Sanghamitra Nayak

Bio: Sanghamitra Nayak is an academic researcher from Siksha O Anusandhan University. The author has contributed to research in topics: Essential oil & Curcuma. The author has an hindex of 24, co-authored 152 publications receiving 2299 citations. Previous affiliations of Sanghamitra Nayak include Jaypee University of Information Technology.

Gene pyramiding-a broad spectrum technique for developing durable stress resistance in crops.

Abstract: The development of molecular genetics and associated technology like MAS has led to the emergence of a new field in plant breeding-Gene pyramiding. Pyramiding entails stacking multiple genes leading to the simultaneous expression of more than one gene in a variety to develop durable resistance expression. Gene pyramiding is gaining considerable importance as it would improve the efficiency of plant breeding leading to the development of genetic stocks and precise development of broad spectrum resistance capabilities. The success of gene pyramiding depends upon several critical factors, including the number of genes to be transferred, the distance between the target genes and flanking markers, the number of genotype selected in each breeding generation, the nature of germplasm etc. Innovative tools such as DNA chips, micro arrays, SNPs are making rapid strides, aiming towards assessing the gene functions through genome wide experimental approaches. The power and efficiency of genotyping are expected to improve in the coming decades. The present review discusses the design parameters in a gene pyramiding scheme, potential application of gene pyramiding in crop plant improvement, and the prospect and challenges in integrating MAS based gene pyramiding with conventional plant breeding programmes. Key words: Gene pyramiding, marker-assisted selection, durable resistance

Antimicrobial assay of Stevia rebaudiana Bertoni leaf extracts against 10 pathogens

Abstract: an objective of understanding the antimicrobial potential of Stevia rebaudiana (popularly called as Stevia and synonymously known as 'sugar substitute' belongs to family Asteraceae), chemical extracts from its leaves were subjected to microbial assay using six solvents against ten selected pathogenic as well as food spoiling fungal (Alternaria solani, Helminthosporium solani, Aspergillus niger, Penicillium chrysogenum) and pathogenic bacterial (Escherichia coli, Bacillus subtilis, Enterococcus faecalis, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus) isolates. 250μg/ml of petroleum ether extract (minimum inhibitory concentration) was found sufficient enough to inhibit the growth of test microorganism E.coli completely in petriplates (by plate dilution method). S. aureus amongst bacteria and P. chrysogenum amongst fungi exhibited highest range of susceptibility against four extracts namely; water, petroleum ether, cyclo-hexane, and chloroform but B. subtilis was found to have highest resistance to all except petroleum ether and acetone extract. Highest antifungal index (AfI-15mm) and antibacterial index (AbI-11.2mm) was obtained for petroleum ether extract against all pathogens signifying its best antimicrobial potentiality but ethanol and cyclo-hexane extracts were proved to be least effective (lowest AbI and AfI). Invariably cyclo-hexane, acetone and ethanol did not show anti fungal activity except demonstrating selective inhibition to specific microorganisms P. chrysogenum 8.0mm), A. solani (7.0mm) and A. niger (9.0mm) respectively. The above findings support the idea that plant extracts of Stevia rebaudiana Bertoni leaves may have a role to be used as pharmaceuticals and/or preservatives.

In vitro multiplication and microrhizome induction in Curcuma aromatica Salisb.

Abstract: Shoot multiplication and plant regeneration was achieved from freshly sprouted shoots of Curcuma aromatica on Murashige and Skoog's medium supplemented with BA alone (1–7 mgL−1) or a combination of BA(1–5 mgL−1) and Kn (0.5–1 mgL−1). A concentration of 5 mgL−1 BA was optimum for shoot multiplication and rooting of shoots. The regenerated plants grew profusely on transfer to liquid medium.In vitro raised plants were successfully established in the field. Microrhizomes were induced at the base of the in vitro derived shoots upon transfer to medium containingvarious combinations and concentrations of sucrose and BA and grown under varying photoperiods. MS basal medium with 5 mgL−1 BA, 60 gL−1 sucrose and an8 h photoperiod was optimum for induction ofmicrorhizomes within 30 days of culture. Harvestedmicrorhizomes stored in moist sand in poly-bagssprouted after 2 months of storage at roomtemperature. For in vitro storage, microrhizomeswere grown in medium containing 0.1 mgL−1 BA.Microrhizome formation was found to be controlled bythe concentrations of BA and sucrose as well asphotoperiod during culture.

“Bioinformatics” 특집을 내면서

Abstract: BIOE 402. Medical Technology Assessment. 2 or 3 hours. Bioentrepreneur course. Assessment of medical technology in the context of commercialization. Objectives, competition, market share, funding, pricing, manufacturing, growth, and intellectual property; many issues unique to biomedical products. Course Information: 2 undergraduate hours. 3 graduate hours. Prerequisite(s): Junior standing or above and consent of the instructor.

Phytochemicals: Extraction, Isolation, and Identification of Bioactive Compounds from Plant Extracts

Abstract: There are concerns about using synthetic phenolic antioxidants such as butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA) as food additives because of the reported negative effects on human health. Thus, a replacement of these synthetics by antioxidant extractions from various foods has been proposed. More than 8000 different phenolic compounds have been characterized; fruits and vegetables are the prime sources of natural antioxidants. In order to extract, measure, and identify bioactive compounds from a wide variety of fruits and vegetables, researchers use multiple techniques and methods. This review includes a brief description of a wide range of different assays. The antioxidant, antimicrobial, and anticancer properties of phenolic natural products from fruits and vegetables are also discussed.

Plant Cell, Tissue and Organ Culture

Abstract: The origin of plant cell and tissue culture can be found in a treatise published during the mid-18th century, entitled La Physique des Arbes, that describes the formation of callus tissue following the for mation of a ring of cortex from elm trees. Over the next two centuries, the discovery of plant growth hormones, in particular auxins and cytokinins, and detailed analyses on the nutritional requirements of plants, led to the formulation of media that could maintain actively dividing cultures derived from gymnosperms, and both dicotyledon ous and monocotyledonous angiosperms. However, much of the prog ress and technological development in the in vitro propagation of plant cells, tissues, and organs has occurred during the last 25 years. Recently, plant tissue culture techniques have been used as basic tools in the rapidly expanding field of plant biotechnology for the development and clonal propagation of new and/or improved plant varieties. Plant tissue culture is used for the micropropagation of commercially valuable cultivars that include ornamentals, oil palm, Glycyrrhiza, Pyrethrum, pine, Eucalyptus, sugar cane, and potatoes. Cultured plant tissue is also used for the selection of cells and, ul timately, the regeneration of plants that are tolerant to physical stresses such as pathogens, drought, and temperature extremes, and to chemical stress agents such as salinity, herbicides, proteins, and pyrethrins. In addition, new plants have been produced by the fusion of protoplasts prepared from cultured cells of different species in cluding sunflower and french bean, tomato and potato, and various cultivars of Datura. Finally, bacterial vectors and various mechanical methods have been used to introduce foreign genes into cultured plant tissues. Genetic transformation can result in profound changes in the phenotype and/or biochemical profile of the regenerated trans genic plants that are not characteristic of the wild type. An impressive variety of technologies in tissue culture, genetic manipulation, and molecular biology have been developed for nu merous plant species. Many of these techniques, sometimes referred to as plant biotechnology, have been extensively summarized and compiled in a well-balanced collection of easy-to-follow protocols presented in three separate, but complimentary, volumes. Plant Cell, Tissue and Organ Culture consists of 22 chapters (with 86 figures) and 5 appendices. The chapters cover critical aspects of (a) the es sential requirements for the operation of a plant tissue culture lab oratory; (b) the basic procedures of micropropagation, regeneration, and somatic embryogenesis; (c) some specific applications of organ culture systems such as embryo rescue and culture, and anther and microspore culture for haploid and double haploid production; (d) elementary transformation technology; and (e) useful microtechnique and analytical protocols specifically adapted to cultured tissues and cells. The appendices provide a convenient summary of media for mulations and commercial suppliers for the materials described in the text.