 77-86
Author(s):  
P. W. H. K. P. Daulagala
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Control Agent ◽  
Phytopathogenic Fungi ◽  
Plant Diseases ◽  
World Population ◽  
Wide Range ◽  
Rigid Cell Wall ◽  
Plant Disease Management ◽  
Phytopathogenic Fungi And Bacteria

L-form bacteria with modified or no cell walls are a special group of bacteria derived or induced from cell walled forms following suppression of their rigid cell wall. They have been used to establish non-pathogenic symbioses with a wide range of plants. These L-form-plant symbioses have been shown to confer resistance against the subsequent challenge of the associated plants by both fungal and bacterial pathogens. As the world population increases, the demand for food also increases and hence control of plant diseases is of paramount importance in producing enough agricultural crops to fulfil the food demand. Plant disease management using chemical fungicides and pesticides etc. is not an ecofriendly approach and hence researchers look for alternative options such as the use of biocontrol agents which are ecofriendly and sustainable. This review paper highlights the published information on the potential of applying L-form bacteria as a biological control agent in management of plant diseases caused by pathogenic microorganisms.

scholarly journals Lytic Enzymes of Aspergillus piperis as a Tool for Attacking Some Phytopathogenic Fungi In vitro with Special Reference to its Cytotoxicity

2021 ◽  
Author(s):  
Samah Abd El-Kader El-Debaiky ◽  
Anwer S.M. El-Badry
Keyword(s):  
Cell Line ◽  
Biological Control Agent ◽  
Control Agent ◽  
Phytopathogenic Fungi ◽  
Antagonistic Activity ◽  
Lytic Enzyme ◽  
Lytic Enzymes ◽  
Wi38 Cell ◽  
Ic50 Values

The antagonistic activity of Aspergillus piperis against Fusarium oxysporum f. sp. fabae (FOF) and Sclerotinia sclerotiorum were examined and showed multiple signs of hyphal interactions. Microscopic examination of contact regions among A. piperis and each pathogen revealed distinct enzymatic lysis of pathogenic hyphal cell walls. Therefore, it is important to estimate the lytic enzyme activity of A. piperis. Extracellular lytic enzymes are important offensive forces for A. piperis as a biological control agent. Chitinase, phospholipase, and protease recorded relatively high activity from a culture age of 10 days (82.3, 42.4, and 6.2 U/ml, respectively). Enzymatic persistence was measured at room temperature, recording relatively long periods, saving 54%, 46%, and 21% of their activity, respectively. The cytotoxicity of the crude culture filtrate of A. piperis was examined in MCF7 and WI38 human cell lines. The cell viability (IC50) value of the fungal filtrate was estimated after 24 h and 48 h. The results revealed that IC50 values against the MCF7 cell line were inoperative after 24 h and were recorded 80 μg/ml after 48 h. In contrast, IC50 values against the WI38 cell line were 85.69 and 69.8 μg/ml after 24 and 48 h, respectively.

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