197 research outputs found

    In vitro effects of regulators on growth and morphogenesis of Ocimum basilicum L. ‘Alfavaca Green’ stem apexes

    Get PDF
    Large-scale cultivation of contamination free plants requires a good standardization protocol and production methods. Basil is widely used for cosmetics, food and pharmaceutical industries as it is rich in many bioactive compounds. This present study aimed to evaluate the growth and in vitro anatomical aspects of apical buds of basil grown under different concentrations rowth regulators like: NAA (Naphthalenoacetic Acid), BAP (6-benzylaminopurine), and KIN (Kinetin). The in vitro establishment was evaluated every 20 days to calculate the, the percentage of plants with calluses, appearance of the roots, any abnormal seedlings, any oxidized seedlings, and the number of sprouts per plant. Growth, physiological, and morpho-anatomical evaluations were performed at 80 days. Basal callogenesis was observed when cytokinin’s and auxins are used in combination. Auxin treatments caused hyperhydricity in the stems and leaves. Medium A2 (0.05 mg L -1 of NAA and 0.1 mg L -1 of BAP), and A3 (0.05 mg L -1 of NAA and 0.1 mg L -1 of KIN) resulted in the best development of basil plants, cultivar ‘Alfavaca Green’. The A2 produced plants with greater numbers of leaves, an average bud length of 59.81 mm, and the best root properties. A2 and A1 have a higher percentage of hyperhydricity (83 and 67%). The A3 resulted in an acceptable number of leaves (range: 21–39), and this treatment produced the best shoot properties as well as fewer plants with hyperhydricity. In addition, the A3 treatment produced plants with a shoot length, high shoot fresh and dry mass (2.82 and 0.23 g), high chlorophyll index and leaf anatomy that was similar to the control. Excluding the control, the other treatments presented more than 90% of the explants with calluses in their bases

    Copper modulates the biochemical and enzymatic activity and growth of tomato cultivars grown in vitro

    Get PDF
    Received: August 25th, 2020 ; Accepted: December 17th, 2020 ; Published: February 09th, 2021 ; Correspondence: [email protected] (Cu) is a micronutrient that is neglected for tomato growth. This study sought to identify the effects of exposure to Cu on the growth and biochemical activity of two tomato cultivars. Tomato seeds of ‘Carolina’ and ‘Cereja’ cultivars were disinfected and inoculated in MS medium plus copper sulfate concentrations (CuSO4) (default MS, 25, 50, and 100 µm) and had their growth monitored for 30 days. It was estimated that the growth and biomass accumulation of tomato plants ‘Carolina’ and ‘Cereja’, both from the aerial part and the roots, were benefited by 25 e 50 µm of CuSO4. However, it was observed that these concentrations were inefficient in controlling hyperhydricity and leaf deformation. There was a reduction of these phenomena in the treatment with 100 µm, in both cultivars. Tomato of ‘Carolina’ cultivar subjected to 100 µm showed an increase in anthocyanins and superoxide dismutase (SOD) activity in the root system. There was a reduction of catalase (CAT) activity in shoots exposed to Cu. ‘Cereja’ tomatoes subjected to 100 µm showed an increase in CAT and SOD activity in shoots and roots, respectively. It was concluded that the ‘Carolina’ and ‘Cereja’ tomatoes have their growth impaired when exposed to 100 µm CuSO4. Concentrations higher than 50 µm of CuSO4 cause an increase in the antioxidant activity in the shoot of tomato plants from the ‘Carolina’ cultivar. Concentrations higher than 50 µm CuSO4 increase SOD activity in the root system of tomato plants from the ‘Cereja’ cultivar

    Characterization of anti-crotalic antibodies

    Get PDF
    AbstractCrotalus durissus terrificus, C. d. collilineatus, C. d. cascavella and C. d. marajoensis are responsible minor but severe snake bites in Brazil. The venoms of these snakes share the presence of crotoxin, a neurotoxin comprising of two associated components, crotapotin and phospholipase A2 (PLA2). Treatment of the victims with specific antiserum is the unique effective therapeutic measure. The ability of anti-Crotalus antisera produced by the routine using crude venom to immunize horses or purified crotoxin and PLA2 as individual immunogens was compared. Antisera obtained from horses immunized with C. durissus terrificus crude venom were able to recognize and neutralize not only the toxins presents in C. durissus terrificus, but also the ones present in the venoms from C. d. collilineatus, C. d. cascavella and C. d. marajoensis. Antisera from horses immunized with individual crotoxin or PLA2, although in lesser titers, were also able of recognizing the toxins in all four Crotalus species and neutralize the lethality of the C. d. terrificus venom

    Crackling Noise, Power Spectra and Disorder Induced Critical Scaling

    Full text link
    Crackling noise is observed in many disordered non-equilibrium systems in response to slowly changing external conditions. Examples range from Barkhausen noise in magnets to acoustic emission in martensites to earthquakes. Using the non-equilibrium random field Ising model, we derive universal scaling predictions for the dependence of the associated power spectra on the disorder and field sweep rate, near an underlying disorder-induced non-equilibrium critical point. Our theory applies to certain systems in which the crackling noise results from avalanche-like response to a (slowly) increasing external driving force, and is characterized by a broad power law scaling regime of the power spectra. We compute the critical exponents and discuss the relevance of the results to experiments.Comment: 27 Latex Pages, 14 eps figure

    Absolute Configuration of a Tetrahydrophenanthrene from Heliotropium ovalifolium by LC-NMR of Its Mosher Esters

    Get PDF
    A new tetrahydrophenanthrene (1, (1R,2R)-1-hydroxy-2-methoxy-6,9-dimethyl-2,3-dihydrophenanthren-4(1H)-one (heliophenanthrone)) has been isolated from the aerial parts of Heliotropium ovalifolium. Its structure was elucidated on the basis of spectroscopic data, and the absolute configuration of the asymmetric centers was determined from LC-NMR data of the Mosher ester derivatives

    Fermionic Casimir effect with helix boundary condition

    Full text link
    In this paper, we consider the fermionic Casimir effect under a new type of space-time topology using the concept of quotient topology. The relation between the new topology and that in Ref. \cite{Feng,Zhai3} is something like that between a M\"obius strip and a cylindric. We obtain the exact results of the Casimir energy and force for the massless and massive Dirac fields in the (D+1D+1)-dimensional space-time. For both massless and massive cases, there is a Z2Z_2 symmetry for the Casimir energy. To see the effect of the mass, we compare the result with that of the massless one and we found that the Casimir force approaches the result of the force in the massless case when the mass tends to zero and vanishes when the mass tends to infinity.Comment: 7 pages, 4 figures, published in Eur. Phys. J.
    • …
    corecore