Micropropagation of Withania somnifera from germinating seeds and shoot tips
TL;DR: Shoot multiplication was achieved in vitro from shoot tips of aseptically germinated seedlings of Withania somnifera L. with direct multiple shoot initiation from germinating seeds in the presence of BA alone.
Abstract: Shoot multiplication was achieved in vitro from shoot tips of aseptically germinated seedlings of Withania somnifera L. using low concentrations of 6-benzyladenine (BA), viz. 2.2, 4.4 and 8.9 μM. Maximum number of shoots were obtained when 2.3 μM 2,4-dichlorophenoxyacetic acid (2,4-D) or 2.5 μM indolebutyric acid (IBA) was added to medium containing 4.4 μM BA during initiation of shoot multiplication, but not when added later. Direct multiple shoot initiation was also obtained from germinating seeds in the presence of BA alone. Rooting was successful in excised shoots grown on growth regulator-free MS medium. Rooted shoots were successfully established in soil in a greenhouse.
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TL;DR: Both the quality and the quantity of light affect growth of plantlets, development of stomata and physiological responses differently depending on the intensity and the wavelength of light.
Abstract: The aim of the study was to establish whether the quantity and the quality of light affect growth and development of Withania somnifera plantlets. We have studied growth and histo-physiological parameters [stomatal characteristics, chloroplastic pigments concentrations, photosynthesis, and transpiration (E)] of W. somnifera plantlets regenerated under various light intensities, or monochromatic light or under a mixture of two colors of light in tissue culture conditions. Plantlets grown under a photon flux density (PFD) of 30 μmol m-2 s-1 showed greater growth and development than those raised under other PFDs. Chlorophylls and carotenoids, numbers of stomata, rate of photosynthesis (PN) and transpiration (E), stomatal conductance (gs), and water use efficiency (WUE) increased with increasing the PFD up to 60 μmol m-2 s-1. Light quality also affected plantlets growth and physiology. Highest growth was observed under fluorescent and in a mixture of blue and red light. Very few stomata were developed in any of the monochromatic light but under fluorescent or under a mixture of two colors stomatal numbers increased. Similarly, gs, E, PN, and WUE were also higher under fluorescent light and under a mixture of red and blue light. Regressional analysis showed a linear relationship between PN (r2 = 70) and gs and between E (r2 = 0.95) and gs. In conclusion, both the quality and the quantity of light affect growth of plantlets, development of stomata and physiological responses differently depending on the intensity and the wavelength of light.
169 citations
Cites background from "Micropropagation of Withania somnif..."
...Since this species propagates by means of seeds and does not have natural ability of vegetative propagation, it is difficult to fix variability generated by sexual recombination (Sen and Sharma 1991)....
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TL;DR: Although callus-free multiple-shoot formation was a function of cytokinin activity alone, faster bud break coupled with an enhanced frequency of shoot development and internode elongation were dependent on the synergistic influence of gibberellic acid (GA3) along with BA when used at an optimal concentration.
Abstract: A protocol is described for rapid and large-scale propagation of the woody aromatic and medicinal shrub Vitex negundo by in vitro culture of nodal segments from mature plants. Of the three different cytokinins – N6-benzyladenine (BA), kinetin, and thidiazuron – evaluated as supplements to Murashige and Skoog (MS) medium, BA at an optimal concentration of 2.0 mg/l was most effective in inducing bud break. Although callus-free multiple-shoot formation was a function of cytokinin activity alone, faster bud break coupled with an enhanced frequency of shoot development (92%) and internode elongation were dependent on the synergistic influence of gibberellic acid (GA3) when used at an optimal concentration (0.4 mg/l) along with BA (2.0 mg/l). The frequency of shoot proliferation was markedly influenced by the explanting season. By repeated subculturing of nodal segments harvested from the in vitro-formed axenic shoots on MS containing 1.0 mg/l BA and 0.4 mg/l GA3, prolific shoot cultures free from proximal callusing and showing a high-frequency multiplication rate were established. The percentage shoot multiplication (98–100%) as well as the number of shoots per node (six to eight) were highest during the first three culture passages, after which there was a gradual decline in shoot development. Rooting was best induced (94%) in shoots excised from proliferated shoot cultures on half-strength MS medium augmented with an optimal combination of indole-3-acetic acid and indole-3-butyric acid each at 1.0 mg/l. Vermi-compost was the most suitable planting substrate for hardening inside a plant growth chamber and its use ensured high-frequency survival (93%) of regenerated plants prior to outdoor transfer. Micropropagated plants established in garden soil were uniform and identical to the donor plant with respect to growth characteristics as well as vegetative and floral morphology.
149 citations
TL;DR: A procedure is outlined for in vitro propagation of two medicinal herbs, OCimum americanum L. canum Sims (hoary basil) and Ocimum sanctum L.'souvenir (holy basil), using axillary shoot buds using benzyladenine supplemented with BA to induce multiple shoot formation.
Abstract: A procedure is outlined for in vitro propagation of two medicinal herbs, Ocimum americanum L. syn. O. canum Sims (hoary basil) and Ocimum sanctum L. (holy basil), using axillary shoot buds. Multiple shoot formation was induced from shoot bud explants of both species on Murashige and Skoog medium (MS) supplemented with benzyladenine (BA). The optimum BA concentrations for shoot proliferation were 0.25 mg/l for O. americanum and 1.0 mg/l for O. sanctum. Incorporation of 0.5 mg/l gibberellic acid (GA3) along with BA in the culture medium resulted in a marked increase in the frequency of axillary branching as well as multiple shoot formation. Shoot buds collected between September through December were most responsive in culture. Shoots of O. americanum were rooted on half-strength MS supplemented with 1.0 mg/l indole-3-butyric acid (IBA), whereas O. sanctum rooted best on medium with 1.0 mg/l naphthaleneacetic acid (NAA). The plantlets were hardened off and successfully established in natural soil, where they grew and matured normally.
143 citations
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01 Jan 2010
TL;DR: The investigation of a case of occupational silicosis in Ohio is described and the impact of hospital-based reporting on surveillance forsilicosis is summarized.
Abstract: Silicosis — Continued Silicosis is a chronic lung disease associated with the inhalation and pulmonary deposition of dust that contains crystalline silica. Through the Sentinel Event Notification System for Occupational Risks (SENSOR)* program, CDC's National Institute for Occupational Safety and Health (NIOSH) is assessing practical models for implementing state-based surveillance of silicosis and linking follow-up intervention activities to surveillance reports. From 1989 through 1992, the Ohio Department of Health (ODH) SENSOR program identified silicosis cases through reports of Bureau of Workers' Compensation (BWC) claims, physician reports, and death certificates. The addition in 1993 of hospital discharge reports as an ascertainment source resulted in a substantial increase in the number of silicosis case reports identified annually (Table 1). This report describes the investigation of a case of occupational silicosis in Ohio and summarizes the impact of hospital-based reporting on surveillance for silicosis in Case Report In September 1991, a case report † was sent to ODH by an infectious disease specialist who was treating a 55-year-old sandblaster with advanced silicosis and an associated Mycobacterium kansasii infection § (2). In January 1992, NIOSH and ODH conducted a joint investigation at the worker's place of employment—a metal preparation shop—to evaluate current levels of exposure to respirable crystalline silica and to screen co-workers for silicosis. The investigation detected excessive exposures to respirable crystalline silica (2–5). Chest radiology revealed radiographic abnormalities consistent with pneumoconiosis in four of 16 current and former workers *SENSOR is a program of cooperative agreements with state health departments to develop surveillance and intervention strategies for selected occupational conditions. The National Institute for Occupational Safety and Health currently supports SENSOR silicosis programs in seven states and Wisconsin). † Case reports should be submitted for persons with a physician's provisional diagnosis of silicosis, a chest radiograph interpreted as consistent with silicosis, or pathologic findings consistent with silicosis (1).
107 citations
TL;DR: Callus cultures were initiated from axillary leaves, axillary shoots, hypocotyls, and root segments on Murashige and Skoog medium supplemented with 2,4-D and KN to establish axillary shoot base callus on MS medium containing BA.
Abstract: Callus cultures were initiated from axillary leaves, axillary shoots, hypocotyls, and root segments on Murashige and Skoog (MS) (1962) medium supplemented with 2,4-D (2 mg l−1) and KN (0.2 mg l−1). Shoots differentiated best from axillary shoot base callus on MS medium containing BA (2 mg l−1). Regenerated shoots rooted best on MS medium containing IBA (2 mg l−1) alone, and IBA (2 mg l−1) with IAA (2 mg l−1). Plantlets were transferred to pots containing sand and soil mixture, acclimatized in a culture room and afterwards transferred to the glasshouse.
85 citations
Cites methods from "Micropropagation of Withania somnif..."
...…in water for 24 h, washed with 5% (v/v) teepol solution (5 min), surface-sterilized with 0.1% mercuric chloride (12–13 min), washed 3–4 times with sterile double-distilled water, and inoculated on halfstrength MS medium with 1% (w/v) sucrose without any growth regulators (Sen and Sharma, 1991)....
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References
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01 Jan 1985
TL;DR: A large number of medicinal plant species are procured from the naturally growing flora which has resulted in a gradual depletion of the resources and warrant methods for systematic cultivation and preservation of valuable genotypes.
Abstract: A major part of modern chemotherapeutics and traditional drugs are derived from higher plants [1]. While a few medicinal plant species are cultivated, a large number of them are procured from the naturally growing flora which has resulted in a gradual depletion of the resources. These considerations warrant methods for systematic cultivation and preservation of valuable genotypes. Alternatively methods for in vitro production of known drugs and new biologically active principles would be of particular value.
38 citations
TL;DR: Stimulation of multiple shoot formation from almond embryos using 6-benzylaminopurine was studied and maximum shoot numbers and shoot growth were obtained with 2.5 μM in the growth medium.
Abstract: Stimulation of multiple shoot formation from almond embryos using 6-benzylaminopurine was studied. Maximum shoot numbers and shoot growth were obtained with 2.5 μM in the growth medium. Continuous multiple shoot formation from cut shoots was also achieved.
10 citations