Department of Botany

Permanent URI for this communityhttps://ir.nbu.ac.in/handle/123456789/4383

Since establishment in 1984, the department flourished with tireless efforts of faculties, staff and students. The course curriculum of the department has always been strong and forward looking. Syllabi have been revised regularly and the latest version was done with the introduction of semester system offering five special papers, namely Cytogenetics, Microbiology, Molecular Plant pathology and Fungal Biotechnology, Plant Biochemistry and Taxonomy of Angiosperms and Biosystematics.

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2014 - 20152

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Author: search.filters.author.Roy, Subhas ChandraSubject: search.filters.subject.Protocorm

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Now showing 1 - 2 of 2
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    ItemOpen Access
    In vitro seed germination of an Endangered Terrestrial Orchid Species Geodorum densiflorum (Lam.) Schltr.
    (University of North Bengal, 2015-03) Roy, Subhas Chandra
    Orchid seed is rather difficult to germination rather than other angiospermic seeds, because of lack radical and endosperm, leaf rudiments. Seed germination and protocorm like body (PBL) formation of Geodorum densiflorum (Lam.) Schltr. was performed. This study was conducted to determine the effects of coconut milk (CM), and BAP for optimal media culture. Seeds from sterilized capsules were cultured on two media and MS medium (Knudson C orchid medium, KnC, containing 0 and 25% (v/v) CM and 0 and 5 mgl BAP with 0.8% (w/v) agar as material. The cultures were solidifying provided by cool white florescent maintained tubes. The highest germination percentage was observation in 15% (v/v), CM and 3 mg l-1 BAP both in MS and KnC media. Seeds germinated and formed light green globular structures on the medium after three weeks of culture. These globular structures produced Protocorm-like body (PLB) and proliferated and developed into irregular-shaped rhizomes with white hairy structures. Highest in vitro seed was found in KnC medium supplemented with 15% CM and 3 mgl-1 BAP about 95.31 % whereas in MS medium maximum cultured germination KnC reached medium at 79% with 15% CM and 3 mg BAP. Overall, this study showed that Geodorum seeds culture on KnC medium containing CM and BAP can be used for clonal propagation.
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    ItemOpen Access
    Mass Propagation of an epiphytic orchid Acampe papillosa (Lindl.) through in vitro seed germination
    (University of North Bengal, 2014-03) Roy, Subhas Chandra
    A method of in vitro propagation of a medicinally important epiphytic orchid of NBU campus Acampe papillosa has been developed. Three different categories of media (1/2 MS, MS and Knudson C) were used for in vitro asymbiotic seed germination for conservation and commercial uses. Seed germination was observed in all the media without any growth supplement or additives although not efficiently. Seeds showed positive germination response in all the three media but the frequency and onset of germination, protocorm formation and associated morphogenic changes leading to plantlets establishment varied with the nature of additional growth stimulus. Different concentrations and combinations of auxin and cytokinins were used to enhance the germination and seedling development. The different concentration of coconut water (CW) was used as additive supplement in this study and 15% CW showed good germination within 22 days in KnC medium. Various concentrations and combinations of plant growth regulators BAP (1mg l-1 to 4 mg l-1), NAA (0.5 mg l-1 to 2 mg l-1) and IBA (0.5 mg l-1 to 2 mg l-1) were added into the three categories of media as growth stimulants. The induction of PLBs was observed in the absence of any exogenous supply of PGRs, but the addition of BAP (4 mg l-1) with KnC medium improved the shoot growth significantly and enhanced the PLBs development (95% efficiency) with highest shoot length (2.5 cm) after six months of culture. Minimum number of days was required for seedling development (148 days) when cultured into the KnC medium supplement with combinations of BAP (4 mg l-1) and IBA (2 mg l-1). Addition of small quantity of NAA (0.5 mg l-1to 2 mg l-1) was not improved the PLBs or seedling development in compared to BAP and IBA. Rooting was improved by addition of IBA (0.5 mg l-1 to 2 mg l-1) into the media. High rate of rooting efficiency was recorded when combinations of auxin and cytokinin was used. Frequency of rooting (95%) was studied in KnC medium containing BAP (4 mg l-1) and IBA (2 mg l-1). Seedling of 2.5 cm long with 3-4 leaves were transferred to earthen pot containing wood charcoal and coco peat for acclimatization under green house conditions. Hardened plantlets showed significantly high survival rate (81%) after seven months of transfer. Therefore, the present method of micro-propagation could be used successfully to propagate this important orchid for commercial production and conservation purposes.