Browsing by Author "Amitabh Singh"

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Antibiotic potential of plant growth promoting rhizobacteria (PGPR) against Sclerotium rolfsii
(2012) Amitabh Singh; Sudarshan Maurya; Rashmi Singh; U.P. Singh
High performance liquid chromatographic (HPLC) analysis of culture filtrates of plant growth promoting rhizobacteria (PGPR) and medium of inhibitory zone of interaction of Sclerotium rolfsii with PGPR, viz. Pseudomonas aeruginosa, Pseudomonas fluorescens 4, Pseudomonas fluorescens 4 (new) and Pseudomonas sp. varied from sample to sample. In all the culture filtrates of PGPRs, P. aeruginosa had nine phenolic acids in which ferulic acid (14.52 μg/ml) was maximum followed by other phenolic acids. However, the culture filtrates of P. fluorescens 4 had six phenolic acids with maximum ferulic acid (20.54 μg/ml) followed by indole acetic acid (IAA), caffeic, salicylic, o-coumeric acid and cinnamic acids. However, P. fluorescens 4 culture filtrate had seven phenolic acids in which salicylic acid was maximum (18.03 μg) followed by IAA, caffeic, vanillic, ferulic, o-coumeric and cinnamic acids. Pseudomonas sp. also showed eight phenolic acids where caffeic acid (2.75 μg) was maximum followed by trace amounts of ferulic, salicylic, IAA, vanillic, cinnamic, o-coumeric and tannic acids. The analysis of antibiosis zone of PGPRs showed fairly rich phenolic acids. A total of nine phenolic acids were detected in which caffeic acid was maximum (29.14 μg/g) followed by gallic (17.64 μg/g) and vanillic (3.52 μg/g) acids but others were in traces. In P. aeruginosa, antibiosis zone had seven phenolic acids where IAA was maximum (3.48 μg/g) followed by o-coumeric acid (2.08 μg/g), others were in traces. The medium of antibiosis zone of P. fluorescens 4 and P. fluorescens 4 new had eight phenolic acids in which IAA was maximum with other phenolic acids in traces. © 2012 Copyright Taylor and Francis Group, LLC.
Antifungal activity of neem (Azardirachta indica) toddy
(2010) U.P. Singh; S. Maurya; Amitabh Singh; Mandavi Singh
Neem (Azardirachta indica) is regarded as 'village pharmacy' in India due to its enormous use in the Indian villages as a folk medicine. Its different parts have been explored scientifically, except 'Neem toddy', which is a white secretion that exudes from the angle formed between the two major branches of old neem trees. The exact age of the tree upon the secretion of this white fluid is not known, nor why such a secretion occurs. It is normal, though rare, for such secretions to occur in old trees. The taste of neem toddy is bitter. The white milky liquid secretion, the 'neem toddy', was collected from the tree and assayed for the presence of phenolic acids by high performance liquid chromatography (HPLC). The phenolic acids detected were caffeic, vanillic, o-coumaric, cinnamic and salicylic acids. It was further fractionated by ethyl acetate and this fraction was tested against some fungi for antifungal activity. It was observed to be highly antifungal in vitro. Field experiments also showed its high efficacy against balsam (Impatiens balsamina) powdery mildew (Erysiphe cichoracearum). © 2010 Taylor & Francis.
Antifungal activity of the mixture of quaternary alkaloids isolated from Argemone mexicana against some phytopathogenic fungi
(2010) Sarita Singh; Amitabh Singh; Jyostana Jaiswal; T.D. Singh; V.P. Singh; V.B. Pandey; Aparna Tiwari; U.P. Singh
The anti-fungal activity of a mixture of quaternary alkaloids of Argemone mexicana was observed at different concentrations (1000, 2000, 3000, 4000 and 5000 μl/ml) against 10 fungi, viz., Ustilago cynodontis, Cercospora cajani, Sphaerotheca sp., Cercospora sp., Alternaria solani, Bipolaris sp., Helminthosporium sp., Curvularia sp., Fusarium udum and Alternaria cajani. Spore germination was inhibited at 2000, 3000, 4000, 5000 μg/ml. Analysis of phenolics by high performance liquid chromatography (HPLC) recorded 11 peaks in the alkaloids but only three could be identified, viz., tannic, caffeic and ferulic acids. The significant efficacy of the alkaloid under in vitro conditions may open the possibility of its use by farmers under field conditions for controlling some crop diseases. © 2010 Taylor & Francis.
Antifungal activity of two alkaloids of Zephyranthes citrina and their field efficacy against powdery mildew (Erysiphe cichoracearum) of balsam
(2010) Udai P. Singh; Leena Gohain; Sudarshan Maurya; Amitabh Singh; Vidya B. Pandey; Ashok K. Singh
The anti-fungal activity of two alkaloids isolated from bulbs of Zephyranthes citrina was observed against 10 fungi, viz, Aternaria solani, A. triticina, Curvularia lunata, C. maculuns, Cercospora malvacearum, Erysiphe sp., Fusarium udum, Helminthosporium pisi, H. speciferum and Ustilago cynodontis. Different concentrations (200, 400, 600, 800, 1000 μg/ml of alkaloids (A and B) were used. Spore germination was inhibited at 600, 800, 1000 μg/ml. B alkaloid was used against Erysiphe cichoracearum causing powdery mildew in balsam (Impatiens balsamina) in the field as pre-and post-inoculation treatments at 1000, 1500, 2000 μg/ml doses. The extract was effective in both pre-and post-inoculation treatments. Foliar application of this alkaloid resulted in inducing synthesis of phenolic acid in the leaves of balsam. Maximum phenolics were detected in the leaves treated with 1500 μg/ml in both pre-and post-inoculation treatments. The increase in the production of phenolics in treated leaves of balsam can be correlated with the induction of resistance in treated plants against powdery mildew. The significant efficacy of the alkaloid under field conditions opens the possibility of its use by farmers for also controlling other diseases. © 2010 Taylor & Francis.
Antifungal efficacy of some ethyl acetate extract fractions of Cyperus rotundus rhizomes against spore germination of some fungi
(Taylor and Francis Ltd., 2011) Amitabh Singh; S. Maurya; Rashmi Singh; U.P. Singh
Plant products play an important role as safe and ecofriendly method in controlling various plant diseases. Ethyl acetate fractions of Cyperus rotundus rhizomes have been found highly effective against some species of Alternaria (A. alternata, A. brassicola, A. solani, Alternaria chearanthi), Colletotrichum (C. musae, Colletotrichum sp.), Curvularia (C. lunata, C. maculans, C. pallescens, C. pennisetti), Helminthosporium (H. pennissetti, H. spiciferum, H. echinoclova and Heterosporium colocasiae) in vitro. A. brassisicola was highly sensitive to all the fractions at all the concentrations. Fractions 4-7 inhibited complete spore germination at 2000 and 3000 μg/ml as compared to control. However, 100% spore germination inhibition was found in Colletotrichum species in all the fractions at 2000 and 3000 μg/ml but at lower concentrations 50-60% spore germination and 90% reduction of germ tube elongation were observed. Curvularia species was highly sensitive to all concentrations of all the fractions as 50-100% spore germination inhibition was recorded at 500 μg/ml dose. Some species of Helminthosporium were sensitive at 3000 μg/ml in some fractions but other test fractions showed least efficacy. Fractions 4-7 were 100% inhibitory for H. colocasiae. Germ tube elongation was also affected by 60-90%. The germ tube branching and their elongation were affected in almost all species at 30 to 95%. The high efficacy of ethyl acetate fractions of rhizomes of C. rotundus against some fungi indicates that they can be very well tried under field conditions against some important plant diseases as an ecofriendly method of plant disease control. © 2011 Copyright Taylor and Francis Group, LLC.
Antimicrobial efficacy, disease inhibition and phenolic acid-inducing potential of chloroform fraction of cow urine
(2012) Udai Pratap Singh; Sudarshan Maurya; Amitabh Singh; Gopal Nath; Mandavi Singh
High-performance liquid chromatographic (HPLC) analysis of chloroform fraction (CF) of cow urine showed rich pool of phenolic acids. Antifungal and antibacterial bioassays of CF have shown its tremendous efficacy against some fungal plant pathogens as well as human pathogenic bacteria at very low concentrations. The CF also inhibited powdery mildew (Erysiphe cichoracearum) of balsam (Impatiens balsamania) under field conditions during pre- and post-inoculation treatments. HPLC analysis of pre- and post-inoculation-treated plant leaves indicated that CF induced phenolic acid synthesis as compared to control. The results revealed that CF of cow urine has the potential for controlling some important human diseases. The result on balsam powdery mildew is a good signal that CF may also be effective against other plant diseases in the field. © 2012 Copyright Taylor and Francis Group, LLC.
Assessment of Bacillus licheniformis (vbr-1) against phytopathogenic fungi and its plant growth-promoting effect on wheat
(2009) Shrilekha Mishra; Rashmi Srivastava; Amitabh Singh; B.K. Sarma; U.R. Singh
The microorganisms have established themselves as an effective alternative to control plant pathogens. There are many examples of formulations using bacterial or fungal strains for biocontrol applications. Bacillus licheniformis (isolate vbr-1) which has been used in the present experiment showed antagonistic activity against several fungi viz., Sclerotium rolfsii Sacc., Curvularia lunata (Walk.) Boedijn, Bipolaris oryzae (Breda de Haan), Fusarium udum Butler, Macrophomina phaseolina (Tassi) Goid, Sclerotinia sclerotiorum (Lib.) de Bary, Aspergillus flavus Link ex Fr., and Alternaria alternata (Fr.) Keissl when tested in dual culture technique. The ethanolic extract of test bacteria have revealed antifungal compounds of different Rf values in TLC. The bacterial culture extract also stimulated growth of wheat seedlings. The in vitro results of the experiments revealed that this bacterium may prove worthy for protecting plants from fungal infection. Its plant growth-promoting property is an additional factor in increasing crop yields. The leaves obtained from the treated and untreated wheat seeds with bacterial extract showed high amount of phenolic acids in the former as compared to control, when analyzed through High Performance Liquid Chromatography (HPLC).
Foliar spray of aqueous extract of neem (azadirachta indica) cake to control balsam (Impatiens balsaminia) powdery mildew
(2010) U.P. Singh; S. Maurya; Amitabh Singh; Leena Gohain
Neem cake is used as a soil amendment. It releases nutrient into the soil very slowly. It is also an insect repellent. It improves the physical as well as biological conditions of the soil such as soil aeration, water holding capacity and also the microflora in the rhizosphere. Aqueous extract of neem cake was used against powdery mildew (Erysiphe cichoracearum) of balsam (Impatiens balsaminia) in the field at 25, 50, 75 and 100%. The efficacy was observed even at low concentrations (25%). Foliar application of aqueous extract of neem cake induced synthesis of phenolic acids in balsam. Maximum phenolic acid was detected in balsam plant leaves treated with 50% neem cake followed by 75% in both pre-and post-inoculation treatments. The induction of phenolic acid in plants was correlated with the induction of resistance in treated plants against powdery mildew. © 2010 Taylor & Francis.
Fungal spore germination inhibition by alkaloids dehydrocorydalmine and oxyberberine
(2009) Amitabh Singh; Sarita Singh; Sushma Singh; Tryambak Dev Singh; Virendra Pratap Singh; Vidya Bushan Pandey; Udai Pratap Singh
The alkaloids dehydrocorydalmine and oxyberberine isolated from Argemone mexicana were assessed against spore germination of some fungi, e.g., Alternaria cajani, Bipolaris sp., Helminthosporium sp., Fusarium udum and Curvularia sp. While dehydrocorydalmine inhibited 100% spore germination of the fungi Helminthosporium sp. and Curvularia sp. at 5 000 ppm, oxyberberine showed similar activity against spore germination of Bipolaris sp. and Curvularia sp. All the five fungi were significantly inhibited at 1 000 to 5 000 ppm concentrations.
Germination responses of fungal spores to magnetically restructured water
(Informa Healthcare, 1994) Subas Rai; U.P. Singh; K.P. Singh; Amitabh Singh
The effect of magnetically restructured water was examined on spore germination of some fungi. Restructuring of water was done by exposing the water samples separately to dipoles of a 0.3 T permanent magnet for variable lengths of time. Spore germination of some fungi was observed by mixing the spores in a drop of restructured water samples on separate depression glass slides and incubating the slides for 24 h at 27 ± 2°C. Fungal spores for the present study were obtained from freshly grown cultures of Alternaria alternata, A. carthami, A. mali, A. sesamicola, Aspergillus niger, A. terreus, Fusarium liniand Helminthosporium sativum on potato dextrose Difco powder agar medium. This study reveals that changes in water structure produced by different lengths of exposure by different magnetic poles (of a permanent magnet) differentially inhibit spore germination of various fungi. The varying inhibitory effects of water exposed to different magnetic poles indicates the possible existence of magnetic-pole memory in water. © 1994 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.
Induction of sexual reproduction in Sclerotium rolfsii, Ustilago cynodontis, and Cintractia limitata by Cyperus rotundus rhizomes
(National Research Council of Canada, 1996) U.P. Singh; B. Prithiviraj; S. Khiste; S. Dalai; Amitabh Singh
Cyperus rotundus rhizomes induced sexual states in three fungi belonging to different genera, viz. Sclerotium rolfsii, Ustilago cynodontis, and Cintractia limitata. Rhizome meal and methanolic extract induced the formation of the sexual state in S. rolfsii while aqueous extract of Cyperus rotundus was most effective in inducing sexual reproduction in U. cynodontis and Cintractia limitata.
Jatrorrhizine and columbamine alkaloids isolated from Argemone mexicana are inhibitory to spore germination of some plant pathogenic fungi
(2010) Amitabh Singh; Sarita Singh; Monisha Kesherwani; T.D. Singh; V.P. Singh; V.B. Pandey; U.P. Singh
The isomeric alkaloids jatrorrhizine and columbamine isolated from the whole plant of Argemone mexicana were assessed against spore germination of some fungi, e.g. Alternaria cajani, Bipolaris sp., Helminthosporium sp., Fusarium udum and Curvularia sp. Both the alkaloids were effective against most of the fungi tested. Jatrorrhizine was highly effective against spore germination of Bipolaris sp., Fusarium udum and Curvularia sp. at 5000 ppm concentration, whereas columbamine was highly effective against Alternaria cajani, Helminthosporium sp. and Fusarium udum at 5000 ppm. © 2010 Taylor & Francis.
Metabolite profiling can assist variabilityy analysis in Trichoderma species
(Taylor and Francis Ltd., 2011) Amitabh Singh; Birinchi K. Sarma; Udai P. Singh; Rajesh Singh; Harikesh B. Singh; Krishna P. Singh
Variability in 41 isolates of Trichoderma belonging to 21 species was observed in the phenolic acid profile of their culture filtrates. The phenolic acid profiles were observed to be very stable in the culture filtrate of Trichoderma species. The similarity in phenolic acid profile was recorded and based on it the species were grouped into three distinct groups, viz. highly similar, moderately similar and least similar. Of the 21 species, seven species showed highly similar trend, whereas two and four species showed moderate and least similarity in their phenolic acid profiles, respectively. Looking into the stability of phenolic acid profile in the culture filtrate of the Trichoderma species the present tool may help in diversity analysis in Trichoderma species originating from different geographical areas. © 2011 Taylor & Francis.
Phenolic acid changes in mycelia of Sclerotium rolfsii as influenced by neem (Azadirachta indica) cake and Zephyarenthes citrina bulb
(2010) U.P. Singh; Leena Gohain; Amitabh Singh; S. Maurya; S. Sahni
High performance liquid chromatographic (HPLC) analysis of mycelia of Sclerotium rolfsii grown on neem cake, and Zephyarenthes citrina bulb incorporated media was carried out. Several phenoloic acids, e.g., gallic, tannic, caffeic, cinnamic, chlorogenic and O-coumeric acids, were found in considerable amounts in treated mycelial mat as compared to the control. The amount of phenloic acids increased with increased concentration of both the materials in mycelia of 7 and 14 day-old cultures. Due to anti-oxidant and several other properties of phenolic acids, the senescence of the fungus has been prolonged which may be one probable reason of sustaining the virulence of the pathogen. © 2010 Taylor & Francis.
Phenolic acids in some Indian cultivars of Momordica charantia and their therapeutic properties
(2011) Udai Pratap Singh; Sudarshan Maurya; Amitabh Singh; Mandavi Singh
Bitter gourd (Momordica charantia) is an important medicinal plant consumed mostly as vegetable. Often the whole plant is used in different forms for improving human health. Phenolic acid analysis by high performance liquid chromatograph (HPLC) of three cultivars of M. charantia (viz., Pusa Vishesh, Kalyanpur Barasati and Priya) has been done. Kalyanpur Barasati was rich in some phenolic acids (six phenolic acids) followed by Pusa Vishesh and Priya (five phenolic acids). Gallic, caffeic, chlorogenic and ferulic acids were detected in fruit parts of all the three varieties where gallic acid was in maximum amount. Caffeic acid was maximum in Pusa Vishesh and Kalyanpur Barasati. In roots and leaves, phenolic acids were detected in traces. The importance of fruits which are consumed as vegetable in human diet has been discussed in the light of phenolic acid content. © 2011 Academic Journals.
Role of air and light in sclerotial development and basidiospore formation in Sclerotium rolfsii
(2010) Sudarshan Maurya; Udai Singh; Rashmi Singh; Amitabh Singh; Harikesh Singh
Sclerotium rolfsii is one of the devastating soil-borne phytopathogens which causes severe loss at the time of seedling development. It also causes leaf spots in several crops and wild plants. Petri plates, containing potato dextrose agar medium, were inoculated with S. rolfsii. Two-third area of three, 50% area of three and 100% area of other three plates were sealed with cellophane tape. The other three plates were not sealed. All the plates were incubated at 27±2°C. Two sets of such plates were prepared. One set was incubated in light whereas the other set in the dark. There was no significant difference in mycelial growth and number of sclerotia among them but significant difference was observed when compared to the control, i.e. the plates which were not sealed. Sclerotium and basidiospore formation were directly influenced by air as completely sealed plates failed to produce sclerotia and basidiospores. Basidiospores were produced abundantly in the light and in the dark conditions in unsealed plates only on Cyperus rotundus rhizome meal agar medium.
The mixture of tertiary and quaternary alkaloids isolated from argemone ochroleuca inhibits spore germination of some fungi
(2010) Sarita Singh; Amitabh Singh; Monisha Keshariwala; T.D. Singh; V.P. Singh; V.B. Pandey; U.P. Singh
The mixture of tertiary and quaternary alkaloids isolated from Argemone ochroleuca was separately assessed against spore germination of some plant pathogenic fungi, e.g. Alternaria alternata, Alternaria brassicae, Alternaria cajani, Bipolaris sp., Curvularia lunata, Curvularia sp., Colletotrichum musae, Fusarium udum, Helminthosporium sp., Helminthosporium pennisetti and Helminthosporium speciferum. Spore germination of Fusarium udum and Helminthosporium sp. was completely inhibited at very low concentration (200 ppm). A similar effect was observed on A. alternata, C. musae and H. pennisetti at 600, 800 and 1000 ppm. With quaternary alkaloids, Curvularia sp. And Colletotrichum musae were most sensitive as complete inhibition of spore germination was observed at 400, 600, 800 and 1000 ppm and a similar effect was observed with A. brassicae and A. cajani at 600, 800 and 1000 ppm. The remaining fungi were also highly sensitive to the mixture at different concentrations. © 2010 Taylor & Francis.
Therapeutic importance and analysis of phenolic acids in different parts of Syzygium cumini Linn
(IOS Press BV, 2013) Udai Pratap Singh; Sudarshan Maurya; Shraddha Nayak; Mandavi Singh; Amitabh Singh
Jamun (Syzygium cumini), which belongs to the family Myrtaceae, is an important indigenous minor fruit of commercial value. S. cumini fruit possesses considerable nutritive value because it is a rich source of carbohydrates, proteins, iron, calcium, minerals, vitamins as well as phenolic acids. Leaves are rich in phenolic acids in which tannic acid was maximum followed by caffeic acid. Tannic acid is also maximum in ripe fruit epicarp, seeds and mesocarp as compared to unripe fruit epicarp. Caffeic and cinnamic acids are also present in ripe fruit seeds. Other phenolic acids are present in traces. Tannic acid was maximum in the seeds of unripe fruits followed by chlorogenic and gallic acids and some other phenolic acids. The therapeutic properties of these phenolic acids are discussed. © 2013 Springer-Verlag Italia.