Improving androgenesis‐mediated doubled haploid production efficiency of FCV tobacco (Nicotiana tabacum L.) through in vitro colchicine application     

Salej Sood  Samresh Dwivedi  Thamalampudi Venkata Reddy  Panuganti Satya Prasanna  Navin Sharma 《Plant Breeding》2013,132(6):764-771

Production of doubled haploid plants through androgenesis in flue‐cured Virginia (FCV) tobacco is a promising and convenient alternative to conventional selfing techniques for the generation of absolute homozygous lines. Here, we show a robust in vitro haploid and doubled haploid development protocol in FCV tobacco with major emphasis on improving the efficiency of chromosome doubling using in vitro colchicine treatment. We used five FCV tobacco hybrids for comparison of colchicine treatments. The anther culture response varied with developmental stages of the buds, and the highest response was observed in stage 2 buds. The effect of cold pretreatment was significant, and 4 days of pretreatment was optimum for gametic embryogenesis. Among the methods used for determining the ploidy status of plants, flow cytometry was found to be easy, fast and reliable for high‐throughput screening of haploids. Doubled haploids regeneration percentage varied from 6.77 to 11.95 in in vivo treatment, while the range of variation was 22.11% to 28.40% in in vitro colchicine treatment. We observed a pronounced increase in plant survival and the proportion of doubled haploid plants in in vitro treatment compared with the standard in vivo approach.  相似文献   

Porcine reproductive and respiratory syndrome virus induces pronounced immune modulatory responses at mucosal tissues in the parental vaccine strain VR2332 infected pigs     

Cordelia Manickam  Varun Dwivedi  Ruthi Patterson  Tracey Papenfuss  Gourapura J. Renukaradhya 《Veterinary microbiology》2013

Porcine reproductive and respiratory syndrome (PRRS) is a chronic viral disease of pigs caused by PRRS virus (PRRSV). The PRRSV VR2332 is the prototype North American parental strain commonly used in the preparation of vaccines. Goal of this study was to understand missing information on VR2332 induced immune modulation at the lungs and lymphoid tissues, the sites of PRRSV replication. Pigs were infected intranasally and samples collected at post-infection day (PID) 15, 30, and 60. Microscopically, lungs had moderate interstitial pneumonia, and the virus was detected in all the tested tissues. Peak antibody response and the cytokine IFN-γ secretion were detected at PID 30, with increased TGF-β until PID 60. Population of CD8⁺, CD4⁺, and CD4⁺CD8⁺T cells, Natural killer (NK) cells, and γδ T cells in the lungs and lymphoid tissues were significantly modulated favoring PRRSV persistence. The NK cell-mediated cytotoxicity was significantly reduced in infected pigs. In addition, increased population of immunosuppressive T-regulatory cells (Tregs) and associated cytokines were also observed in VR2332 strain infected pigs.  相似文献   

Impact of Thermal Processing on Legume Allergens     

Alok Kumar Verma  Sandeep Kumar  Mukul Das  Premendra D. Dwivedi 《Plant foods for human nutrition (Dordrecht, Netherlands)》2012,67(4):430-441

Food induced allergic manifestations are reported from several parts of the world. Food proteins exert their allergenic potential by absorption through the gastrointestinal tract and can even induce life threatening anaphylaxis reactions. Among all food allergens, legume allergens play an important role in induction of allergy because legumes are a major source of protein for vegetarians. Most of the legumes are cooked either by boiling, roasting or frying before consumption, which can be considered a form of thermal treatment. Thermal processing may also include autoclaving, microwave heating, blanching, pasteurization, canning, or steaming. Thermal processing of legumes may reduce, eliminate or enhance the allergenic potential of a respective legume. In most of the cases, minimization of allergenic potential on thermal treatment has generally been reported. Thus, thermal processing can be considered an important tool by indirectly prevent allergenicity in susceptible individuals, thereby reducing treatment costs and reducing industry/office/school absence in case of working population/school going children. The present review attempts to explore various possibilities of reducing or eliminating allergenicity of leguminous food using different methods of thermal processing. Further, this review summarizes different methods of food processing, major legumes and their predominant allergenic proteins, thermal treatment and its relation with antigenicity, effect of thermal processing on legume allergens; also suggests a path that may be taken for future research to reduce the allergenicity using conventional/nonconventional methods.  相似文献   

Chemopreventive Effects of Sarcophine-diol on Ultraviolet B-induced Skin Tumor Development in SKH-1 Hairless Mice     

Xiaoying Zhang  Ajay Bommareddy  Wei Chen  Michael B. Hildreth  Radhey S. Kaushik  David Zeman  Sherief Khalifa  Hesham Fahmy  Chandradhar Dwivedi 《Marine drugs》2009,7(2):153-165

Sarcophine-diol (SD), one of the structural modifications of sarcophine, has shown chemopreventive effects on 12-dimethylbenz(a)anthracene-initiated and 12-O-tetradecanoylphorbol-13-acetate-promoted skin tumor development in female CD-1 mice. The objective of this study was to determine the chemopreventive effects of SD on UVB-induced skin tumor development in hairless SKH-1 mice, a model more relevant to human skin cancer, and to determine the possible mechanisms of action. Carcinogenesis was initiated and promoted by UVB radiation. Female hairless SKH-1 mice were divided into two groups having 27 mice in each group: control and SD treatment. The control group was topically treated with 100 μL acetone and SD treatment group was topically treated with SD (30 μg/100 μL in acetone) 1 hour before each UVB radiation for 32 weeks. Tumor counts were recorded on a weekly basis for 30 weeks. Effects of SD on the expression of caspases were investigated to elucidate the possible mechanism of action. The proteins from epidermal homogenates of experimental mice were used for SDS-PAGE and Western blotting using specific antibodies against caspase-3, caspase-8 and caspase-9 respectively. TUNEL assay was used for determining DNA fragmented apoptotic cells in situ. Results showed that at the end of experiment, tumor multiplicity in control and SD treatment groups was 25.8 and 16.5 tumors per mouse respectively. Furthermore, Topical treatment of SD induced DNA fragmented apoptotic cells by upgrading the expressions of cleaved caspase-3 and caspase-8. This study clearly suggested that SD could be an effective chemopreventive agent for UVB-induced skin cancer by inducing caspase dependent apoptosis.  相似文献   

Chemical Fractions of Mn in Acidic Soils and Selection of Suitable Soil Extractants for Assessing Mn Availability to Maize (Zea Mays L.)     

Dibya Joshi  Rama Dwivedi  Satya P. Pachauri  Arvind K. Shukla 《Communications in Soil Science and Plant Analysis》2017,48(8):886-897

Twenty surface (0–15 cm) samples of acidic soils were analyzed for water soluble (WS), exchangeable (EX), lead displaceable (Pb-disp.), acid soluble (AS), manganese (Mn) oxide occluded (MnOX), organically bound (OB), amorphous Fe oxide occluded (AFeOX), crystalline iron (Fe) oxide occluded (CFeOX) and residual (RES) fractions of Mn, and also for extractable Mn in some common soil extractants: (diethylenetriaminepentaacetic acid (DTPA) (pH 7.3), DTPA (pH 5.3), AB-DTPA (pH 7.6), Mehlich-3 (pH 2.0), Modified Olsen, 0.005 M calcium chloride (CaCl₂), 1 M magnesium chloride (MgCl₂) and ion exchange resins. The WS-Mn fraction showed a significant and positive correlation with Mn extractable in DTPA (pH 5.3) and AB-DTPA (pH 7.6), while both WS-Mn and EX-Mn fractions correlated significantly and positively with Mn concentration and uptake by maize plants grown in these soils. The AB-DTPA (pH 7.6) and DTPA (pH 5.3) appeared suitable to assess the availability of Mn in acidic soils.  相似文献   

Investigation on ion conduction behaviour in Zn-ferrite based polymer nanocomposite electrolyte     

S. L. Agrawal  Markandey Singh  Mrigank Mauli Dwivedi  Kamlesh Pandey 《Fibers and Polymers》2011,12(7):864-874

Present paper deals with, improvement in ion transport property and dielectric relaxation of polyethylene oxide (PEO)-based polymer electrolytes subsequent to dispersal of nanosized Zn-ferrite filler particles. The nanocomposite polymer electrolyte (NCPE) system [93PEO:7NH₄SCN]: x% Zn-ferrite was prepared by solution cast technique through dispersal of sol gel derived Zn-ferrite nano powder in the pristine polymer electrolyte solution. The structural and morphological behavior of NCPEs have been studied by XRD, SEM, IR and DSC measurements. Electrical conductivity (both a.c. & d.c.) measurement on nanocomposite polymer electrolyte sample have been carried out using impedance spectroscopic technique. Dielectric relaxation studies were extracted by impedance data. The hopping ion transport mechanism in NCPEs has been concluded with the help of dielectric and modulus formalism.  相似文献   

Evaluation of zincated nanoclay polymer composite in releasing Zn and P and effect on soil enzyme activities in a wheat rhizosphere     

Nintu Mandal  Samar C. Datta  Kanchikeri M. Manjaiah  Brahma S. Dwivedi  Rajesh Kumar  Pramila Aggarwal 《European Journal of Soil Science》2019,70(6):1164-1182

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Agro-morphological characterization of ovary culture-derived plants of rice (Oryza sativa L.)   总被引：2，自引：0，他引：2  

Li Rongbai  M.P. Pandey  S.K. Pandey  D.K. Dwivedi 《Euphytica》1999,106(3):197-203

Plants derived from unpollinated ovary culture of ten rice genotypes showed significant variability in agro-morphological characteristics. The ovary-derived plant (H1) populations were completely haploid, doubled haploid or haploid-doubled haploid mixture. Haploids had very drastic reduction in plant height, panicle length, grain length, breadth and number and spikelet fertility (0.0%–2.1%). Doubled haploids from the hybrid of UPRI 95–121 × UPRI 95–165 were normal with fertility ranging between 69.6% and 97.7%. A genetic segregation in ratio of 1:1 was observed for five pigmentation characters in the H1 population derived from hybrid UPRI 95–122 × UPRI 95–165. Plant height showed the largest coefficient of variability (28.5%) followed by the number of spikelets per panicle (24.2%), number of grains per panicle (22.0%), percent seed set (9.2%) and panicle length (9.0%). The range of variation in the H1 population from fully fertile hybrid PMS 2A (CMS) × IR 31802 (restorer) was similar to its corresponding F2 population for plant height, spikelet fertility and number of grains/panicle. A single clone of plants from the cultivar BG 1321 exhibited complete male sterility but normal female fertility when pollinated with other varieties. Ovary-derived plants from the CMS lines PMS 2A and IR 58025A showed stable male sterility and those from thermosensitive genetic male sterile line UPRI 95–140 showed thermosensitive genetic male sterility. These lines have potential in the hybrid breeding program and are being currently exploited. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Validation of SCAR markers,diversity analysis of male sterile (S-) cytoplasms and isolation of an alloplasmic S-cytoplasm in Capsicum     

Rajesh Kumar  Sanjay Kumar  Neeraj Dwivedi  Sanjeet Kumar  Ashutosh Rai  Major Singh  Dasrath Singh Yadav  Mathura Rai 《Scientia Horticulturae》2009

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Histopathological Observations in Guava Root during Wilting caused by Fusarium Species: A Scanning Electron Microscopy Study     

Neetu Dwivedi  S. K. Dwivedi 《International Journal of Fruit Science》2016,16(3):335-340

Fusarium oxysporum and Fusarium solani are the two most destructive pathogens causing wilt disease in guava (Psidium guajava L.) commonly known as ‘super fruits’. These pathogens attack mainly on the root region of the plant and cause severe infection. In the present investigation the infection process was studied with scanning electron microscopy (SEM) and it was observed that the root region of the guava plant showed disintegration and necrosis in the epidermal layer, cortex tissue, and in vascular bundles, while the root region of a healthy sapling showed no such changes. The rupturing of the epidermal layer may show the entry of pathogens in the host tissue through the secretion of toxic enzymes/metabolites. These toxins have great potential to cause wilting symptoms in guava plants in the form of necrosis. Wilt disease causes huge losses in guava production in both tropical and subtropical countries. Therefore, there is a need to find the responsible factors. The present study is an attempt to understand the interaction mechanism of phyto-pathogens causing wilt disease.  相似文献