scholarly journals Antagonism of Plant Pathogens by Calotropis procera

2021 ◽  
Vol 13 (4) ◽  
pp. 120
Author(s):  
Karla Danielle Nogueira Cardoso ◽  
Maria Josiane Martins ◽  
Thaisa Aparecida Neres de Souza ◽  
Isabelle Carolyne Cardoso ◽  
Patrícia Nirlane da Costa Souza ◽  
...  

Phomopsis sojae and Sclerotinia sclerotiorum are responsible for stem and pod dryness and white mold in soybean. These pathologies directly affect the quality of seeds/grains and compromise the entire plant. The use of extracts from different plants has been the subject of research for the control of several phytopathogens. Calotropis procera is among botanical species that synthesize efficient compounds for biocontrol. In this context, the aim of this study was to evaluate the in vitro effect of C. procera aqueous extract on P. sojae and S. sclerotiorum. The experiment was carried out in completely randomized blocks in a 2 × 5 factorial scheme (two fungi and five extract concentrations 0%, 5%, 10%, 15% and 20%) with 4 replicates. C. procera aqueous extract concentrations were added to Petri dishes containing PDA. After 48 hours, the mycelial growth rate was evaluated. After seven days of incubation, the fungal colony area, sporulation, and germination of P. sojae and S. sclerotiorum were evaluated. There was significant interaction between fungi × extract concentrations (p < 0.05) for all variables analyzed. The mycelial growth rate of P. sojae was lower than that of S. sclerotiorum. The diameter of the P. sojae fungal colony was smaller than that of S. sclerotiorum when concentrations of 5%, 10% and 15% were used. As the extract concentration increased, fungi sporulation and germination reduced.

Author(s):  
Luana Sabrine Silva ◽  
Edson Hiydu Mizobutsi ◽  
Gisele Polete Mizobutsi ◽  
Denilson Ferreira De Oliveira ◽  
Viviane Aparecida Costa Campos ◽  
...  

Aims: To evaluate the in vitro effect of mango peel extracts using different types of solvent and concentrations on the Colletotrichum gloeosporioides development. Study Design: Activities were aimed at evaluating the in vitro antifungal potential of mango peel extracts. Study Location and duration: The study was carried out at the Laboratory of Post-Harvest Pathology of Fruits and Vegetables - State University of Montes Claros and Laboratory of Natural Products, Department of Chemistry - Federal University of Lavras during October and December 2018. Methodology: ‘Palmer’ mango peel (Mangifera indica) was submitted to drying in oven and grinding. Subsequently, extracts were obtained in Soxhlet system, using methanol, ethyl acetate and hexane as solvents. The three extracts were tested in vitro at concentrations of 0.0; 0.25; 0.5; 1.0 and 2.0 mg/mL by adding them in culture medium against C. gloeosporioides, which was isolated from mango fruits with anthracnose symptoms. The effect of extracts and their respective concentrations on the mycelial growth rate and conidia production and germination was evaluated. The design was completely randomized in a 3 x 5 factorial arrangement with 5 replicates. Results: Increased extract concentrations caused reduction in the mycelial growth rate of the pathogen (R2 = 0.96). Both factors under study acted simultaneously in conidia production (P < 0.05), and the hexane extract presented better results for this analyzed variable. There was total germination inhibition (P < 0.05) when 1 mg/mL ethyl acetate extract and 2 mg/mL methanol and hexane extracts were used. Conclusion: Methanol, hexane and ethyl acetate mango peel extracts had inhibitory effect on the in vitro C. gloeosporioides development.


2015 ◽  
Vol 105 (9) ◽  
pp. 1183-1190 ◽  
Author(s):  
Mohammad Ali ◽  
Bosung Kim ◽  
Kevin D. Belfield ◽  
David Norman ◽  
Mary Brennan ◽  
...  

Application of nanoparticles for controlling plant pathogens is a rapidly emerging area in plant disease management, and nanoparticles synthesis methods that are economical and ecofriendly are extensively investigated. In this project, we investigated the potential of silver nanoparticles (AgNPs) synthesized with aqueous extract of Artemisia absinthium against several Phytophthora spp., which cause many economically important crop diseases. In in vitro dose-response tests conducted in microtiter plates, 10 µg ml−1 of AgNPs inhibited mycelial growth of P. parasitica, P. infestans, P. palmivora, P. cinnamomi, P. tropicalis, P. capsici, and P. katsurae. Detailed in vitro dose-response analyses conducted with P. parasitica and P. capsici revealed that AgNPs synthesized with A. absinthium extract were highly potent (IC50: 2.1 to 8.3 µg ml−1) and efficacious (100%) in inhibiting mycelial growth, zoospore germination, germ tube elongation, and zoospore production. Interestingly, AgNP treatment accelerated encystment of zoospores. Consistent with in vitro results, in planta experiments conducted in a greenhouse revealed that AgNP treatments prevented Phytophthora infection and improved plant survival. Moreover, AgNP in in planta experiments did not produce any adverse effects on plant growth. These investigations provide a simple and economical method for controlling Phytophthora with AgNP without affecting normal plant physiology.


2019 ◽  
Vol 74 (11-12) ◽  
pp. 811-818 ◽  
Author(s):  
Lingling Fan ◽  
Bilan Luo ◽  
Zhongfu Luo ◽  
Li Zhang ◽  
Judi Fan ◽  
...  

AbstractIn order to obtain novel bioactive compounds with significant antifungal activities, two series of 3-substituted phthalide derivatives were designed and synthesized via reduction, bromine substitution, and etherification. In addition, the antifungal activities of all target compounds against nine phytopathogenic fungi in vitro were tested by using the mycelial growth rate method at the concentration of 50 μg mL−1. Preliminary bioassay tests showed that some compounds exhibited more potent antifungal activities as compared with hymexazol. The preliminary structure-activity relationships (SARs) of all target compounds were also investigated.


Plant Disease ◽  
2005 ◽  
Vol 89 (7) ◽  
pp. 755-762 ◽  
Author(s):  
A. M. C. Schilder ◽  
O. Erincik ◽  
L. Castlebury ◽  
A. Rossman ◽  
M. A. Ellis

Seventy-five isolates of Phomopsis were obtained from grapes (Vitis spp.) with Phomopsis cane and leaf spot symptoms in Ohio, Michigan, New York, Pennsylvania, Maryland, and Ontario (Canada). Four isolates from California and one from Europe were also included in the study. Isolates were grouped on the basis of DNA sequences from intron regions in the translation elongation factor 1-α and calmodulin genes. According to DNA sequence comparisons with the type isolate, all isolates except two (OH-48 and CAL-5) were determined to be P. viticola, confirming the etiology of this disease in the Great Lakes region. Thirty representative isolates were evaluated for mycelial growth rate in vitro, conidial size, and pathogenicity on grapevine (Vitis interspecific hybrid ‘Seyval’) leaves and internodes. A subsample of 13 isolates was also evaluated for pathogenicity on fruit and rachises. All isolates of P. viticola caused disease on grape but differed in virulence. Among P. viticola isolates, virulence on leaves and internodes was positively correlated, and virulence on fruit and rachises was positively correlated, but there was no relationship between ratings on vegetative versus reproductive grape tissues. Some isolates that were not virulent on leaves or internodes were highly virulent on fruit and rachises and vice versa, indicating some specialization with respect to host tissues. However, differences were mostly of a quantitative nature, which makes it difficult if not impossible to assign biotypes. Among P. viticola isolates, virulence on fruit and rachises was positively correlated with mycelial growth rate in vitro. For the two isolates that were not P. viticola, the internal transcribed spacer regions of the nuclear ribosomal DNA were sequenced for identification purposes. Based on the best match available in GenBank, CAL-5 was determined to be close to Diaporthe phaseolorum, while the sequence of OH-48 matched that of Phomopsis sp. from Eucommia ulmoides in China. Both isolates had shorter alpha conidia and significantly higher mycelial growth rates than the P. viticola isolates, and were not or only slightly pathogenic to Vitis interspecific hybrid ‘Seyval’.


Planta Medica ◽  
2010 ◽  
Vol 76 (12) ◽  
Author(s):  
N Saowakon ◽  
P Chaichanasak ◽  
C Wanichanon ◽  
V Reutrakul ◽  
P Sobhon

2014 ◽  
Vol 45 (3) ◽  
pp. 861-872 ◽  
Author(s):  
P.C. Guadarrama-Mendoza ◽  
G. Valencia del Toro ◽  
R. Ramírez-Carrillo ◽  
F. Robles-Martínez ◽  
J. Yáñez-Fernández ◽  
...  

2011 ◽  
Vol 35 (1) ◽  
pp. 115-123 ◽  
Author(s):  
Ricardo Borges Pereira ◽  
Gilvaine Ciavareli Lucas ◽  
Fabiano José Perina ◽  
Mário Lúcio Vilela de Resende ◽  
Eduardo Alves

The objectives of this work were to assess the in vitro effect of essential oils extracted from cinnamon, citronella, lemon grass, India clove, tea tree, thyme, neem and eucalyptus on the conidia germination and on mycelial growth of Cercospora coffeicola, and their efficacy to control the brown eye spot in coffee seedlings (cultivars Catucaí 2SL, Catuaí IAC 62 and Mundo Novo 379/19) in a greenhouse, as well as their effects on the initial germination and infection events by scanning electron microscopy. All essential oils promoted the inhibition of conidia germination with increasing concentrations. India clove, cinnamon, neem, thyme and lemon grass oils inhibited the mycelial growth of C. coffeicola. The cinnamon and citronella oils were the most promising for brown eye spot control in all cultivars. In scanning electron microscopy, the cinnamon and citronella oils reduced germination and mycelial development of C. coffeicola in vivo, eight and 16 hours after inoculation, promoting, in some cases, the leakage of the cellular content. Essential oils of cinnamon and citronella reduced the incidence and severity of brown eye spot, in addition to presenting direct toxicity to the pathogen.


2010 ◽  
Vol 50 (1) ◽  
pp. 93-97 ◽  
Author(s):  

Effect of Fungal Metabolites and Amendments on Mycelial Growth ofRhizoctonia SolaniA shift towards organic farming suggests amalgamation of organic resources against soil borne plant pathogens. The influence of metabolites of most ubiquitousAspergillusspp., organic amendment extracts and their combined effect withTrichoderma virenswere evaluatedin vitroagainstRhizoctonia solani.The minimum (36.1 mm) growth was attained byR. solaniin co-culture withA. niger.The maximum (42.3 mm) inhibition of mycelial growth of the test organism was observed with culture filtrate ofA. ochraceousfollowed byA. niger, A. fumigatus, A. flavusandA. terreus.Among organic amendment extractants, castor cake exhibited an additive effect on the growth ofT. virens, however, the maximum (41.8 mm) suppressive effect onR. solaniwas observed with vermicompost. With the advance in time, the effect of organic amendment extracts increased markedly. Inhibition potential of culture filtrate mixturte ofA. niger+T. virensandA. ochraceous+T. virensagainstR. solaniwas significantly higher in comparison to the other combinations.


2017 ◽  
Vol 6 (9) ◽  
pp. 1676 ◽  
Author(s):  
Ramaraju Cherkupally ◽  
Srinivasa Reddy Kota ◽  
Hindumathi Amballa ◽  
Bhumi Narasimha Reddy

The antifungal activity of aqueous extracts of nine plants viz, Azadirachta indica, Parthenium hysterophorus, Momordica charantia, Allium sativum, Eucalyptus globules, Calotropis procera, Aloe vera, Beta vulgaris and Datura stramonium were assessed in vitro against Fusarium oxysporum f. sp. melongenae, Rhizoctonia solani and Macrophomina phaseolina, the soil borne phytopathogens. The assessment of fungitoxic effect was carried out by using three different concentrations i.e., 5, 10 and 20% against the test fungi, in terms of percentage of mycelial growth inhibition. The extract of A. sativum completely inhibited the mycelial growth of M. phaseolina at all the concentrations. The extracts of D. stramonium and E. globulus inhibited the mycelial growth of R. solani of 72%, and 70.7% respectively at 20% concentration, that of A. sativum, E. globulus and D. stramonium exhibited inhibition percentage of 63.3%, 61.8% and 61.1% respectively at 20% concentration on Fusarium oxysporum f. sp. melongenae. The application of plant extracts for disease management could be less expensive, easily available, non-polluting and eco-friendly.


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