NBU Journal of Plant Sciences, Vol. 03
Permanent URI for this collectionhttps://ir.nbu.ac.in/handle/123456789/4405
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Item Open Access Change of vegetation structure in Gorumara National Park due to anthropogenic interferences(University of North Bengal, 2009-03) Sarkar, A; Sarkar, S; Das, APThe impact of Human intervention on species composition, biomass and soil structure in the exploited and unexploited areas of Shorea robusta forest in a part of Gorumara National Park has been evaluated. The areas are adjacent to the Bichhabhanga-Saraswati Eco-Development Committee. The tree species are identical to both areas but differ in their density, frequency and IVI. Tree biomass is smaller in disturbed areas as compared to non-disturbed areas. Due to over exploitation changes occurred in the physical characters of soil. Crown cover also varies significantly within the two sites.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 Pathogenesis-related proteins of tea triggered by Exobasidium vexans(University of North Bengal, 2009-03) Chakraborty, BN; Sharma, M; Das Biswas, R; Ghosh, ANThe defense strategy of tea plants against Exobasidium vexans are multifold and include accumulation of pathogenesis-related (PR) proteins. A study on the association of defense enzymes with resistance in tea plants triggered by E. vexans revealed significant changes in the level of β-1.3-glucanase (PR 2) and chitinase (PR 3) exhibiting antimicrobial activity. Accumulation of defense proteins differed in time and magnitude. Time course studies points towards accumulation of PR-2 and PR-3 in the early hours, PR-9 later on and finally the antifungal metabolites that confer resistance to the plants. Treatment with salicylic acid (SA) stimulates a multicomponent defense response in tea leaves which was confirmed by immuno-localization of PR 2 and PR 3 in tea leaf tissues following induction of resistance. Induction of PR-3 in suspension-cultured tea cells following SA treatment was confirmed immunologically using antibody probes (PAb-chitnase). Subcellular localization of PR-3 and PR-2 in tea leaves were also confirmed by indirect immunogold labeling. Marked increase in frequency of gold particles following elicitation by SA treatment was evident. Cell defense responses associated with systemic acquired resistance induced by SA against E.vexans has been discussed in relation to the possible role of PR-proteins in immunizing tea plantsItem Open Access Role of germination induced peptide pool in plant tissue culture(University of North Bengal, 2009-03) Mandal, P; Misra, TK; Ghosh, A; Sircar, PKLow molecular weight peptides (ranges from 3.0 KDa to 0.5 KDa) were extracted and purified from rice, wheat, chickpea and mungbean through cryocrushing, cold centrifugation, ether fractionation, cation and anion-exchange column chromatographic separation, lyophilisation and ultrafiltration. The profile of heterogeneous peptides was detected through one dimensional paper chromatography. Peptüde fractions isolated from different germination hours of mungbean enhanced mitotic index, more particularly prophase of root tip of Alium cepa L and excuted definite control over morphogenesis of excised and cotyledonary embryo culture of chick-pea seeds (Cicer arietinum L.). Restricted callogenesis in carrot pith culture was observed by the application of wheat peptides without any other hormones. Our speculation is that the peptides can mimic the action of hormone and behave as novel kind of bioactive molecule through which the physiological responses can be modulated.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 Heat acelimation and chemical pre-treatments induccd thermotolerancc in chickpea(University of North Bengal, 2009-03) Tongden, C; Chakraborty, UInduced heat-tolerance triggered by heat acclimation treatment and foliar application of salicylic acid and abscisic acid were evaluated in three different genotypes of chickpea (Cicer arietinum L.) distinctly differing in their sensitivity to heat stress. Seedlings pre-treated with 100uM salicylic acid (SA) and 50 uM abscisic acid (ABA) showed improved heat tolerance to a lethal temperature of 46°C than the untreated control seedlings. Heat stress increased lipid peroxidation of membranes and reduced plant survival. Protein and proline contents increased significantly in pre-treated seedlings. Cell membrane stability also increased remarkably in pre-treated seedlings of all three genotypes. Changes in activities of antioxidative enzymes like peroxidase, ascorbate peroxidase in pre-treated seedlings revealed increase in enzymatic activities which declined sharply at lethal temperuturc. Quantum of increase in enzymatic activity was however higher in thermotolerant genotype in comparison to heat susceptible genotype. Thermotolerant genotype also exhibited constitutively higher antioxidative activities. Catalase activity, in contrast, showed a significant decrease in its activity in pre-treated seedlings following exposure to lethal temperature. These results indicate that heat acclimation treatment and application of SA and ABA show great potential in inducing heat tolerance in chickpea seedlings and these can be further analyzed to understand their role in thermoprotection.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 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.Item Open Access Antidiabetic and anti-oxidant activity of Moringa oleifera leaf extract in streptozotocin induced diabetic rats(University of North Bengal, 2009-03) Chakraborty, U; Das, HThe effect of the aqueous extract of Moringa oleifera Lamk. leaves (MOLE) in the treatment of diabetes along with its antioxidant activity in streptozotocin induced diabetic rats was determined in the current study. Oral administration of MOLEt @ 125 and 250 mg/kg for 20 days significantly prevented the STZ- induced hyperglycemia. Administration of the extracts at the dose of 250 mg/kg body weight/day resulted in a marked decrease in the levels of fasting blood glucose and urine sugar. The extract also produced a significant decrease in peroxidation products, viz.. thiobarbituric acid reactive substances. The activity of reduced glutathione and glycogen content were found to be increased in the hepatic tissue of SiZ- diabetic rats treated with MOLEL. STZ-diabetic rats treated with MOLEt significantly reversed all these changes to near normal. The MOLBt thus exhibits antidiabetic and anti-oxidative activity in STZ-induced diabetic rats.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.