Browsing by Author "J.S. Srivastava"

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Antifungal activity of bergenin, a constituent of Flueggea microcarpa
(Blackwell Publishing Ltd, 1997) B. Prithiviraj; U.P. Singh; M. Manickam; J.S. Srivastava; A.B. Ray
The antifungal activity of bergenin against some plant pathogenic fungi, namely, Alternaria alternata, A. brassicae, A. carthami. Fusarium udum, F. oxysporum f. sp. ciceri, Curvularia lunata and Erysiphe pisi, was studied. Bergenin as its monosodium salt was effective against all the fungi and the effective dose for complete inhibition of spore germination varied from 15 μg mL-1 for F. udum to 125 μg mL-1 for E. pisi. Experiments on the effect of bergenin on powdery mildew development under glasshouse conditions revealed that it can control powdery mildew of pea at 2000 μg mL-1 by postinoculation treatment, the results being comparable with those of carbendazim (1000μg mL-1) and wettable sulfur (2000 μg mL-1). It affected hyphal elongation and the number of primary and secondary branches.
Antifungal activity of Δ3-alstovenine, a plant alkaloid isolated from Alstonia venenata
(Czech Academy of Sciences, 1999) S.K. Singh; B.K. Sarma; J.S. Srivastava; U.P. Singh; A.B. Ray
A plant quaternary alkaloid Δ3-alstovenine inhibited the spore germination of most of the fungi tested at concentration of 250-1000 mg/L. Saprophytic and biotrophic fungi were equally sensitive to the alkaloid. Cercospora sp. was the most sensitive as 100% inhibition of spore germination was observed at 250 mg/L. Alternaria species, Curvularia species and Fusarium udum were not affected even at 1000 mg/L.
Arbuscular mycorrhizal fungi induced biochemical changes in pea (Pisum sativum) and their effect on powdery mildew (Erysiphe pisi)
(2004) D.P. Singh; J.S. Srivastava; Amar Bahadur; U.P. Singh; S.K. Singh
Colonization of Glomus mosseae and Pseudomonas fluorescens (mutant Pf2) increased the growth of three pea (Pisum sativum) cultivars such as 'Rachna', 'HUDP16' and 'HUP2'. When colonized with mutant Pf2, all the three cultivars exhibited maximum biomass accumulation in terms of shoot and root weight. Treatment with Pf2 mutant also resulted in greater nodulation, e. g., 31, 33 and 34 nodules/ plant in 'Rachna', 'HUDP16', 'HUP2', respectively, as compared to mycorrhizal and control plants. Plants colonized with G. mosseae gave greater yield. Various levels of qualitative as well as quantitative accumulation of phenolic acids were observed in pea plants in response to the colonization with G. mosseae and mutant Pf2. Qualitatively, certain phenolic acids, namely, tannic, gallic, vanillic and ferulic acids, were identified with more prominent quantitative variations. Plants of all the cultivars showed greater accumulation of phenolic acids in treatments than the control. In all the cultivars, mycorrhizal colonization occurred irrespective of whether the plants were infected with Erysiphe pisi. About 70 % colonization of G. mosseae was observed in the above pea cultivars. In plants infected by E. pisi, maximum content of total phenolics was recorded in 'HUP2' followed by 'Rachna' and 'HUDP16'. Mycorrhizal colonization and total phenolic accumulation were closely correlated with disease intensity (D. I.) on pea plants. Control plants of 'Rachna' showed maximum D. I. (55.2 %) followed by 'HUP2' and 'HUDP16', whereas mycorrhizal plants of 'HUDP16' showed minimum D. I. (28.7 %) as compared to 'HUP2' and 'Rachna'.
Biological management of common scab of potato through Pseudomonas species and vermicompost
(2011) P.K. Singhai; B.K. Sarma; J.S. Srivastava
Four Pseudomonad strains were used with or without vermicompost amendment to see their performance on potato plant growth and yield along with suppression of common scab of potato. Two locations in the Varanasi district of India were selected as they had been under potato cultivation for the past one decade and the scab pathogen was well established. Among the various treatments, the Pseudomonad strain R1 when applied with vermicompost gave the best plant growth and yield along with maximum reduction in scab incidence and scab index. The strain R1 was later identified as Pseudomonas mosselii. The treatment also showed maximum activities of the antioxidant enzyme peroxidase (POX) and the first enzyme of the phenylpropanoid pathway phenylalanine ammonia lyase (PAL) in a pot experiment till 72. h after pathogen challenge and then declined thereafter. Interestingly the activities of both POX and PAL were higher in the potato tuber peels, the active site of pathogen interaction, than in the potato leaves. The results revealed the potential of P. mosselii strain R1 in promoting plant growth as well as inducing antimicrobial mechanisms systemically in the host plants facilitated by the organic amendment in the form of vermicompost. © 2011 Elsevier Inc.
Characterization of phenolic compounds in some Indian mango cultivars
(2004) U.P. Singh; D.P. Singh; Mandavi Singh; S. Maurya; J.S. Srivastava; R.B. Singh; S.P. Singh
Mangoes (Mangifera indica) are rich in phenolic acids as detected by high-performance liquid chromatography. The phenolics have prominent medicinal properties. Among six important commercial mango cultivars (Deshi, Langra, Chausa, Mallika, Dashahari and Amrapali) tannic acid was maximal in Mallika, while gallic acid was maximal in Chausa and all other varieties. Caffeic acid was maximal in Langra followed by Chausa and Amrapali. Many of the pharmacological properties attributed to mango might be due to the presence of phenolic acids in fairly significant amounts. © 2004 Taylor & Francis Ltd.
Differential expression of pea symbiotic plasmid pJB5JI in genetically dissimilar backgrounds
(1990) J.S. Srivastava; J.E. Beringer
[No abstract available]
Effect of azide on cowpea Rhizobium strain 32HI
(1981) J.S. Srivastava; B.D. Singh; V.P. Tewari
[No abstract available]
Effect of Ca2+, Mg2+, light, temperature and pH on athelial stage formation in Sclerotium rolfsii Sacc.
(2000) B. Prithiviraj; B.K. Sarma; J.S. Srivastava; U.P. Singh
The role of the divalent cations, Ca2+ and Mg2+ as well as light, temperature and pH in the induction of sexual reproduction of Sclerotium rolfsii in potato dextrose agar medium supplemented with Cyperus rotundus rhizome powder was investigated. EDTA (ethylenediaminetetraacetic acid) at 15 mmol/l suppressed hymenium induction without affecting growth or sclerotium formation. This effect was reverted by the addition of divalent cations. Chlorpromazin, a calmodulin antagonist, and ruthenium red, an organelle Ca2+ channel blocker, did not have any effect on the induction process. Continuous white light inhibited the sexual stage formation while blue, green and red light did not. Maximum percent area covered in the Petri dish by basidial stage was produced under complete darkness at a range of pH 4-8.
Effect of Mannich Bases on Some Plant Pathogenic Fungi
(Czech Academy of Sciences, 1998) B.K. Sarma; J.S. Srivastava; B. Prithiviraj; U.P. Singh; S.N. Pandeya
3-(2-Pyridyl)-3-iminoisatin, 1-piperidinomethyl-3-(2-pyridyl)-3-iminoisatin, and 1-acetyl-3-(2-pyridyl)-3-iminoisatin affect spore germination of Alternaria alternata, A. carthemi, Curvularia lunata, Fusarium oxysporum f.sp. ciceri and F. udum and influence the development of powdery mildew (Erysiphe pisi) on pea under glasshouse condition as well as conidial germination of E. pisi on excised pea leaves. Spore germination was inhibited in the sequence 1-acetyl-3-(2-pyridyl)-3-iminoisatin > 1-piperidinomethyl-3-(2-pyridyl)-3-iminoisatin > 3-(2-pyridyl)-3-iminoisatin followed the order accordingly. The powdery mildew development and conidial germination of E. pisi 1-piperidinomethyl-3-(2-pyridyl)-3-iminoisatin > 1-acetyl-3-(2-pyridyl)-3-iminoisatin > 3-(2-pyridyl)-3-iminoisatin. The chemicals were compared with commonly used antifungal fungicides.
Efficacy of alkaloid (-)-corypalmine against spore germination of some fungi
(Czech Academy of Sciences, 2002) S. Maurya; J.S. Srivastava; R.N. Jha; V.B. Pandey; U.P. Singh
Inhibition activity of the alkaloid (-)-corypalmine on spore germination of plant pathogenic and saprophytic fungi (Alternaria solani, A brassicicola, A. brassicae, A. melongenae, Curvularia pallescens, C. lunata, C. maculans, Curvularia sp., Colletotrichum sp., Helminthosporium speciferum, H. frumentacei, H. pennisetti, Heterosporium sp., Penicillum sp., Ustilago cynodontis) was determined. Spore germination of all the tested fungi was inhibited, Heterosporium sp. and Ustilago cynodontis being the most sensitive (complete inhibition of spore germination was observed at the very low concentration of 200 ppm). Curvularia palliscens, C. maculans and Curvularia sp. were less sensitive; complete inhibition of spore germination occurred at 400 ppm.
Evaluation of biocontrol potential of Arthrobotrys oligospora against Meloidogyne graminicola and Rhizoctonia solani in Rice (Oryza sativa L.)
(2012) Udai B. Singh; Asha Sahu; R.K. Singh; Dhananjaya P. Singh; Kamlesh K. Meena; J.S. Srivastava; Renu; M.C. Manna
The nematode trapping and mycoparasitic potential of Arthrobotrys oligospora was tested in vitro against Meloidogyne graminicola and Rhizoctonia solani, respectively. Five isolates of A. oligospora were isolated from different locations of India. Diversity of the trapping structures is large and highly dependent on the environmental condition and nature of the fungus. In A. oligospora, a three-dimensional adhesive net (in response to nematode) and hyphal coils developed around the hyphae of R. solani. In vitro trap formation and predacity were tested against second-stage juveniles of M. graminicola (J 2) and the interactions between A. oligospora and R. solani were recorded. Under field conditions, we demonstrated the biocontrol potential of A. oligospora against R. solani causing sheath blight of rice (Oryza sativa) for the first time. All the isolates of A. oligospora parasitized and killed M. graminicola and R. solani. Application of A. oligospora, isolate VNS-1, in soil infested with M. graminicola and R. solani reduced the number of root knot by 57.58-62.02%, sheath blight incidence by 55.68-59.32% and lesion length by 54.91-66.66% under green house and miniplot (field) conditions. Applications of A. oligospora to the soil increased plant growth: shoot length by 56.4-68.8%, root length by 44.0-54.55%, fresh weight of shoot and root by 62.91-65.4% and 38.9-44.19%, respectively, as compared to the plants grown in nematode infested soil. © 2011 Elsevier Inc.
Individual and combined effects of berberine and santonin on spore germination of some fungi
(Czech Academy of Sciences, 2001) B. Singh; J.S. Srivastava; R.L. Khosa; U.P. Singh
Berberine and santonin were isolated from rhizomes of Berberis aristata and unexpanded flower buds of Artemisia maritima, respectively. Efficacy of these two chemicals individually as well as of their mixtures, was tested against spore germination of some saprophytic and obligate fungi. While berberine individually was effective against most of the fungi, Helminthosporium spp. were least affected even at the highest dose (1500 ppm). Santonin was equally effective against several fungi. Mixture of both alkaloids found to be more effective than individual ones. Keeping the dose of berberine constant and santonin at two different concentrations (viz. 250 and 500 ppm) the spore germination of Helminthosporium oryzae was stimulated. Increasing concentration of santonin inhibited the spore germination of all other fungi tested, Colletotrichum capsici being affected only by 20 and 5 % (at berberine concentration of 250 and 500 ppm, respectively). On the other hand, santonin being constant and berberine at different concentrations, the mixture was effective against all the fungi.
Isolation and characterization of a virus (RL 1) infective on Rhizobium leguminosarum
(Springer-Verlag, 1978) B. Dhar; B.D. Singh; R.B. Singh; R.M. Singh; V.P. Singh; J.S. Srivastava
A virus (RL 1) that infects Rhizobium leguminosarum was isolated and studied. The virus has phagelike morphology; it has a hexagonal head and a long, flexible, noncontractile tail with a baseplate. The edgeto-edge diameter of head is 760 Å. The tail is 1515 Å long and 115 Å wide. RL 1 is stable at 4° C in distilled water, with only 20% loss in the titer after one month storage. It does not require any ion for stability, and is stable between pH 6.0 and 8.0. The virus is composed of two components; one is thermal sensitive and the other is relatively thermal resistant. Adsorption and 'one step growth' experiments under normal growth conditions showed a slow adsorption rate (0.82×10-9 cm3 min-1) followed by a 90 min latent period. The burst size was approximately 100 virus particles per cell. © 1978 Springer-Verlag.
Management of Collar Rot of Chickpea (Cicer Arietinum) by Trichoderma Harzianum and Plant Growth Promoting Rhizobacteria
(2008) S. Maurya; Rashmi Singh; D.P. Singh; H.B. Singh; U.P. Singh; J.S. Srivastava
Collar rot (Sclerotium rolfsii) of chickpea (Cicer arietinum) is one of the devastating soil-borne diseases of fungal origin, due to which 10-30% yield loss is recorded annually according to severity of the disease. Management of collar rot of chickpea is not feasible in the absence of effective soil fungicides. However, Trichoderma harzianum and plant growth promoting rhizobacteria (PGPR) have shown high efficacy against this disease in vitro as well as in the field. We used T. harzianum (104, 106 and 10-8 spore/ml) and two PGPRs (Pseudomonas fluorescens strain 4 and P. aeruginosa) as foliar spray with the fresh and heat inactivated microorganisms. Foliar application of T. harzianum (10-8. spore/ml) and P. fluorescens strain 4 (108 cfu/ml) showed maximum efficacy in reducing plant mortality as compared to the control. Foliar application of fresh-and heat-inactivated (121°C for 10 min) P. fluorescens strain 4, and T. harzianum reduced 15-25% plant mortality but P. aeruginosa showed very little disease control of 10-15%. However, regarding plant growth promotion, it was observed that fresh-and heatinactivated P. fluorescens strain 4 showed maximum efficacy followed by fresh and heat inactivated P. aeruginosa and T. harzianum as compared to the control. The disease-controlling efficacy was also associated with the increase in phenolic acid synthesis in chickpea plants. The control of chickpea collar rot by biocontrol agents is safe and ecologically sound and appears to be a healthy approach to the disease control. © 2008, Versita. All rights reserved.
Molecular and biochemical aspects of rhizobacterial ecology with emphasis on biological control
(1999) Veena Kumari; J.S. Srivastava
The rhizosphere is the narrow zone of soil surrounding the root that is subject to influence by the root. Rhizobacteria are plant-associated bacteria that are able to colonize and persist on roots. An understanding of the ecology of a microorganism is a fundamental requirement for the introduction of a microbial inoculant into the open environment. This is particularly true for biological control of root pathogens in the rhizosphere, where one is actively seeking to alter the ecological balance so as to favour growth of the host plant and to curtail the development of pathogens. Some strains of plant growth-promoting rhizobacteria can effectively colonize plant roots and protect plants from diseases caused by a variety of root pathogens and growth promotion of plants through direct stimulation of growth hormone. Such beneficial or plant health-promoting strains are emerging as promising biocontrol agents. They are suitable as soil inoculants either individually or in combination and may be compatible with current chemical pesticides. Considerable progress has been achieved using molecular genetic techniques to elucidate the important microbial factors or genetic traits involved in the suppression of fungal root diseases. Strategies utilizing molecular genetic techniques have been developed to complement the ongoing research ranging from the characterization and genetic improvement of a selected biocontrol agent to the measurement of its persistence and dispersal. Finally, biocontrol is considered as part of a disease control strategy like integrated pest management which offers a successful approach for the deployment of both agro-chemicals and biocontrol agents.
Nematophagous fungi: Catenaria anguillulae and Dactylaria brochopaga from seed galls as potential biocontrol agents of Anguina tritici and Meloidogyne graminicola in wheat (Triticum aestivum L.)
(2013) Udai B. Singh; Asha Sahu; Nisha Sahu; R.K. Singh; Renu; Dinesh K. Singh; Bhanu P. Singh; R.K. Jaiswal; Dhananjaya P. Singh; J.P. Rai; M.C. Manna; K.P. Singh; J.S. Srivastava; A. Subba Rao; S. Rajendra Prasad
During the course of our investigation on the selective isolation and in vitro pathogenicity tests of the nematode egg parasite and endoparasitic Catenaria anguillulae and the nematode-trapping fungus Dactylaria brochopaga against Anguina tritici, and Meloidogyne graminicola, the two biocontrol agents were also examined for their capabilities to colonize wheat seed gall and also to reduce the M. graminicola, and A. tritici in wheat (Triticum aestivum L.). Using seed galls as bait was found effective for isolating the soilborne natural colonizers of seed galls of wheat caused by A. tritici. Seed galls were found severely infested with cellulose decomposers as well as nematode trapping fungi i.e., Fusarium spp. ., Verticillium spp., Aspergillus spp., Penicillium spp. Arthrobotrys oligospora, Arthrobotrys superba, Arthrobotrys dactyloides, Arthrobotrys musiformis, D. brochopaga, Monacrosporium eudermatum, Stylopaga hadra, Paecilomyces spp., and C. anguillulae. Co-inoculation of D. brochopaga DBS-105, and C. anguillulae CAS101 significantly reduced the root knot and seed gall in wheat and increased the plant growth parameters including length, and dry weight of root and shoot as well as yield attributing characters like spike length; number of seed per spike, test weight etc. under greenhouse conditions as compared to pathogen challenged plants without any bioagents/chemical nematicide. These bioagents have the potential to enhance production of quality seeds of wheat being free from hazardous pesticides and thus, can further be developed into marketable formulations in order to promote eco-friendly and sustainable means of crop production. © 2013 Elsevier Inc.
Phenolic compounds of Sorghum vulgare in response to Sclerotium rolfsii infection
(2007) S. Maurya; Rashmi Singh; D.P. Singh; H.B. Singh; J.S. Srivastava; U.P. Singh
Identification of individual phenolic acids of Sorghum vulgare Pers. cv. M.P. after interaction with Sclerotium rolfsii Sacc. using high performance liquid chromatograph (HPLC) showed the presence of phenolics namely tannic, gallic, ferulic, chlorogenic and cinnamic acids in varying amounts. After 72 h inoculation with S. rolfsii, a maximum amount of ferulic acid (166.6 μg g-1 fresh wt) was present in the collar of inoculated plants, followed by leaves and roots and its level decreased gradually with time. Similarly, the presence of chlorogenic acid was traced after 48 h, while that of cinnamic acid was traced after 72 h of inoculation. Reddish-brown pigmentation at the collar region of inoculated plants was also observed along with the high content of tannic acid. Among other phenolics, the presence of gallic acid was recorded consistently and maximum accumulation (139.3 μg g-1 fresh wt) was noticed at the zone of interaction (collar region) after 72 h of inoculation. In contrast, maximum lignin deposition was observed at collar region after 96 h of inoculation. Induction of phenolic acids in S. vulgare along with the lignin deposition and red pigmentation at collar region is considered a key biomarker in the non-host-pathogen interaction in the S. valgare-S. rolfsii pathosystem. © 2007 Taylor & Francis.
Plant growth promotion and management of collar rot of Chickpea (Cicer arietinum) by mycelial protein of Sclerotium rolfsii
(2009) S. Maurya; D.P. Singh; U.P. Singh; J.S. Srivastava
Investigations on the total protein content of seven isolates of Sclerotium rolfsii and the effect of the total protein of different isolates on growth promotion and management of collar rot disease of chickpea was carried out. Various concentrations (0.07, 0.14, 0.21 and 0.28mg/ml in terms of BSA fraction V equivalents) of fungal protein isolated from BHU-3 isolate, which contained maximum total protein, was sprayed on 20-day-old chickpea (Cicer arietinum) plants. After four days, the sprayed potted plants were inoculated with S. rolfsii and observations were taken on the growth, mortality and phenolic acid content of plants. Among different concentrations of fungal protein, 0.21 and 0.28mg/ml showed maximum efficacy in plant growth promotion. Also, plant mortality was reduced significantly compared to control following treatment of fungal protein. Phenolic acid content of plant leaves after spray of fungal protein increased compared to control. Further, the level of phenolic acids in plants inoculated with S. rolfsii increased, indicating an important role of the fungal protein in inducing resistance in plants. The results suggest a functional role of fungal protein of the isolate BHU-3 in plant growth promotion as well as resistance induction analogous to phytoimmunoproteins responsible for induction of immune response in plants.
Screening potato cultivars for common scab of potato in a naturally infested field
(European Association for Potato Research, 2001) K.K. Mishra; J.S. Srivastava
Twenty seven cultivars of potato were screened for common scab grown in a commercial field in two successive years (1996-97 and 1997-98). Eight cultivars were least susceptible and the others ranged from medium susceptible to very highly susceptible. None of the cultivars was resistant. Most showed a stable resistance reaction in both years.
Secondary metabolites of chickpea (Cicer arietinum) and their role in pathogenesis after infection by Sclerotium rolfsii
(2005) S. Maurya; U.P. Singh; D.P. Singh; K.P. Singh; J.S. Srivastava
HPLC analysis of various parts of chickpea (Cicer arietinum) 24, 48, 72 and 96 h after infection with Sclerotium rolfsii indicates that the plants contain high amount of secondary metabolites. Analysis of 24 h-colonized rot collar region, plant leaves and roots of chickpea showed that gallic, o-coumaric and salicylic acids were maximum in these parts as compared to control (uninoculated) plant parts. In the collar region after 48 h, gallic acid was maximum followed by tannic, chlorogenic, salicylic and o-coumaric acids but vanillic and cinnamic acids were in traces. The un-inoculated collar region contained only five phenolic acids. After 72 h of colonization, the level of phenolic acids was drastically changed in collar, leaves and roots. Gallic acid was maximum followed by vanillic and other phenolic acids as compared to un-inoculated leaves. However, in collar the number and amount of phenolic acids was drastically reduced with increased amount of gallic and tannic acids. The chlorogenic and salicylic acids were in traces as compared to the control. Roots of inoculated and un-inoculated plants had four phenolic acids. In 96 h-colonized chickpea plants, leaves had only four phenolic acids in which gallic acid was maximum followed by vanillic, coumaric and salicylic acids. In the un-inoculated plant leaves, six phenolic acids were present in which gallic acid was maximum followed by vanillic, tannic, chlorogenic, salicylic and coumaric acids. In colonized and un-inoculated collar regions, gallic and tannic acids were maximum but others in traces. The un-inoculated roots were rich in phenolic acids as compared to inoculated. © Eugen Ulmer GmbH & Co.