NBU Journal of Plant Sciences
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The NBU Journal of Plant Sciences serves as the official organ of the Department of Botany for the publication of research papers by its members and researchers. The journal is sent free to its members and different academic institutions on demand.
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Item Open Access Can household-level fermentation technology assure food safety?(University of North Bengal, 2007-03) Sarkar, Prabir KThe term 'fermented food" is defined as any food that has been subjected to the action of microorganisms or enzymes so that desirable biochemical changes cause significant modification of the food. Fermented foods enjoy worldwide popularity as attractive, wholesome and nutritious components of our diet. In the past, household-level fermentation technology originated and evolved through trial and error experiences gathered by successive generations of food producers. Only relatively recently have science and technology started to a better understanding of the underlying principles of the fermentation processes and of the essential requirements to ensure nutritional and sensory qualities as well as safety of fermented foods.Item Open Access Immunotechniques: Concept and application in plant pathology(University of North Bengal, 2007-03) Saha, A.; Dasgupta, S.; Saha, D.Proper management of plant diseases requires accurate disease diagnosis and precise identification of the phytopathogens involved. Traditional and conventional methods of disease diagnosis and pathogen detection have several demerits. It takes a lot of time to diagnose a disease and to identify a pathogen accurately by traditional approaches. Moreover, results are not always conclusive because similar symptoms can be caused by different pathogens or physiological conditions and sometimes it is very difficult to distinguish closely related organisms on the basis of their morphological characters only. Thus the traditional methods normally applied for pathogen identification and disease diagnosis are less sensitive and less reliable. The need for rapid and accurate identification and diagnostic methods to identify the organisms that cause plant diseases are essential for the formulation of effective disease control strategies.Item Open Access Tea Polyphenols: variation with respect to agro-climatic condition, their impact in human health and soil environment(University of North Bengal, 2007-03) Misra, Tarun Kumar; Mandal, PalashTea is the richest source of different kinds of polyphenols and potential antioxidants. recent years numerous biochemical and physiological studies have demonstrated that accumulation of polyphenols in tea is significantly related to soil nutrient availability. In this review recent advances in current understanding of bioactive polyphenols and their accumulation in tea plant have been discussed concisely.Item Open Access Ethnobotanical studies in India with notes on Terai-Duars and Hills of Darjiling and Sikkim(University of North Bengal, 2007-03) Das, A. P.; Ghosh, Chandra; Sarkar, Ajita; Biswas, RajibThe very survivability of man is greatly associated with plants since his origin. Plants are responsible for the supply of Man's oxygen, food, medicine, fibre, shelter and what not! Also the relationship between man and environment in general has never been static and is changing continuously. But this is not the case with tribal/ aboriginal communities the world over. The life, culture and traditions of these communities have remained almost undisturbed and static for hundreds of years. They are the living archaeological museums of ancient traditions and cultural heritage of a nation.Item Open Access Reactive oxygen species and environmental stresses(University of North Bengal, 2007-03) Chakraborty, UshaReactive oxygen species (ROS) include oxygen ions, free radicals and peroxides both inorganic and organic. They are generally very small molecules and are highly reactive due to the presence of unpaired valence shell electrons. ROSs form as a natural byproduct of the normal metabolism of oxygen and have important roles in cell signaling. While ROS have the potential to cause oxidative damage to cells during environmental stress, recent studies have shown that ROS play a key role in plants as signal transduction molecules involved in mediating responses to pathogen infection, environmental stresses, programmed cell death and developmental stimuli. The rapid increase in ROS production, referred to as 'the oxidative burst', was shown to be essential for many of these processes, and genetic studies have shown that respiratory burst oxidase homolog (Rboh) genes, encoding NADPH oxidases, are the main producers of signal transduction-associated ROS in cells during these processes.Item Open Access Agrobacterium-mediated gene transfer in higher plants(University of North Bengal, 2007-03) Roy, Subhas ChandraThe genetic engineering of plants actually started with the discovery of a pathogenic bacterium, Agrobacterium tumefaciens, causing a disease known as crown gall (tumor). The bacterium transfers a set of genes from its plasmid into infected plant cells, where the transferred genes are expressed and produced gall at the junction of root and stem (i.e., crown region of the plant). This discovery has revolutionized the plant transformation method through which any gene can be introduced into plant genome to change their genetic make-up for commercial benefits, spaning from disease resistance to the production of pharmaceutically important proteins.Item Open Access Anthrax and Bioterrorism(University of North Bengal, 2008-03) Chowdhury, J.; Sen, A.Bioterrorism is the deliberate discharge or dissemination of viruses, bacteria, or other germs used to cause sickness or death in people, animals, or plants. Though these agents are found in nature they are usually modified to increase their ability to cause disease, make them resistant to current antibiotics, or to increase their ability to be spread into the environment. Biological agents can be spread through the air, through water, or in food. Terrorists may use biological agents because they can be extremely difficult to detect and do not cause illness for several hours to several days. Among these biological agents, Anthrax is considered to be the Category-A agent because of its high potency for adverse public health impact and serious effect on large-scale dissemination. Though there is a big hue and cry in the recent past about bioterrorism particularly after 9/11 attack, the history of bioterrorism is fairly old. In the present paper, we have sketched the history and the evolution of bioterrorism with reference to anthrax, particularly microbiology and pathogenesis of the disease causing agent and its clinical symptoms and treatments.Item Open Access Ethnic uses of some pteridophytic weeds of tea gardens in Darjeeling and Terai(University of North Bengal, 2008-03) Ghosh, C.; Biswas, R.; Das, A.P.Pteridophytes occupy a recognisable position in the flora of Terai and the hills of Darjiling. They are also well represented as weed in the Tea Gardens of this area. Recent survey recorded the occurrence of 86 species of pteridophytes from nine such gardens covering both Terai and Darjiling Hills. Of these, 25 species (30%), covering 21 genera and 20 families, are used by the Tea Garden workers in different manner like (i) 10 species as food, (ii) 02 species for fermenting traditional liquor, (iii) 01 species as fodder and (iv) 22 species as medicine for human diseases. In addition, some of these plants are used for basketry, playing carom, ceremonial decoration, ornamentals etc.Item Open Access Diversity ofTrees in the Darjeeling Foothill Region of Eastern Himalaya(University of North Bengal, 2008-03) Rai, U.; Das, A. P.Phytosociological investigation using 20 x 20 m quadrats has been made on seven major forest types of Darjiling foothill region within an altitudinal range of 135 m to 1200 m leading to the record of 215 species of trees, 11 species of liana and three species of palms. Analysis of data revealed that the East Himalayan Sal forest showed highest species diversity but have moderate species richness and concentration of dominance. High species diversity and species richness were recorded from Semi Evergreen Mixed forest, Wet Mixed Deciduous Forest & Lower Bhabar Sal Forest with correspondingly low concentration of dominance. Bamboo brake had the lowest species diversity with high concentration of dominance. Computation of similarity index showed a poor relation between different forest types and reflected the developing nature of vegetation. Also, these forests have a high regeneration status with a good species composition. It has also been predicted that the anthropogenic interferences may cause the abrupt change in the structure of these vegetation types.Item Open Access Plant Defense Proteins(University of North Bengal, 2008-03) Chakraborty, B.N.Plants are compelled to withstand stresses of all kinds, be it biotic, abiotic or anthropogenic as a consequence of their immobility. The initial infection process involving adhesion/recognition events between plants and fungal pathogens is essential for the establishment of pathogenesis. The extracellular matrix (ECM) is a biologically active part of the cell surface composed of a complex mixture of macromolecules that, in addition to serving a structural function, profoundly affect the cellular physiology of the organism. During the past two decades it has become evident that the cell wall is a dynamic organization that is essential for cell division, enlargement and differentiation as well as responding to biotic and abiotic stress. ECM is also the source of signals for cell recognition within the same or between different organisms. Cell walls are natural composite structures, mostly made up of high molecular weight polysaccharides, proteins and lignins. Lignins are only found in specific cell types. Arabidopsis thaliana cell wall proteins (CWP) that can be involved in modifications of cell wall components, wall structure and signaling as well as interactions with plasma membrane proteins at the cell surface has been reviewed.Item Open Access Antagonism of fluorescent Pseudomonas BRL-1 against Curvularia lunata(University of North Bengal, 2008-03) Sen, S.; Tahsin, K.S.; Acharya, K.A potato rhiszospheric isolate, fluorescent Pseudomonas BRL-I, showed in vitro antagonistic activity against Curvularia lunata. Microscopic studies of the mycelium after antagonism illustrated hyphal shriveling, swelling, vaculation, short branching and granulation of cytoplasm resulting in lysis of hyphae of C. lunata.. Association of antagonistic property of the isolate has been found to be coupled with chitinolytic and proteolytic activity as weii as by the production of indole acetic acid and spiderophore.Item Open Access Variation of antioxidant properties and phytochemical constituents of tea cultivated under various agronomic conditions at Terai region of North Bengal(University of North Bengal, 2008-03) Misra, T.K.; Saha, A.; Nanda, A.K.; Mandal, P.The studies were conducted during 2007-2008 in three cultivars of tea (Camellia sinensis) namely, TV26, TV29 and Dangri Manipuri Jat, at tea estates of Terai, North Bengal. Commercial standard plucked tea leaves were assayed to determine antioxidants activity and related phytochemical constituents. DPPH was used to determine the antioxidant properties of bud+leaf (B+L), bud+two leaves (B+2L), bud+three leaves (B+3L) and matured leaves (L). Subsequently, total phenolics, flavonols and hydrolysable tannins were estimated using standard methods. The result showed that free-radicals scavenging potentiality and chemical composition varies significantly at different growing conditions and leaf maturation. Statistical analysis showed significant relation between antioxidant and some phytochemical composition of dry tea leaves, among which phenolics (R2 =0.904, P< 0.001), tannins (R2= 0.567, P< 0.05) and flavonols (R2= 0.314, P< 0.05) bear significant correlation. Soil physicochemical parameters like pH (R2=0.537, P< 0.05), nitrogen (R2=0.618, P< 0.01), K2O (R2=0.106, insignificant), P2O5 (R=0.730, P< 0.01), S (R2=0.157, insignificant) and soil moisture (R2=0.745, P< 0.01) influence free-radical scavenging activity in tea leaves. Antioxidant quality of tea varies with maturation stages of leaves and the pattern is specific for a selected varietes. From our observation it may be concluded that antioxidant quality is dependent on some fertility parameters of soil and maturation of leaf. These results suggests that appropriate agronomic practices and proper choice of plucking may help to preserve the tea antioxidant quality.Item Open Access Influence of culture media and environmental factors on mycelial growth, sporulation and spore germination behaviour of Curvularia eragrostidis (P. Hennings) Mayer(University of North Bengal, 2008-03) Saha, A.; Dasgupta, S.; Mandal, P.; Saha, D.Curvularia eragrostidis is a foliar fungal pathogen of young tea plants. It causes leaf spot disease of tea. Mycelial growth, sporulation and spore germination behaviour of the pathogen were studied. Six different media were tested for mycelial growth. Among these, potato carrot agar (PCA) was found best for the mycelial growth and sporulation. Maximum mycelial growth was attained after 15 days of incubation. Mycelial growth was also studied in different temperatures and pH. Optimum temperature of growth was 25 °C and best growth was obtained at pH 6.0. Glucose and peptone were best carbon and nitrogen sources respectively for growth and sporulation of the fungus. The optimum conditions of spore germination were found to be at pH 7.25 and at incubation temperature of 25 °C. Keywords: Sporulation; Curvularia eragrostidis; Mycelial growth, fungusItem Open Access Searching for phosphate solubilizinz tungal isolates from soil(University of North Bengal, 2008-03) Chakraborty, B. N.; Chakraborty, U.; Saha, A.; Dey, P. L.; Sunar, K.A total of 354 fungal isolates were obtained from soil samples collected from forests, river basins and agricultural fields of North Bengal using serial dilution, direct soil plating, serial root washing and root maceration techniques. Cultural characteristics of the isolated fungi were studied and microscopic observations were made for identification of these isolates. All the isolates were screened for their phosphate solubilizing activities in vitro. A total of 70 fungal isolates showed phosphate solubilizing activities as detected in Pikovskaya's agar medium. Quantitative evaluation of phosphate solubilization in liquid medium supplemented with two phosphate sources (tricalcium phosphate and rock phosphate) was carried out for all the isolates showing phosphate solubilizing activity. Maximum phosphate solubilizing capacity was shown by three isolates of A. niger while A. clavatus showed minimum activity. Genomic DNA was extracted from sixteen isolates showing high activity and PCR amplification of DNA from nine isolates was done.Item Open Access Bacterial strain isolated from the Mango field and identified on the basis of 16S rDNA sequence information and optimization of the alkaline cellulase production(University of North Bengal, 2008-03) Roy, S.C.; Chattopadhyay, A.A bacterial strain was isolated from the soil of mango (Mangifera indica) orchards. The isolate was identified as Paenibacillus ahvei [MTCC 7809] through phylogenetic analysis based on the 16S rDNA gene sequencing and also by conventional biochemical processes. The scanning electron microscopic analysis revealed the morphological details of the strain. The isolate is Gram positive. motile, rod shaped, spore forming bacterium with extreme salt tolerance. It can hydrolyze starch and gelatin, and catalase and oxidase were produced. The cellulase activity of the culture broth was determined by measuring the reducing sugar released from carboxymethyl cellulose (CMC). Different cultural conditions were tested to reach the optimum growth conditions in order to obtain large-scale production of alkaline cellulase for commercial importance. Crude cellulase from Paenibacillus alvei (MTCC 7809) showed activity and stability at moderately high temperature and pH and the activity remained stable at 40°C and pH 8 after 2h of incubation making the strain a good choice for industrial applications. The rDNA sequence of 1509bp is submitted into the NCBI GenBank database (Acession no. EF429201).Item Open Access Resistance of Klebsormidium flaccidum (Kützing) Silva, Mattox & Blackwell (Streptophyta) to heavy metals(University of North Bengal, 2009-03) Gaysina, LA; Purina, ES; Safiullina, LM; Bakieva, GRThe influence of copper (1-10-10-2 M/L), nickel (1-10-6-1 M/L) and manganese (Ix10-1-1 M/L) chlorides on morphology of filaments and cells in Klebsormidium flaccidum (Kützing) Silva, Mattox & Blackwell (Streptophyta) were studied. Concentrations of CuCl2 (1x10-5 M/L). NiCl2 (lx10-3 M/L) and MnCl2 (Ix10-1 M/L) caused different morphological aberrations in algal cells, such as granulation, changing of cell form, damage of chloroplast, and complete destruction of the cell content. Heavy metals resulted in a decrease of K. flaccidum filament length. CuCl2 caused increase of the cell length. K. flaccidum aplanospores formation occurred at a MnCl2 concentration of 1x10-1 M/L.Item Open Access Investigation of codon and amino-acid usages in a Rhizobium phage(University of North Bengal, 2009-03) Sur, S; Bajwa, B; Bajwa, M; Basistha, B; Bothra, AK; Sen, AIn this study codon and amino-acid usage of the phage genes were analyzed to understand the functionality of the protein coding genes. Low bias was noticed. The genes were influenced by mutational bias. Reasonable number of optimal codons was noticed. GC3 content does not play any role in synonymous codon usage: however gene expression levels and hydropathicity determine codon and amino acid usage variation. Highly expressed genes play an important role in infectivity.Item Open Access A Cytogenetic Study of Seven Tea Clones [Camellia sinensis (L.) 0. Kuntze|(University of North Bengal, 2009-03) Roy, SC; Chakraborty, BNKaryotype analyses in seven cultivated clones (cv. T78, T383, TV30, HV39, TecnAli17/1/54, TV29, und UPASI-26) of tea (Camellia sinensis) are investigated for their cytogenetic characterization. Karyotypes of the chromosomes (2n = 30) were grouped arbitrarily on the basis of their length and position of the centromere into four types (A-D). Centromeric index (F %). total centromeric index (TF %), disparity index (DI) and total haploid chromosome length (TCL) were calculated. Chromosomes were found to be short to medium in size varied in length from 1.24 μm to 4.20 μm. Karyotypes were gradate and asymmetric in nature with median to nearly submedium chromosome. On the basis karyotype analysis, varietal distinction can be marked to some extent.Item Open Access Arbuscular mycorrhizal fungal association in rhizosphere of Hevea brasiliensis(University of North Bengal, 2009-03) Chakraborty, BN; Sunar, KOccurrence of VAM spores in Hevea brasiliensis growing soils and percent colonization in roots of three varieties (RRII 105, RRIM 600 and GT 1) were studied. Spore population varied from 30 to 45/g soil and the root infection of all the three varieties ranged from 70 to I00 % in both mature and young plants. Percent of root infection was found to be more in the drought resistant varieties RRII 105 followed by RRIM 600 and the less drought resistant variety GT-1. Nine different types of glomalean spores were recovered from the soil samples, including five from the genus Glomus, three from Acaulospora, one from Gigaspora and few undefined species of Sclerocystis. The scanning electron microscopic observations of the most commonly occurring spores of Glomus fasciculatum revealed smooth wall character with number of pits.Item Open Access Antioxidant and antimicrobial activities of a common liverwort from Darjeeling Himalaya(University of North Bengal, 2009-03) De, Rajib; Saha, Jayati; Sarkar, Prabir KThe study was concerned with an examination of antioxidant and antimicrobial activities of methanolic extract of Marchantia convoluta (Merch.) L.. collected from Darjeeling Himalaya. The antioxidant activities were evaluated by means of five in vitro methods, viz. free radical-scavenging activity, Fe3+ -reducing power, metal-chelating ability, trolox equivalent antioxidant capacity (TEAC) and activity in hydroxyl radical-scavenging system. The total phenol content was 1.1 mg gallic acid equivalents g-1 dried thallus. After 30 min of reaction, the 100 mg lyophilized extract possessed 6.7 % free radical-scavenging activity. The same amount of extract exhibited 13.4 % 168.2 % metal-chelating and hydroxyl radical scavenging activities, respectively. The reducing activity was found to be 28.5 mg ascorbic acid equivalents g-1 dried thallus. Total antioxidant activity was 0.18 μg TEAC g-1 dried thallus. The antimicrobial activity was evaluated by testing the methanolic extract of the samples against five microorganisms including two Gram positive bacteria (Staphylococcus aureus and Bacillus cereus), two Gram negative bacteria (Escherichia coli and Klebsiella pneumoniae) and one yeast (Candida albicans by disc-diffusion assay. M. convoluta thallus extract was more or less inhibitory against all of the test bacteria, however did not possess any antifungal property. S. aureus was found to be most sensitive target organism.