In vitro studies on the induction of sporogenous tissue on leaves of cinnamon fern. I. Environmental factors

1972 ◽  
Vol 50 (12) ◽  
pp. 2673-2682 ◽  
Author(s):  
William H. Harvey ◽  
James D. Caponetti

Intact, set III, cinnamon fern cataphyll and frond primordia, which were shown to have no predisposition to fertility in situ, produced sporangia when excised and cultured under sterile conditions in Knudson's medium supplemented with various levels of sucrose and maintained on 11 different regimens of light, darkness, and temperature for 10 weeks. Increasing levels of sucrose resulted in increased fertility under all environmental conditions, but the highest percentage of fertility was obtained under conditions of continuous dark at 26 °C. As the length of the light phase of the photoperiods decreased, a progressive increase in induction of fertile leaves was observed, suggesting that periods of long light exposure are inhibitory to the initiation of sporangia. Conversely, as the light intensity was increased, an inhibition of sporophyll differentiation occurred. Sporangia excised from dark-induced sporophylls and cultured in the light produced viable spores which germinated yielding haploid gametophytes that ultimately produced sporophytes.

CORD ◽  
1999 ◽  
Vol 15 (02) ◽  
pp. 34
Author(s):  
C S Ranasinghe ◽  
L K Weerakoon ◽  
Y M H Liyanage ◽  
D T Mathes

The physiological status of in vitro-grown coconut (Cocos nucifera L.) plants during acclimatization was studied using nursery-raised seedlings as the control.  The percentage of open stomata in leaves of in vitro-grown coconut plants was high at the initial stage of acclimatization but decreased during the course of acclimatization indicating an improvement in stomatal regulation.  A progressive increase in the stomatal density, epicuticular wax deposition and leaf thickness in in vitro-grown plants was observed during acclimatization. As a result of the low light intensity, the epidermal cells of in vitro-grown plants were narrower and longer when compared to the control.  With the exposure of plants to increased light intensity, the cells became wider and shorter as observed in the control.   The leaf chlorophyll content was high in in vitro-grown plants under low light intensity.  With increasing light intensity, a reduction in leaf chlorophyll content in vitro-grown plants was observed and at the later stages of acclimatization, it was comparable to that of the control. Variations in the rates of photosynthesis and transpiration in vitro-grown plants were observed in response to the changing environmental conditions.  However, at the end of acclimatization, where the plants were ready to be transferred to the field, the physiological statuses of in vitro-grown coconut plants were comparable to that of nursery raised seedlings. The present study revealed that the embryo-cultured coconut plants could adjust well to the changing environmental conditions during acclimatization.


2018 ◽  
Vol 39 (4) ◽  
pp. 496-506 ◽  
Author(s):  
Nguyen Thuy Phuong Duyen ◽  
Tran Thi Van ◽  
Nguyen Thu Le Minh ◽  
Nguyen Thi Quynh

The arrow leaf abelmoschus rhizome (Hibiscus sagittifolius Kurz), or Sam Bo Chinhin Vietnamese, is a perennial suffrutex herb from which the tuber root is used as a medicine in folk remedy. This species is widely distributed and can be found on many terrains across South East Asia. With an aim to create a large number of uniform and high-quality H. sagittifolius transplants in vitro, effects of some environmental factors such as photoperiod and temperature on the photoautotrophic growth of H. sagittifoliusin vitro plants were investigated. In vitro single nodal cuttings, each with an unfolded leaf, were cultured photoautotrophically (without sucrose and vitamins) on mineral SH medium, under light intensity of 150 µmol m-2 s-1, temperature of 24oC ± 2oC, relative humidity (RH) of 55% ± 5% and three different photoperiods (8, 12 or 16 h d-1) in the first experiment. Commercial polypropylene bags (V = 1,000 ml), attached with two filter-paper membranes, were used as culture vessels. After 42 days of culture, H. sagittifolius plants under the photoperiod of 16 h d-1 had the greatestincreased fresh weight (502.3 mg/plt), increased dry weight (39.5 mg/plt) and leaf area (17.0 cm2) than those put under 8 hd-1or 12 h d-1. In addition, H. sagittifolius plants also showed statistical differences in growth when photoautotrophically cultured in different air temperature regimes, including 28/25oC (photo-/dark period), 25/25oC and 20/25oC. Increased fresh weight (775 mg/plt), increased dry weight (62 mg/plt) and leaf area (22.7 cm2) of in vitro H. sagittifolius plants were the greatest when temperature was maintained at 28 oC during photoperiod. On the contrary, the photoperiod temperature of 20oC resulted in the shortest shoot length and root length of H. sagittifoliusplants. In conclusion, this study proved that H. sagittifolius plants had the best growth when cultured on SH medium, without sucrose and vitamins supplementation, under light intensity of 150 µmol m-2 s-1, RH 55% ± 5%, photoperiod of 16 h d-1, temperature regime of 28/25oC(photo-/dark period). Citation: Nguyen Thuy Phuong Duyen, Tran Thi Van, Nguyen Le Thu Minh, Nguyen Thi Quynh, 2017. Effects of micro-environmental factors on the photoautotrophic growth of Hibiscus sagittifolius Kurz cultured in vitro. Tap chi Sinh hoc, 39(4): 496-506. DOI: 10.15625/0866-7160/v39n4.11030. *Corresponding author: [email protected] 7 September 2017, accepted 15 December 2017


1986 ◽  
Vol 64 (11) ◽  
pp. 2608-2616 ◽  
Author(s):  
Jean-Claude Fournioux ◽  
Roger Bessis

Two different types of morphogenesis are induced in vitro in the grapevine by changing the system of sealing the culture tubes (with or without Parafilm). The differences appear mainly in the degree of miniaturiation: the plants the most miniaturized, those with Parafilm, have all the characteristics of an immature juvenile state. The others, without Parafilm, show an intermediate morphology between the adult and the juvenile forms. It follows then that the importance of juvenile characters is linked to the degree of miniaturization. One of the effects of Parafilm is in the modification of the amount of CO2 in the atmosphere of the tubes: in excess during the dark phase and in severe shortage during the light phase. We have found then, that among all the environmental factors which could influence the morphogenesis of the grapevine in vitro, CO2 appears to play a relatively important role.


1985 ◽  
Vol 38 (4) ◽  
pp. 411 ◽  
Author(s):  
WR Edirisinghe ◽  
RG Wales

The metabolism of glucose by late pre implantation mouse embryos was studied in a variety of media whose composition had been changed to reflect the environmental conditions in the uterus more closely than do standard culture media. The effects of combinations of energy substrates, the presence or absence of amino acids and the level of potassium in the medium were investigated.


Weed Science ◽  
1981 ◽  
Vol 29 (3) ◽  
pp. 364-367 ◽  
Author(s):  
Bonnie L. Blanchette ◽  
G. A. Lee

The effects of temperature and dew period on infectivity of Puccinia chondrillina Bubak and Syd. and the effect of light intensity on uredospore germination were studied under controlled environmental conditions. When rush skeletonweed (Chondrilla juncea L.) plants were inoculated with uredospores at 8, 16, and 24 C, larger pustules developed faster at 24 C than at the cooler temperatures. The greatest amount of infection occurred at 8 and 16 C (75% of the leaf area infected compared to 25% at 24 C). The greater number of infection sites at cooler temperatures was coincident with an increase in uredospore germination at 8 and 16 C compared to 24 C. Increasing the dew period from 0 to 6 h increased the amount of infection by the rust. Light intensities as low as 0.5 klux significantly reduced uredospore germination on water agar. Germ tube growth was restricted significantly by light intensities of 2.5 to 4.5 klux. Applications of uredospores to aid in biological control of this serious weed would be most successful if made at dusk under cool temperatures when an extended dew period is expected.


Author(s):  
Javier Gomez-León ◽  
Johann Lopez-Navarro ◽  
Alicia Millanguir ◽  
Jesus David Castaño ◽  
Sven Zea

The macrolide (+)-discodermolide produced by the marine sponge Discodermia dissoluta shows promising antitumor, antimitotic, and immunosuppressive activity. However, the sustainable supply of any molecule requires much in situ and in vitro research to optimize and later obtain the molecule of interest. In this study, two culture systems—fixed and suspended—were evaluated at 15-m depth in two sites, Punta de Betín and Nenguange, in Santa Marta (Colombian Caribbean). Survival, growth, and production of (+)-discodermolide were recorded, with the suspended system resulting in better growth and survival, depending on the culture site. The influence of the different environmental factors on survival was also studied, and a negative correlation with temperature was observed. Salinity, solar radiation, organic matter, and water flow were not correlated. Finally, no significant differences in the production of (+)-discodermolide existed between the culture systems and study sites. Production ranged from 20 to 270 μg per gram of dry sponge.


Author(s):  
J. P. Revel

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.


Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.


Author(s):  
C. Jennermann ◽  
S. A. Kliewer ◽  
D. C. Morris

Peroxisome proliferator-activated receptor gamma (PPARg) is a member of the nuclear hormone receptor superfamily and has been shown in vitro to regulate genes involved in lipid metabolism and adipocyte differentiation. By Northern analysis, we and other researchers have shown that expression of this receptor predominates in adipose tissue in adult mice, and appears first in whole-embryo mRNA at 13.5 days postconception. In situ hybridization was used to find out in which developing tissues PPARg is specifically expressed.Digoxigenin-labeled riboprobes were generated using the Genius™ 4 RNA Labeling Kit from Boehringer Mannheim. Full length PPAR gamma, obtained by PCR from mouse liver cDNA, was inserted into pBluescript SK and used as template for the transcription reaction. Probes of average size 200 base pairs were made by partial alkaline hydrolysis of the full length transcripts. The in situ hybridization assays were performed as described previously with some modifications. Frozen sections (10 μm thick) of day 18 mouse embryos were cut, fixed with 4% paraformaldehyde and acetylated with 0.25% acetic anhydride in 1.0M triethanolamine buffer. The sections were incubated for 2 hours at room temperature in pre-hybridization buffer, and were then hybridized with a probe concentration of 200μg per ml at 70° C, overnight in a humidified chamber. Following stringent washes in SSC buffers, the immunological detection steps were performed at room temperature. The alkaline phosphatase labeled, anti-digoxigenin antibody and detection buffers were purchased from Boehringer Mannheim. The sections were treated with a blocking buffer for one hour and incubated with antibody solution at a 1:5000 dilution for 2 hours, both at room temperature. Colored precipitate was formed by exposure to the alkaline phosphatase substrate nitrobluetetrazoliumchloride/ bromo-chloroindlylphosphate.


2018 ◽  
Vol 12 (7-8) ◽  
pp. 38-45
Author(s):  
A. N. EFREMOV ◽  
N. V. PLIKINA ◽  
T. ABELI

Rare species are most vulnerable to man-made impacts, due to their biological characteristics or natural resource management. As a rule, the economic impact is associated with the destruction and damage of individual organisms, the destruction or alienation of habitats. Unfortunately, the conservation of habitat integrity is an important protection strategy, which is not always achievable in the implementation of industrial and infrastructural projects. The aim of the publication is to summarize the experience in the field of protection of rare species in the natural habitat (in situ), to evaluate and analyze the possibility of using existing methods in design and survey activities. In this regard, the main methodological approaches to the protection of rare species in the natural habitat (in situ) during the proposed economic activity were reflected. The algorithm suggested by the authors for implementing the in situ project should include a preparatory stage (initial data collection, preliminary risk assessments, technology development, obtaining permitting documentation), the main stage, the content of which is determined by the selected technology and a long monitoring stage, which makes it possible to assess the effectiveness of the taken measures. Among the main risks of in situ technology implementation, the following can be noted: the limited resources of the population that do not allow for the implementation of the procedure without prior reproduction of individuals in situ (in vitro); limited knowledge of the biology of the species; the possibility of invasion; the possibility of crossing for closely related species that сo-exist in the same habitat; social risks and consequences, target species or population may be important for the local population; financial risks during the recovery of the population. The available experience makes it possible to consider the approach to the conservation of rare species in situ as the best available technology that contributes to reducing negative environmental risks.


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