scholarly journals Enhanced Antifungal Bioactivity of Coptis Rhizome Prepared by Ultrafining Technology

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Ping-Chung Kuo ◽  
Yao-Tung Lin ◽  
Mei-Lin Yang ◽  
Ming-Yuan Liao ◽  
Guo-Feng Chen ◽  
...  

The aim of this study was to identify and quantify the bioactive constituents in the methanol extracts of Coptis Rhizome prepared by ultrafining technology. The indicator compound was identified by spectroscopic method and its purity was determined by HPLC. Moreover, the crude extracts and indicator compound were examined for their ability to inhibit the growth ofRhizoctonia solaniKühn AG-4 on potato dextrose agar plates. The indicator compound is a potential candidate as a new plant derived pesticide to controlRhizoctoniadamping-off in vegetable seedlings. In addition, the extracts of Coptis Rhizome prepared by ultrafining technology displayed higher contents of indicator compound; they not only improve their bioactivity but also reduce the amount of the pharmaceuticals required and, thereby, decrease the environmental degradation associated with the harvesting of the raw products.

1999 ◽  
Vol 45 (5) ◽  
pp. 389-395 ◽  
Author(s):  
S Kumar ◽  
K Sivasithamparam ◽  
J S Gill ◽  
M W Sweetingham

Rhizoctonia solani anastomosis group (AG) 11 causes serious damping-off and hypocotyl rot of lupins (Lupinus angustifolius L.) and is wide-spread in the northern grain-belt of Western Australia. We compared growth of AG-11 to AG-8, which causes bare-patch of grain crops including lupin. AG-11 grew significantly faster than AG-8 on potato dextrose agar (PDA) at several temperatures (10, 15, 20, 25, or 30°C) and also grew best within the pH range of 4-7. Growth of AG-8 was best at pH 7. There was no difference in the linear growth in soil of both AGs at 10°C, but AG-11 grew at a significantly faster rate at 20°C. Reduction in growth of AG-11 on osmotically adjusted PDA at temperatures between 10 and 30°C was more pronounced than that of AG-8. AG-11 caused very little lupin pre-emergence damping-off and hypocotyl rot at 10°C, and most severe hypocotyl rot was recorded at 20 and 25°C. Severity of hypocotyl rot caused by AG-11 at soil water potentials of -0.1, -0.07, and -0.05 MPa was higher than at -0.03 MPa. It appears that AG-11 is well suited to the environmental conditions of the relatively small area in Western Australia from which it is readily isolated.Key words: Rhizoctonia solani, anastomosis groups, osmotic potential, lupin.


2006 ◽  
Vol 96 (12) ◽  
pp. 1372-1379 ◽  
Author(s):  
Masahiro Kasuya ◽  
Andriantsoa R. Olivier ◽  
Yoko Ota ◽  
Motoaki Tojo ◽  
Hitoshi Honjo ◽  
...  

Suppressive effects of soil amendment with residues of 12 cultivars of Brassica rapa on damping-off of sugar beet were evaluated in soils infested with Rhizoctonia solani. Residues of clover and peanut were tested as noncruciferous controls. The incidence of damping-off was significantly and consistently suppressed in the soils amended with residues of clover, peanut, and B. rapa subsp. rapifera ‘Saori’, but only the volatile substance produced from water-imbibed residue of cv. Saori exhibited a distinct inhibitory effect on mycelial growth of R. solani. Nonetheless, disease suppression in such residue-amended soils was diminished or nullified when antibacterial antibiotics were applied to the soils, suggesting that proliferation of antagonistic bacteria resident to the soils were responsible for disease suppression. When the seed (pericarps) colonized by R. solani in the infested soil without residues were replanted into the soils amended with such residues, damping-off was suppressed in all cases. In contrast, when seed that had been colonized by microorganisms in the soils containing the residues were replanted into the infested soil, damping-off was not suppressed. The evidence indicates that the laimosphere, but not the spermosphere, is the site for the antagonistic microbial interaction, which is the chief principle of soil suppressiveness against Rhizoctonia damping-off.


Sugar Tech ◽  
2021 ◽  
Author(s):  
Md Ehsanul Haque ◽  
Dilip K. Lakshman ◽  
Aiming Qi ◽  
Mohamed F. R. Khan

2021 ◽  
Vol 16 (7) ◽  
pp. 15-22
Author(s):  
Paul Giftson ◽  
Jerrine Joseph ◽  
Revathy Kalyanasundaram ◽  
V. Ramesh Kumar ◽  
Wilson Aruni

Tuberculosis (TB) is a communicable disease and remains one of the top 10 causes of death worldwide. One fourth of the world population is infected with TB at a risk of developing disease. The increase in the incidence of drug resistant TB around the world urges the need to develop a new candidate to fight against the disease. Plants were considered as the rich source of bioactive components to be used as potential drugs. Medicinal plants are used in pure as well as crude materials for their medicinal properties. Our research aims in identifying the phyto-molecules which have anti- tuberculosis property. Four medicinal plants namely, Acalyphaciliata (Kuppaimeni), Solanumtrilobatum (Thuthuvalai), Momordicacharantia (Bitter Gourd) and Sennaauriculata (Avaram) were chosen to evaluate their antimicrobial activity focusing on anti-tubercular activity. The methanol extracts of the medicinal plants showed significant inhibitory activity against bacterial and fungal pathogens. Sennaauriculata methanol extracts showed activity against S. aureus, E. coli, P. aeruginosa and C. albicans. In the screening of antimycobacterial activity done by LRP assay, among the plant extracts tested, the hexane crude extracts of Momordicacharantia (Bitter Gourd) showed 82.2% and 81.03% of inhibition against M. tuberculosis H37Rv at 500µg/ml and 250µg/ml concentration respectively. Similarly, the methanol crude extracts of Momordicacharantia showed 87.14% and 63.55% of inhibition at 500µg/ml and 250µg/ml concentration respectively.


2018 ◽  
Vol 40 (1) ◽  
pp. 35075 ◽  
Author(s):  
Alexandre Dinnys Roese ◽  
Paulo Justiniano Ribeiro Junior ◽  
Vanderley Porfírio-da-Silva ◽  
Louise Larissa May De Mio

Plant Disease ◽  
2016 ◽  
Vol 100 (12) ◽  
pp. 2427-2433 ◽  
Author(s):  
Sahar Arabiat ◽  
Mohamed F. R. Khan

Rhizoctonia damping-off and crown and root rot caused by Rhizoctonia solani are major diseases of sugar beet (Beta vulgaris L.) worldwide, and growers in the United States rely on fungicides for disease management. Sensitivity of R. solani to fungicides was evaluated in vitro using a mycelial radial growth assay and by evaluating disease severity on R. solani AG 2-2 inoculated plants treated with fungicides in the greenhouse. The mean concentration that caused 50% mycelial growth inhibition (EC50) values for baseline isolates (collected before the fungicides were registered for sugar beet) were 49.7, 97.1, 0.3, 0.2, and 0.9 μg ml−1 and for nonbaseline isolates (collected after registration and use of fungicides) were 296.1, 341.7, 0.9, 0.2, and 0.6 μg ml−1 for azoxystrobin, trifloxystrobin, pyraclostrobin, penthiopyrad, and prothioconazole, respectively. The mean EC50 values of azoxystrobin, trifloxystrobin, and pyraclostrobin significantly increased in the nonbaseline isolates compared with baseline isolates, with a resistant factor of 6.0, 3.5, and 3.0, respectively. Frequency of isolates with EC50 values >10 μg ml−1 for azoxystrobin and trifloxystrobin increased from 25% in baseline isolates to 80% in nonbaseline isolates. Although sensitivity of nonbaseline isolates of R. solani to quinone outside inhibitors decreased, these fungicides at labeled rates were still effective at controlling the pathogen under greenhouse conditions.


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