Browsing by Author "Chakraborty, B.N."

Now showing 1 - 6 of 6

Open Access
Antioxidative responses of mandarin plants to water stress
(University of North Bengal, 2013-03) Allay, S.; Lama, R.; Chakraborty, U.; Chakraborty, B.N.
Citrus reticulata grows in warm climatic conditions. Stresses such as water logging, drought, soil acidity, unbalanced nutrition and pathogenic infestation lead to root injury resulting in citrus tree decline and therefore huge economic losses. In order to determine the effect of flooding and drought on mandarin plants, mandarin plants were subjected to water logging condition in the field and in pots for drought condition. Biochemical and morphological changes induced by water logging and drought conditions were determined. The plants showed slight wilting and leaf dropping by the third day of flooding whereas in drought the leaves curled up, became crisp and later dried out. Marked changes in antioxidative enzymes such as peroxidase, catalase and ascorbate peroxidase was observed during stress in comparison to control plants. Antioxidative activity was seen to be more in the leaves than in the roots. Among the antioxidants carotenoid content showed a significant decrease during the flood stress but increased in drought stress. An increase in ascorbate content was observed during stress in comparison to the control. From this study, we can conclude that water stress causes adjustment of antioxidant balance in mandarin plants.
Open Access
Association of AM fungi in the rhizosphere of Thuja orientalis (L)
(University of North Bengal, 2013-03) De, U.K.; Das Biswas, R.; Chakraborty, B.N.
Thuja orientalis (L) is used as an ornamental plant as well as medicinal plant in India from prehistoric times and instances were found in various manuscripts revealing its medicinal property against abdominal pain, hook worms, arthritis etc. AMF associated with rhizosphere of Thuja were extensively studied in relation to their population in soil, root-length colonization, histopathological study as well as their diversification. Predominant existence of various species of Glomus, Gigaspora were determined and their spore surface texture was examined using stereo microscope, besides, species of Acaulospora, Scutellospora etc. were also documented. Histopathological studies of host roots showed various types of hyphal network and arbuscules, AMF were tried to identify up to species level with the help of standard keys. The result indicated that the various spp. of AMF have established their colonization in host roots and the host plant have a significant role in root tissue colonization.
Open Access
Management of grey blight disease of Som plants using value added vermicompost with Glomus constrictum and Bacillus altitudinis
(University of North Bengal, 2015-03) Acharya, A.; Chakraborty, U.; Ghosh, S.; Chakraborty, B.N.
Grey blight disease caused by Pestalotiopsis disseminata, is one of the major foliar fungal diseases that constantly affects Persea bombycina Kost, a primary host plant of muga silkworm. Under nursery condition, grey blight disease was recorded mostly in SS and S6 morphotypes of som plants. Vermicompost, PGPR and AMF, alone and in combination were applied for the improvement of the growth of eight morphotypes of som plant as well as to reduce incidence. Growth in terms of height (cm), no. of leaves and no. of branches were studied. Analysis of some major defence related enzymes such as POX, PAL, CHT and GLU was also carried out to check induction of resistance after treatment. Artificial inoculation of som plants under nursery condition with spore suspension of P. disseminata was performed and disease progression noted for 7, 14, 21 and 28 days. It was clearly seen that disease progression was slow and less in treated inoculated plants. The results emphasize the fact that application of bioinoculants can be studied in larger scale for the upliftment of the health status of muga host plants.
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.
Open Access
Root colonization of mandarin plants grown in orchards of Darjeeling hills and plains with arbuscular mycorrhizal fungi and their effects on plant growth
(University of North Bengal, 2012-03) Allay, S.; De, U.K.; Chakraborty, B.N.
Citrus reticulata is an ancient commercial crop being cultivated in Darjeeling-Sikkim hills. Many diseases are prevalent in mandarin plants, out of them, bacterial & fungal diseases are mostly dangerous. Arbuscular Mycorrhizal Fungi were screened from rhizosphere of mandarin plants from the four different regions using wet sieving and decanting method. Microscopical observation revealed the presence of different genus of AM fungi present in the root as hyphae, spores and sporocarp. Glomus mosseae, G. fasciculatum, G. aggregatum, G. badium. G. constrictum, G. versiforme, Gigaspora gigantea, G. margarita, Acaulospora capsicula, A. bireticulata, Sclerocystis and Scutellospora rubra were found to be dominant in all the soil samples of mandarin. Species of Glomus were found to be high in both hilly and foothill regions. Glomus mosseae and G. fasciculatum were selected for mass multiplication in maize plant in pots. Histopathological study of root showed the presence of vesicles and arbuscules. AMF infection and total number of spores per 100 gram of soil were recorded. Scanning Electron Microscopy (SEM) of AMF spores of mandarin revealed clear morphology, spore wall characters and hyphal attachment of spores. Total phosphate content of the soil, soil analysis and enzyme activities in roots and leaves of mandarin plant from the different regions were studied. Three major defense enzymes peroxidase, chitinase and β- 1,3- glucanase showed enhanced activities and the total phosphate content also decreased in soil with respect to control. Present study evaluates the effect of AMF in plant growth and phosphate solubilization.
Open Access
Serological and molecular detection of Macrophomina phaseolina, causing root rot of Citrus reticulata
(University of North Bengal, 2012-03) Chakraborty, B.N.; Chakraborty, U.; Rai, K.; Sunar, K.; Dey, P.L.
Polyclonal antibodies (PAbs) were raised against mycelial antigens of Macrophomina phaseolina a causal organism of root rot disease of mandarin plants. IgG was purified and further packaged into immunological formats such as immuno diffusion, Plate trapped antigen (PTA)-ELISA, dot immunobinding assay, Western blot analysis and indirect immunofluorescence for quick and accurate detection of pathogen from soil. Indirect staining of mycelia and sclerotia of M. phaseolina with homologous PAb and labeling with goat antirabbit IgG conjugated with FITC developed strong fluorescence in young hyphal tips and sclerotia of M. phaseolina. Genomic DNA prepared from mycelia of M. phaseolina was purified and PCR amplification of 18S rDNA was done using ITS region specific primer pair. The amplified DNA was sequenced and aligned against ex-type strain sequences from NCBI GenBank using BLAST and phylogenetic analysis was obtained using MEGA4 software. Amplification of ITSI region of the rDNA can be considered as a rapid technique for identifying pathogens successfully in all cases.